Loki: Document how to use the docker driver with a config file

[cyriltovena]

We should document how to embed a configuration file within the Loki Docker driver.

Steps to rebuild the docker drivers with your config basically.

[Strum355]

I can go through my shell history this evening (EU IST) for @raneq

[raneq]

Thank you @Strum355 , I can proofread and write what I miss for the README then :)

[cyriltovena]

You guys are awesome ❤️

[Strum355]

Unfortunately i havent been successful in getting it to work again, I had deleted the driver config.json and im getting the following errors trying to recreate what i had done (probably incorrectly):

 ~/G/loki   *…  make enable-plugin                                                                                                                                                                                                                                                                           
docker plugin enable grafana/loki-docker-driver:master-cb7c8f6
Error response from daemon: OCI runtime create failed: container_linux.go:345: starting container process caused "process_linux.go:430: container init caused \"rootfs_linux.go:58: mounting \\\"/home/noah/Netsoc/dev-env/nsa\\\" to rootfs \\\"/docker/plugins/3ce38f52d11d202d39bdc0289db39c062ef4280c23fb7a54a021f1b53c8143b8/rootfs\\\" at \\\"/docker/plugins/3ce38f52d11d202d39bdc0289db39c062ef4280c23fb7a54a021f1b53c8143b8/rootfs/home/noah/Netsoc/dev-env/nsa\\\" caused \\\"no such device\\\"\"": unknown

running make build-plugin didnt work a few times a well until i manually go get'd two packages :/

[raneq]

I tried to build it myself too. In a debian 9, in various iterations I've done:

git clone https://github.com/grafana/loki/
# make build-plugin → permission denied for docker
# sudo make build-plugin → make: go: Command not found

sudo apt install golang
# sudo make build-plugin →↓
# assets_generate.go:9:2: cannot find package "github.com/grafana/loki/pkg/promtail/server/ui" in any of:
#   /usr/lib/go-1.7/src/github.com/grafana/loki/pkg/promtail/server/ui (from $GOROOT)
#   ($GOPATH not set)
# assets_generate.go:10:2: cannot find package "github.com/prometheus/prometheus/pkg/modtimevfs" in any of:
#   /usr/lib/go-1.7/src/github.com/prometheus/prometheus/pkg/modtimevfs (from $GOROOT)
#   ($GOPATH not set)
# assets_generate.go:11:2: cannot find package "github.com/shurcooL/vfsgen" in any of:
#   /usr/lib/go-1.7/src/github.com/shurcooL/vfsgen (from $GOROOT)
#   ($GOPATH not set)

export GOPATH=/home/user/git/loki/
# sudo -E make build-plugin →↓
# CGO_ENABLED=0 go build -ldflags "-extldflags \"-static\" -s -w -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.Branch=master -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.Version=master-cb7c8f6 -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.Revision=cb7c8f6" -tags netgo -o cmd/docker-driver/docker-driver ./cmd/docker-driver
# go: disabling cache (/go/cache) due to initialization failure: mkdir /go/cache/00: permission denied
# # github.com/grafana/loki/cmd/docker-driver
# cmd/docker-driver/config.go:56:3: cannot use "github.com/grafana/loki/vendor/github.com/cortexproject/cortex/pkg/util".BackoffConfig literal (type "github.com/grafana/loki/vendor/github.com/cortexproject/cortex/pkg/util".BackoffConfig) as type "github.com/grafana/loki/vendor/github.com/grafana/loki/vendor/github.com/cortexproject/cortex/pkg/util".BackoffConfig in field value
# cmd/docker-driver/config.go:127:19: cannot use "github.com/grafana/loki/vendor/github.com/cortexproject/cortex/pkg/util/flagext".URLValue literal (type "github.com/grafana/loki/vendor/github.com/cortexproject/cortex/pkg/util/flagext".URLValue) as type "github.com/grafana/loki/vendor/github.com/grafana/loki/vendor/github.com/cortexproject/cortex/pkg/util/flagext".URLValue in assignment
# cmd/docker-driver/loki.go:38:76: cannot use "github.com/grafana/loki/vendor/github.com/prometheus/client_golang/prometheus".DefaultRegisterer (type "github.com/grafana/loki/vendor/github.com/prometheus/client_golang/prometheus".Registerer) as type "github.com/grafana/loki/vendor/github.com/grafana/loki/vendor/github.com/prometheus/client_golang/prometheus".Registerer in argument to stages.NewPipeline:
#   "github.com/grafana/loki/vendor/github.com/prometheus/client_golang/prometheus".Registerer does not implement "github.com/grafana/loki/vendor/github.com/grafana/loki/vendor/github.com/prometheus/client_golang/prometheus".Registerer (wrong type for MustRegister method)
#       have MustRegister(..."github.com/grafana/loki/vendor/github.com/prometheus/client_golang/prometheus".Collector)
#       want MustRegister(..."github.com/grafana/loki/vendor/github.com/grafana/loki/vendor/github.com/prometheus/client_golang/prometheus".Collector)
# cmd/docker-driver/loki.go:58:40: cannot use l.labels.Clone() (type "github.com/grafana/loki/vendor/github.com/prometheus/common/model".LabelSet) as type "github.com/grafana/loki/vendor/github.com/grafana/loki/vendor/github.com/prometheus/common/model".LabelSet in argument to l.handler.Handle
# Makefile:158: recipe for target 'cmd/docker-driver/docker-driver' failed
# make: *** [cmd/docker-driver/docker-driver] Error 2
# make: Leaving directory '/go/src/github.com/grafana/loki'
# Makefile:141: recipe for target 'cmd/docker-driver/docker-driver' failed
# make: *** [cmd/docker-driver/docker-driver] Error 2

# So there's some programming error. Let's checkout a stable version then. Look, there's release v0.1.0
git stash 
git checkout v0.1.0 -b v0.1.0
git stash pop
# sudo -E make build-plugin → make: *** No rule to make target 'build-plugin'.  Stop.

Is there some meta-stable release that includes the docker plug-in and that I can use to build?
Thank you!

[raneq]

Unfortunately i havent been successful in getting it to work again

Thank you a lot @Strum355 for trying!!

[wapmorgan]

Is there any ability to pass a config file without rebuilding the plugin?

[Strum355]

@wapmorgan https://github.com/grafana/loki/issues/694#issuecomment-513870139
TLDR if you can enforce all configs being in a folder specified at build-time, its possible

[wapmorgan]

@Strum355 at plugin build-time? Its really hard, because there can be few projects within one machine and one docker instance. If you mean image build-time, its possible.

[Strum355]

@wapmorgan you can set the folder in which all config files will be set at plugin build-time eg /docker/loki/configs/ and then at container run-times you can specify which config file to use from that folder

[cyriltovena]

@wapmorgan I could not find the answer on docker documentation.

[stale[bot]]

This issue has been automatically marked as stale because it has not had any activity in the past 30 days. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.

[nikel123]

Is it possible to add mounts to the plugin config? (as described here https://docs.docker.com/engine/extend/config/ and used in this plugin: https://github.com/vieux/docker-volume-sshfs). Then one could use 'docker plugin set' (https://docs.docker.com/engine/reference/commandline/plugin_set/ section about changing source of a mount).