tbeadle / postgres

Docker Official Image packaging for Postgres

About this Repo

This is a fork of the repo for generating the official Postgres docker images.

The following changes are incorporated:

• The environment variables PGUSER, PGPASSWORD, and PGDATABASE are used instead of POSTGRES_USER, POSTGRES_PASSWORD and POSTGRES_DB. This is so that those environment variables can be defined in a docker-compose.yml file for the database container and then be inherited by other services that need to connect to the database so that they can just define PGHOST to the name of the database container and then use 'psql' without any connection parameters.
• pg_hba.conf is changed to restrict external access to the database to 'samenet' instead of 'all'. This makes it so that other containers in the deployment can connect to it, but other external addresses are not able to.
• pgcli is installed as an alternative to the built-in psql command. (Only in the debian-based images)
• The suggestions for postgresql.conf taken from Christophe Pettus's excellent talk at https://www.youtube.com/watch?v=jqmdujimzfq are included.
• If any executable scripts are found in /docker-pre-entrypoint.d, then those scripts will be executed before initializing or starting the database. If any executable scripts are found in /docker-post-entrypoint.d, then those scripts will be executed immediately before starting the database. These directories are different from the standard /docker-entrypoint-initdb.d in that that directory will only be processed when the database did not already exist and is getting initialized. These directories are typically mounted as volumes for a container. If you create a Dockerfile that extends this image, there are directories that you can include in your image, which will not interfere with the ones already mentioned (allowing your image's users to continue using those):
  • /image-pre-entrypoint.d - Scripts in here run before those in /docker-pre-entrypoint.d.
  • /image-pre-start.d - Scripts in here run after initdb has been run but before postgres started for the first time. It can be used to modify postgresql.conf, for instance.
  • /image-entrypoint-initdb.d - Scripts in here run before those in /docker-entrypoint-initdb.d.
  • /image-post-entrypoint.d - Scripts in here run before those in /docker-post-entrypoint.d.
• There are some environment variables that can be used to tune the postgresql.conf:

Variable name	Description
LOG_MIN_DURATION_TIMEOUT	Cause statements taken longer than the given value to be logged. Defaults to 600ms.
CHECKPOINT_TIMEOUT	Set the maximum amount of time between checkpoints. Defaults to 20min.

The images are on docker hub at https://hub.docker.com/r/tbeadle/postgres/

To build the images, just run docker-compose build.

Using with barman for database backups

See the README.md in the barman directory for information on an image that can be used in conjunction with a barman server for backing up the database.