https://hub.docker.com/r/behance/docker-base/tags/

Ubuntu used by default, Alpine builds also available tagged as -alpine

Provides base OS, patches and stable nginx for quick and easy spinup.

S6 process supervisor is used for only for zombie reaping (as PID 1), boot coordination, and termination signal translation

Goss is used for build-time testing

To add a service to be monitored, simply create a service script: https://github.com/just-containers/s6-overlay#writing-a-service-script For programmatic switches, create the service in /etc/services-available, and symlink to /etc/services.d to enable

To inject changes just before runtime, shell scripts may be placed into the /etc/cont-init.d folder. As part of the process manager, these scripts are run in advance of the supervised processes. @see https://github.com/just-containers/s6-overlay#executing-initialization-andor-finalization-tasks

Container tests itself as part of build process using goss validator. To add additional tests, overwrite (or extend) the /goss.base.yaml file.

More advanced changes can take effect using the run.d system. Similar to the /etc/cont-init.d/ script system, any shell scripts (ending in .sh) in the /run.d/ folder will be executed ahead of the S6 initialization.

• If a run.d script terminates with a non-zero exit code, container will stop, terminating with the script's exit code, unless...
• If script terminates with exit code of $SIGNAL_BUILD_STOP (99), this will signal the container to stop cleanly. This can be used for a multi-stage build process

This container image can be used with multiple entrypoints (not to be confused with Docker entrypoints). For example, a codebase that runs a web service, but also requires crons and background workers. These processes should not run inside the same container (like a VM would), but can be executed separately from the same image artifact by adding arguments to the run command.

docker run {image_id} /worker.sh 3 /bin/binary -parameters -that -binary -receives

Runs 3 copies of /bin/binary that receives the parameters -parameters -that -binary -receives

Besides the instructions contained in the Dockerfile, the majority of this container's use is in configuration and process. The ./container/root repo directory is overlayed into a container during build. Adding additional files to the folders in there will be present in the final image. All paths from the following explanation are assumed from the repo's ./root/ base: