Unable to start sentry server [resolved] gcr.io blocked in china

After git clone and ./install.sh
I got:

[root@dev onpremise]# docker-compose up
Pulling relay (us.gcr.io/sentryio/relay:latest)…
ERROR: Get https://us.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)

curl that address I got:

[root@dev onpremise]# curl http s://us .gcr .io/v2/
{“errors”:[{“code”:“UNAUTHORIZED”,“message”:“Unauthorized access.”}]}

I’m using CentOS 7, a VMware virtual machine.
Network issue? I’m currently located in mainland china which has strict network censorship, so I have to visit google service via proxy (a Google Cloud box).
Don’t know if it has something to do with this.

If I’m blocked, is there an alternative / mirror for this URL that I can use?
Thanks.

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SOLUTION
I added HTTP_PROXY environment variable in /usr/lib/systemd/system/docker.service and restarted docker service, then I was able to pull that image in the end.

Sorry about this issue, should have used Docker Hub for this. Fix submitted: