Docker images
Last updated
Last updated
We're trying to solve the most common problems that everybody stumbles upon while building complex and production-ready docker images.
We use supervisord to run multiple (unix processes) in the background. A real web application needs more than just a webserver. E.g. a cron daemon to run scheduled processes, postfix to send mails, etc.
Docker is designed to run only a single process in the foreground and use the console output as logs. You can then of docker containers to gelf, fluentd, splunk or something else.
But when running multiple processes, you must redirect all outputs to stderr/stdout of those processes. We configured all our services not to write container internal files but to output everything on stdout/stderr.
It's best practice of building Docker images to use ENV variables to control the configuration of the service that is running in a container. We try to provide all common needed configuration options which can by quite tricky if you think about PHP with all the fpm parameters, ini parameters, etc.
We try to keep you from building your own Docker images as good as possible and not to mount config files or similar.
To be written
To be written
DRY, etc.
To write: Example dependency tree of php-nginx-dev with explanation of distro tagging
As our images are very well encapsulated depending on the use case, we have 3 levels of base images:
Bootstrap
Base
Base-App
In this first layer we add some useful scripts like (just an excerpt):
apt-install
go-replace
gosu
This simplifies the usage of the package managers for each linux distribution. They are optimized to be used in a Docker environment. They update, install silently and cleanup afterwards.
The bootstrap images ensure that the foreign but official images are up-to-date as we don't trust that the basic packages are properly updated on the basic builds of the official images.
The base images e.g. webdevops/base:debian-9 can be considered as the first layer of "real" WebDevOps images. They extend the bootstrap images and add our layer of provisioning scripts together with the supervisor daemon to use multiple service processes inside an image.
The bootstrap images e.g. webdevops/bootstrap:debian-9 are the first layer of our images extending the official images like e.g. debian, ubuntu or php with our .
See the for more details.
From this point on you can use our custom service commands, and .
See the for more details.
The base-app images e.g. webdevops/base-app:debian-9 extend the base images. They contain some common needed tools like git, zip, rsync, open-ssh and the .
See the for more details.