Promtail docker run instructions refer to stale-version tag "master"

When working in the Grafana Cloud UI and adding a Loki integration, or when working in the Grafana Stack UI and reading instructions under #sending-logs, you’ll find an instruction for running promtail via Docker like:

docker run --name promtail --volume "$PWD/promtail:/etc/promtail" --volume "/var/log:/var/log" grafana/promtail:master -config.file=/etc/promtail/config.yaml

The problem with this command is the :master tag qualifier on the Docker image - it points to an old version of the grafana/promtail image. This is likely a result of moving from master to main as the default branch.

You can see this by running promtail --version in each tag - master, main and latest (or empty/default):


docker run -it --rm --entrypoint /usr/bin/promtail grafana/promtail:master --version
promtail, version main-678495a (branch: main, revision: 678495a97)
  build user:       root@c6deb26914dd
  build date:       2021-11-04T20:53:06Z
  go version:       go1.17.2
  platform:         linux/amd64


docker run -it --rm --entrypoint /usr/bin/promtail grafana/promtail:main --version
promtail, version main-dcfba36 (branch: main, revision: dcfba366d)
  build user:       root@2503cb5de62a
  build date:       2022-09-26T20:55:11Z
  go version:       go1.18.5
  platform:         linux/amd64


docker run -it --rm --entrypoint /usr/bin/promtail grafana/promtail:latest --version
promtail, version 2.6.1 (branch: HEAD, revision: 6bd05c9a4)
  build user:       root@458047b5501a
  build date:       2022-07-18T08:48:45Z
  go version:       go1.17.9
  platform:         linux/amd64

Suggestion: replace master with either main (HEAD) or empty/latest (release) in both/all locations. Release seems reasonable to me, so latest or empty. This would use 2.6.1 as of today. Or use main to be on the latest/bleeding-edge.

Is it sufficient to suggest this here, or is a support/bug ticket better?


Hey @javabrett ! Thanks for reporting this. The forum is a great place to request features, report experiences/bugs, or give some feedback.
Regarding the issue at hand, it seems it remained unchanged after the Loki team renamed the branch. Just submitted a PR fixing this.

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