When cloud run (container service on google cloud platform) starts a new service revision it grants computation resources for initialization. These resources will we revoked when the maximum startup time is reached or the service opens a receiving socket. In case when the service opens the socket before startup has finished (as it can be the case with particular spring boot configurations) the service is throttled and cannot finish startup anymore.
runproxy is a small tcp proxy that checks the service if it has come up yet (e.g. via a magic line appearing in the log output) and subsequently opens a socket to signal cloud run that the container is ready.
runproxy \
# listen on 0.0.0.0:8080 and forward tcp conns to 127.0.0.1:8181
-l 0.0.0.0:8080 \
-d 127.0.0.1:8181 \
# assume the app has been started if the following pattern matches a line in the stdout output
-m '^.*Started application in.*seconds.*$' \
# the command line to launch the downstream app
-- java -jar app.jar- Make sure the output channel of your service is unbuffered. In case of python use -u flag.
Copyright (c) 2022 by Cornelius Buschka.