Add php test case file.
diff --git a/tools/interop_matrix/client_matrix.py b/tools/interop_matrix/client_matrix.py
index 5e151c3..18e9341 100644
--- a/tools/interop_matrix/client_matrix.py
+++ b/tools/interop_matrix/client_matrix.py
@@ -30,6 +30,7 @@
     'python': ['python'],
     'node': ['node'],
     'ruby': ['ruby'],
+    'php': ['php', 'php7'],
 }
 
 # Dictionary of releases per language.  For each language, we need to provide
@@ -63,7 +64,7 @@
         'v1.7.0',
     ],
     'python': [
-        'v1.0.1',  #Fail to build. Investigating.
+        #'v1.0.x',  #Fail to run the test. #13230.
         'v1.1.4',
         'v1.2.5',
         'v1.3.9',
@@ -79,12 +80,19 @@
         'v1.6.6',
     ],
     'ruby': [
-        #'v1.0.1',  Can't run the tests because with_rvm.sh is missing.
+        # Ruby v1.0.x doesn't have the fix #8914, therefore not supported.
         'v1.1.4',
         'v1.2.5',
         'v1.3.9',
         'v1.4.2',
         'v1.6.6',
     ],
-
+    'php': [
+        'v1.0.1',
+        'v1.1.4',
+        'v1.2.5',
+        'v1.3.9',
+        'v1.4.2',
+        'v1.6.6',
+    ],
 }
diff --git a/tools/interop_matrix/testcases/php__master b/tools/interop_matrix/testcases/php__master
new file mode 100755
index 0000000..bce1d30
--- /dev/null
+++ b/tools/interop_matrix/testcases/php__master
@@ -0,0 +1,20 @@
+#!/bin/bash
+echo "Testing ${docker_image:=grpc_interop_php:b290f404-9940-4968-8fc2-19f5291c8eb7}"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=large_unary"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_unary"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=ping_pong"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_stream"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=client_streaming"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=server_streaming"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_begin"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_first_response"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=timeout_on_sleeping_server"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=large_unary"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_unary"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=ping_pong"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=empty_stream"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=client_streaming"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=server_streaming"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_begin"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=cancel_after_first_response"
+docker run -i --rm=true -w /var/local/git/grpc --net=host $docker_image bash -c "src/php/bin/interop_client.sh --server_host=216.239.32.254 --server_host_override=grpc-test4.sandbox.googleapis.com --server_port=443 --use_tls=true --test_case=timeout_on_sleeping_server"