This webservice provides live data on Docker containers. It takes data from the Linux kernel control groups and from the namespace of the container and expose them through a HTTP API.

This software is currently used in production.

From environment

• PORT: port to bind (4244 by default)
• DOCKER_URL: docker endpoint (http://127.0.0.1:4243 by default)
• REFRESH_TIME: number of second between CPU/net refresh (1 by default)
• PROC_DIR: mountpoint for procfs (default to /proc)
• CGROUP_DIR: mountpoint of cgroups (default to /sys/fs/cgroup)
• CGROUP_SOURCE: "docker" or "systemd" (docker by default) docker: /sys/fs/cgroup/:cgroup/memory/docker systemd: /sys/fs/cgroup/:cgroup/memory/system.slice/docker-#{id}.slice
• DEBUG: output of debugging information (default "false", switch to "true" to enable)

Run from docker:

docker run -v /sys/fs/cgroup:/host/cgroup:ro         -e CGROUP_DIR=/host/cgroup \
           -v /proc:/host/proc:ro                    -e PROC_DIR=/host/proc \
           -v /var/run/docker.sock:/host/docker.sock -e DOCKER_URL=unix:///host/docker.sock \
           -p 4244:4244 --privileged --pid=host --network=host \
           -d scalingo/acadock-monitoring

• --pid=host: The daemon has to find the real /proc/#{pid}/ns directory to enter a namespace
• --network=host: Acadock should in the host namespace to access other containers network namespaces (for network metrics)
• --privileged: Acadock has to enter the other containers namespaces

• Memory consumption

  GET /containers/:id/mem

  Return 200 OK Content-Type: application/json

{
  "mem_usage": 123,
  "mem_limit": 5000,
  "max_mem_usage": 500,
  "max_swap_mem_usage": 200,
  "swap_mem_usage": 145,
  "swap_mem_limit": 1000
}

• CPU usage (percentage)

  Return 200 OK Content-Type: text/plain GET /containers/:id/cpu

• Network usage (bytes and percentage)

  Return 200 OK Content-Type: application/json GET /containers/:id/net

• Mem+CPU+Network for a container

  Return 200 OK Content-Type: application/json GET /containers/:id/usage

• Mem+CPU+Network for all containers

  Return 200 OK Content-Type: application/json GET /containers/usage

Bump new version number in:

• CHANGELOG.md
• README.md

Commit, tag and create a new release:

version="1.2.1"

git switch --create release/${version}
git add CHANGELOG.md README.md
git commit -m "Bump v${version}"
git push --set-upstream origin release/${version}
gh pr create --reviewer=EtienneM --fill-first

Once the pull request merged, you can tag the new release.

git tag v${version}
git push origin master v${version}
gh release create v${version} --generate-notes --prerelease
gh release view v${version} --web

Build locally the archives. You can use the following command, it will automatically use the version of the last tag created.

goreleaser release --skip=publish,announce,sign --clean

On the web interface, unset the pre-release checkbox, check the "Set as the latest release" checkbox, and upload the archives in the dist folder.

Last, update the default version installed in the cookbook.