I've followed the directions here, and everything works well until I restart my computer. After restarting, it seems like the docker daemon loses track of the Google credentials.
$ docker run --log-driver=gcplogs ...
fails with:
docker: Error response from daemon: failed to initialize logging driver: google: could not find default credentials. See https://developers.google.com/accounts/docs/application-default-credentials for more information.
ERRO[0000] error waiting for container: context canceled
This is strange to me, because running $ systemctl show --property=Environment docker returns the value in my systemd configuration:
Environment=GOOGLE_APPLICATION_CREDENTIALS=/etc/path/to/application_default_credentials.json
If I $ sudo systemctl restart docker, then docker runs sucessfully and logs are sent to stackdriver. But I want this docker image to run automatically on startup, and restarting docker with sudo gets in the way.
Is there a way to initialize the docker daemon with the necessary environment variables, so gcplogs is ready on boot without restarting docker?
I had two versions of docker installed -- one through adding docker's repo to apt, and one through snap. Running
sudo systemctl list-unit-files| grep docker | grep enabled
showed two installations of docker:
docker.service enabled
snap.docker.dockerd.service enabled
Having two docker installations was causing problems for startup. I removed the snap installation, rebooted, and everything now works.