docs: update generated docs (#981)

diff --git a/docs/dyn/compute_v1.urlMaps.html b/docs/dyn/compute_v1.urlMaps.html
index c4499a6..3a32e5a 100644
--- a/docs/dyn/compute_v1.urlMaps.html
+++ b/docs/dyn/compute_v1.urlMaps.html
@@ -154,6 +154,7 @@
             "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
             "defaultRouteAction": { # defaultRouteAction takes effect when none of the  hostRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
                 # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+                # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within defaultRouteAction.
               "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
                 "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                     # Default is false.
@@ -224,6 +225,7 @@
                 "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
               },
               "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                  # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                 "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                     # The value must be between 1 and 255 characters.
                 "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -334,6 +336,7 @@
               { # A matcher for the path portion of the URL. The BackendService from the longest-matched rule will serve the URL. If no rule was matched, the default service will be used.
                 "defaultRouteAction": { # defaultRouteAction takes effect when none of the  pathRules or routeRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
                     # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+                    # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathMatcher's defaultRouteAction.
                   "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
                     "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                         # Default is false.
@@ -404,6 +407,7 @@
                     "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
                   },
                   "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                      # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                     "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                         # The value must be between 1 and 255 characters.
                     "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -511,6 +515,7 @@
                     ],
                     "routeAction": { # In response to a matching path, the load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If routeAction specifies any  weightedBackendServices, service must not be set. Conversely if service is set, routeAction cannot contain any  weightedBackendServices.
                         # Only one of routeAction or urlRedirect must be set.
+                        # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathRule's routeAction.
                       "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
                         "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                             # Default is false.
@@ -581,6 +586,7 @@
                         "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
                       },
                       "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                          # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                         "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                             # The value must be between 1 and 255 characters.
                         "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -835,6 +841,7 @@
                         "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
                       },
                       "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                          # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                         "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                             # The value must be between 1 and 255 characters.
                         "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -1063,6 +1070,7 @@
     "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
     "defaultRouteAction": { # defaultRouteAction takes effect when none of the  hostRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
         # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+        # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within defaultRouteAction.
       "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
         "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
             # Default is false.
@@ -1133,6 +1141,7 @@
         "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
       },
       "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+          # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
         "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
             # The value must be between 1 and 255 characters.
         "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -1243,6 +1252,7 @@
       { # A matcher for the path portion of the URL. The BackendService from the longest-matched rule will serve the URL. If no rule was matched, the default service will be used.
         "defaultRouteAction": { # defaultRouteAction takes effect when none of the  pathRules or routeRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
             # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+            # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathMatcher's defaultRouteAction.
           "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
             "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                 # Default is false.
@@ -1313,6 +1323,7 @@
             "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
           },
           "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+              # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
             "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                 # The value must be between 1 and 255 characters.
             "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -1420,6 +1431,7 @@
             ],
             "routeAction": { # In response to a matching path, the load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If routeAction specifies any  weightedBackendServices, service must not be set. Conversely if service is set, routeAction cannot contain any  weightedBackendServices.
                 # Only one of routeAction or urlRedirect must be set.
+                # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathRule's routeAction.
               "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
                 "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                     # Default is false.
@@ -1490,6 +1502,7 @@
                 "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
               },
               "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                  # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                 "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                     # The value must be between 1 and 255 characters.
                 "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -1744,6 +1757,7 @@
                 "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
               },
               "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                  # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                 "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                     # The value must be between 1 and 255 characters.
                 "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -1851,6 +1865,7 @@
   "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
   "defaultRouteAction": { # defaultRouteAction takes effect when none of the  hostRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
       # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+      # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within defaultRouteAction.
     "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
       "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
           # Default is false.
@@ -1921,6 +1936,7 @@
       "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
     },
     "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+        # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
       "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
           # The value must be between 1 and 255 characters.
       "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -2031,6 +2047,7 @@
     { # A matcher for the path portion of the URL. The BackendService from the longest-matched rule will serve the URL. If no rule was matched, the default service will be used.
       "defaultRouteAction": { # defaultRouteAction takes effect when none of the  pathRules or routeRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
           # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+          # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathMatcher's defaultRouteAction.
         "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
           "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
               # Default is false.
@@ -2101,6 +2118,7 @@
           "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
         },
         "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+            # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
           "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
               # The value must be between 1 and 255 characters.
           "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -2208,6 +2226,7 @@
           ],
           "routeAction": { # In response to a matching path, the load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If routeAction specifies any  weightedBackendServices, service must not be set. Conversely if service is set, routeAction cannot contain any  weightedBackendServices.
               # Only one of routeAction or urlRedirect must be set.
+              # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathRule's routeAction.
             "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
               "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                   # Default is false.
@@ -2278,6 +2297,7 @@
               "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
             },
             "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
               "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                   # The value must be between 1 and 255 characters.
               "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -2532,6 +2552,7 @@
               "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
             },
             "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
               "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                   # The value must be between 1 and 255 characters.
               "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -2809,6 +2830,7 @@
         "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
         "defaultRouteAction": { # defaultRouteAction takes effect when none of the  hostRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
             # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+            # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within defaultRouteAction.
           "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
             "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                 # Default is false.
@@ -2879,6 +2901,7 @@
             "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
           },
           "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+              # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
             "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                 # The value must be between 1 and 255 characters.
             "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -2989,6 +3012,7 @@
           { # A matcher for the path portion of the URL. The BackendService from the longest-matched rule will serve the URL. If no rule was matched, the default service will be used.
             "defaultRouteAction": { # defaultRouteAction takes effect when none of the  pathRules or routeRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
                 # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+                # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathMatcher's defaultRouteAction.
               "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
                 "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                     # Default is false.
@@ -3059,6 +3083,7 @@
                 "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
               },
               "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                  # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                 "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                     # The value must be between 1 and 255 characters.
                 "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -3166,6 +3191,7 @@
                 ],
                 "routeAction": { # In response to a matching path, the load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If routeAction specifies any  weightedBackendServices, service must not be set. Conversely if service is set, routeAction cannot contain any  weightedBackendServices.
                     # Only one of routeAction or urlRedirect must be set.
+                    # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathRule's routeAction.
                   "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
                     "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                         # Default is false.
@@ -3236,6 +3262,7 @@
                     "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
                   },
                   "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                      # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                     "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                         # The value must be between 1 and 255 characters.
                     "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -3490,6 +3517,7 @@
                     "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
                   },
                   "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                      # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                     "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                         # The value must be between 1 and 255 characters.
                     "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -3628,6 +3656,7 @@
   "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
   "defaultRouteAction": { # defaultRouteAction takes effect when none of the  hostRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
       # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+      # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within defaultRouteAction.
     "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
       "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
           # Default is false.
@@ -3698,6 +3727,7 @@
       "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
     },
     "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+        # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
       "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
           # The value must be between 1 and 255 characters.
       "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -3808,6 +3838,7 @@
     { # A matcher for the path portion of the URL. The BackendService from the longest-matched rule will serve the URL. If no rule was matched, the default service will be used.
       "defaultRouteAction": { # defaultRouteAction takes effect when none of the  pathRules or routeRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
           # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+          # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathMatcher's defaultRouteAction.
         "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
           "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
               # Default is false.
@@ -3878,6 +3909,7 @@
           "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
         },
         "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+            # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
           "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
               # The value must be between 1 and 255 characters.
           "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -3985,6 +4017,7 @@
           ],
           "routeAction": { # In response to a matching path, the load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If routeAction specifies any  weightedBackendServices, service must not be set. Conversely if service is set, routeAction cannot contain any  weightedBackendServices.
               # Only one of routeAction or urlRedirect must be set.
+              # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathRule's routeAction.
             "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
               "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                   # Default is false.
@@ -4055,6 +4088,7 @@
               "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
             },
             "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
               "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                   # The value must be between 1 and 255 characters.
               "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -4309,6 +4343,7 @@
               "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
             },
             "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
               "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                   # The value must be between 1 and 255 characters.
               "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -4485,6 +4520,7 @@
   "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
   "defaultRouteAction": { # defaultRouteAction takes effect when none of the  hostRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
       # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+      # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within defaultRouteAction.
     "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
       "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
           # Default is false.
@@ -4555,6 +4591,7 @@
       "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
     },
     "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+        # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
       "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
           # The value must be between 1 and 255 characters.
       "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -4665,6 +4702,7 @@
     { # A matcher for the path portion of the URL. The BackendService from the longest-matched rule will serve the URL. If no rule was matched, the default service will be used.
       "defaultRouteAction": { # defaultRouteAction takes effect when none of the  pathRules or routeRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
           # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+          # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathMatcher's defaultRouteAction.
         "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
           "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
               # Default is false.
@@ -4735,6 +4773,7 @@
           "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
         },
         "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+            # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
           "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
               # The value must be between 1 and 255 characters.
           "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -4842,6 +4881,7 @@
           ],
           "routeAction": { # In response to a matching path, the load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If routeAction specifies any  weightedBackendServices, service must not be set. Conversely if service is set, routeAction cannot contain any  weightedBackendServices.
               # Only one of routeAction or urlRedirect must be set.
+              # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathRule's routeAction.
             "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
               "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                   # Default is false.
@@ -4912,6 +4952,7 @@
               "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
             },
             "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
               "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                   # The value must be between 1 and 255 characters.
               "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -5166,6 +5207,7 @@
               "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
             },
             "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
               "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                   # The value must be between 1 and 255 characters.
               "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -5343,6 +5385,7 @@
       "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
       "defaultRouteAction": { # defaultRouteAction takes effect when none of the  hostRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
           # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+          # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within defaultRouteAction.
         "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
           "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
               # Default is false.
@@ -5413,6 +5456,7 @@
           "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
         },
         "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+            # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
           "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
               # The value must be between 1 and 255 characters.
           "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -5523,6 +5567,7 @@
         { # A matcher for the path portion of the URL. The BackendService from the longest-matched rule will serve the URL. If no rule was matched, the default service will be used.
           "defaultRouteAction": { # defaultRouteAction takes effect when none of the  pathRules or routeRules match. The load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If defaultRouteAction specifies any weightedBackendServices, defaultService must not be set. Conversely if defaultService is set, defaultRouteAction cannot contain any  weightedBackendServices.
               # Only one of defaultRouteAction or defaultUrlRedirect must be set.
+              # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathMatcher's defaultRouteAction.
             "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
               "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                   # Default is false.
@@ -5593,6 +5638,7 @@
               "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
             },
             "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
               "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                   # The value must be between 1 and 255 characters.
               "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -5700,6 +5746,7 @@
               ],
               "routeAction": { # In response to a matching path, the load balancer performs advanced routing actions like URL rewrites, header transformations, etc. prior to forwarding the request to the selected backend. If routeAction specifies any  weightedBackendServices, service must not be set. Conversely if service is set, routeAction cannot contain any  weightedBackendServices.
                   # Only one of routeAction or urlRedirect must be set.
+                  # UrlMaps for external HTTP(S) load balancers support only the urlRewrite action within a pathRule's routeAction.
                 "corsPolicy": { # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing # The specification for allowing client side cross-origin requests. Please see W3C Recommendation for Cross Origin Resource Sharing
                   "allowCredentials": True or False, # In response to a preflight request, setting this to true indicates that the actual request can include user credentials. This translates to the Access-Control-Allow-Credentials header.
                       # Default is false.
@@ -5770,6 +5817,7 @@
                   "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
                 },
                 "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                    # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                   "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                       # The value must be between 1 and 255 characters.
                   "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.
@@ -6024,6 +6072,7 @@
                   "seconds": "A String", # Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years
                 },
                 "urlRewrite": { # The spec for modifying the path before sending the request to the matched backend service. # The spec to modify the URL of the request, prior to forwarding the request to the matched service.
+                    # urlRewrite is the only action supported in UrlMaps for external HTTP(S) load balancers.
                   "hostRewrite": "A String", # Prior to forwarding the request to the selected service, the request's host header is replaced with contents of hostRewrite.
                       # The value must be between 1 and 255 characters.
                   "pathPrefixRewrite": "A String", # Prior to forwarding the request to the selected backend service, the matching portion of the request's path is replaced by pathPrefixRewrite.