Official Repository

Last pushed: 7 days ago

Supported tags and respective Dockerfile links

For more information about this image and its history, please see the relevant manifest file (library/postgres). This image is updated via pull requests to the docker-library/official-images GitHub repo.

What is PostgreSQL?

PostgreSQL, often simply "Postgres", is an object-relational database management system (ORDBMS) with an emphasis on extensibility and standards-compliance. As a database server, its primary function is to store data, securely and supporting best practices, and retrieve it later, as requested by other software applications, be it those on the same computer or those running on another computer across a network (including the Internet). It can handle workloads ranging from small single-machine applications to large Internet-facing applications with many concurrent users. Recent versions also provide replication of the database itself for security and scalability.

PostgreSQL implements the majority of the SQL:2011 standard, is ACID-compliant and transactional (including most DDL statements) avoiding locking issues using multiversion concurrency control (MVCC), provides immunity to dirty reads and full serializability; handles complex SQL queries using many indexing methods that are not available in other databases; has updateable views and materialized views, triggers, foreign keys; supports functions and stored procedures, and other expandability, and has a large number of extensions written by third parties. In addition to the possibility of working with the major proprietary and open source databases, PostgreSQL supports migration from them, by its extensive standard SQL support and available migration tools. And if proprietary extensions had been used, by its extensibility that can emulate many through some built-in and third-party open source compatibility extensions, such as for Oracle.

wikipedia.org/wiki/PostgreSQL

logo

How to use this image

start a postgres instance

$ docker run --name some-postgres -e POSTGRES_PASSWORD=mysecretpassword -d postgres

This image includes EXPOSE 5432 (the postgres port), so standard container linking will make it automatically available to the linked containers. The default postgres user and database are created in the entrypoint with initdb.

The postgres database is a default database meant for use by users, utilities and third party applications.

connect to it from an application

$ docker run --name some-app --link some-postgres:postgres -d application-that-uses-postgres

... or via psql

$ docker run -it --link some-postgres:postgres --rm postgres sh -c 'exec psql -h "$POSTGRES_PORT_5432_TCP_ADDR" -p "$POSTGRES_PORT_5432_TCP_PORT" -U postgres'

Environment Variables

The PostgreSQL image uses several environment variables which are easy to miss. While none of the variables are required, they may significantly aid you in using the image.

POSTGRES_PASSWORD

This environment variable is recommended for you to use the PostgreSQL image. This environment variable sets the superuser password for PostgreSQL. The default superuser is defined by the POSTGRES_USER environment variable. In the above example, it is being set to "mysecretpassword".

POSTGRES_USER

This optional environment variable is used in conjunction with POSTGRES_PASSWORD to set a user and its password. This variable will create the specified user with superuser power and a database with the same name. If it is not specified, then the default user of postgres will be used.

PGDATA

This optional environment variable can be used to define another location - like a subdirectory - for the database files. The default is /var/lib/postgresql/data, but if the data volume you're using is a fs mountpoint (like with GCE persistent disks), Postgres initdb recommends a subdirectory (for example /var/lib/postgresql/data/pgdata ) be created to contain the data.

How to extend this image

If you would like to do additional initialization in an image derived from this one, add one or more *.sql or *.sh scripts under /docker-entrypoint-initdb.d (creating the directory if necessary). After the entrypoint calls initdb to create the default postgres user and database, it will run any *.sql files and source any *.sh scripts found in that directory to do further initialization before starting the service.

These initialization files will be executed in sorted name order as defined by the current locale, which defaults to en_US.utf8. Any *.sql files will be executed by POSTGRES_USER, which defaults to the postgres superuser. It is recommended that any psql commands that are run inside of a *.sh script be executed as POSTGRES_USER by using the --username "$POSTGRES_USER" flag. This user will be able to connect without a password due to the presence of trust authentication for Unix socket connections made inside the container.

You can also extend the image with a simple Dockerfile to set a different locale. The following example will set the default locale to de_DE.utf8:

FROM postgres:9.4
RUN localedef -i de_DE -c -f UTF-8 -A /usr/share/locale/locale.alias de_DE.UTF-8
ENV LANG de_DE.utf8

Since database initialization only happens on container startup, this allows us to set the language before it is created.

Caveats

If there is no database when postgres starts in a container, then postgres will create the default database for you. While this is the expected behavior of postgres, this means that it will not accept incoming connections during that time. This may cause issues when using automation tools, such as fig, that start several containers simultaneously.

Supported Docker versions

This image is officially supported on Docker version 1.8.1.

Support for older versions (down to 1.0) is provided on a best-effort basis.

User Feedback

Documentation

Documentation for this image is stored in the postgres/ directory of the docker-library/docs GitHub repo. Be sure to familiarize yourself with the repository's README.md file before attempting a pull request.

Issues

If you have any problems with or questions about this image, please contact us on the or through a GitHub issue.

You can also reach many of the official image maintainers via the #docker-library IRC channel on Freenode.

Contributing

You are invited to contribute new features, fixes, or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.

Before you start to code, we recommend discussing your plans on the or through a GitHub issue, especially for more ambitious contributions. This gives other contributors a chance to point you in the right direction, give you feedback on your design, and help you find out if someone else is working on the same thing.


Comments (64)
georged
a year ago

I'm curious as to why the examples don't have any mapped volumes. Is the data intended to be stored inside the container?

namxam
a year ago

Yeah, I actually asked myself the exact same thing ;)

ubergarm
a year ago

docker run --name my_postgres \
-d \
-v pwd/volumes/data:/var/lib/postgresql/data \
postgres

Note that the postgres container uses uid/gid:
postgres:x:999:999

The config file in the container is at: /var/lib/postgresql/data/postgresql.conf

georged
a year ago

Fantastic, thanks @ubergarm. That works nicely for me.

georged
a year ago

If anyone is wondering how to install extensions, there is a contrib directory inside the container. To install hstore I made a Dockerfile that ran the following:

RUN cd contrib/hstore && make && make install

Creating the extension with CREATE EXTENSION then succeeds.

cryptix
a year ago

I'd like to make my own Image based on this one, basically just loading my schema into the db but I don't know how to startup the db without it blocking further execution.

I could write my own docker-entrypoint.sh script but I wanted to see if there is another way, using this as a base, as it is.

my Dockerfile so far: https://gist.github.com/72aa47fba3afa5730b5d

geetotes
a year ago

Where can I see the Dockerfile for this image?

jberkus
a year ago

Hey, I'd like to have the PostgreSQL community, meaning probably me, take over maintenance of this Official Image. How do I go about doing that?

tianon
a year ago

brainopia
a year ago

The encoding of the template database is ASCII, not UTF-8 :(

DOCKER PULL COMMAND
Description

The PostgreSQL object-relational database system provides reliability and data integrity.