add comments for health check docker flags
diff --git a/tools/run_tests/run_interop_tests.py b/tools/run_tests/run_interop_tests.py
index fb10a44..48f2978 100755
--- a/tools/run_tests/run_interop_tests.py
+++ b/tools/run_tests/run_interop_tests.py
@@ -687,6 +687,14 @@
itertools.chain.from_iterable(('-p', str(_DEFAULT_SERVER_PORT + i))
for i in range(
len(_HTTP2_BADSERVER_TEST_CASES))))
+ # Enable docker's healthcheck mechanism.
+ # This runs a Python script inside the container every second. The script
+ # pings the http2 server to verify it is ready. The 'health-retries' flag
+ # specifies the number of consecutive failures before docker will report
+ # the container's status as 'unhealthy'. Prior to the first 'health_retries'
+ # failures or the first success, the status will be 'starting'. 'docker ps'
+ # or 'docker inspect' can be used to see the health of the container on the
+ # command line.
docker_args += [
'--health-cmd=python test/http2_test/http2_server_health_check.py '
'--server_host=%s --server_port=%d'