bitnami-containers/bitnami/postgresql

What is PostgreSQL?

PostgreSQL is an object-relational database management system (ORDBMS) with an emphasis on extensibility and on standards-compliance [source].

TL;DR;

docker run --name postgresql bitnami/postgresql:latest

Docker Compose

version: '2'

services:
  postgresql:
    image: 'bitnami/postgresql:latest'
    ports:
      - '5432:5432'

Why use Bitnami Images ?

• Bitnami closely tracks upstream source changes and promptly publishes new versions of this image using our automated systems.
• With Bitnami images the latest bug fixes and features are available as soon as possible.
• Bitnami containers, virtual machines and cloud images use the same components and configuration approach - making it easy to switch between formats based on your project needs.
• Bitnami images are built on CircleCI and automatically pushed to the Docker Hub.
• All our images are based on minideb a minimalist Debian based container image which gives you a small base container image and the familiarity of a leading linux distribution.

Get this image

The recommended way to get the Bitnami PostgreSQL Docker Image is to pull the prebuilt image from the Docker Hub Registry.

docker pull bitnami/postgresql:latest

To use a specific version, you can pull a versioned tag. You can view the list of available versions in the Docker Hub Registry.

docker pull bitnami/postgresql:[TAG]

If you wish, you can also build the image yourself.

docker build -t bitnami/postgresql:latest https://github.com/bitnami/bitnami-docker-postgresql.git

Persisting your database

If you remove the container all your data and configurations will be lost, and the next time you run the image the database will be reinitialized. To avoid this loss of data, you should mount a volume that will persist even after the container is removed.

Note! If you have already started using your database, follow the steps on backing up and restoring to pull the data from your running container down to your host.

The image exposes a volume at /bitnami/postgresql for the PostgreSQL data and configurations. For persistence you can mount a directory at this location from your host. If the mounted directory is empty, it will be initialized on the first run.

docker run -v /path/to/postgresql-persistence:/bitnami/postgresql bitnami/postgresql:latest

or using Docker Compose:

version: '2'

services:
  postgresql:
    image: 'bitnami/postgresql:latest'
    ports:
      - '5432:5432'
    volumes:
      - /path/to/postgresql-persistence:/bitnami/postgresql

Connecting to other containers

Using Docker container networking, a PostgreSQL server running inside a container can easily be accessed by your application containers.

Containers attached to the same network can communicate with each other using the container name as the hostname.

Using the Command Line

In this example, we will create a PostgreSQL client instance that will connect to the server instance that is running on the same docker network as the client.

Step 1: Create a network

$ docker network create app-tier --driver bridge

Step 2: Launch the PostgreSQL server instance

Use the --network app-tier argument to the docker run command to attach the PostgreSQL container to the app-tier network.

$ docker run -d --name postgresql-server \
    --network app-tier \
    bitnami/postgresql:latest

Step 3: Launch your PostgreSQL client instance

Finally we create a new container instance to launch the PostgreSQL client and connect to the server created in the previous step:

$ docker run -it --rm \
    --network app-tier \
    bitnami/postgresql:latest psql -h postgresql-server -U postgres

Using Docker Compose

When not specified, Docker Compose automatically sets up a new network and attaches all deployed services to that network. However, we will explicitly define a new bridge network named app-tier. In this example we assume that you want to connect to the PostgreSQL server from your own custom application image which is identified in the following snippet by the service name myapp.

version: '2'

networks:
  app-tier:
    driver: bridge

services:
  postgresql:
    image: 'bitnami/postgresql:latest'
    networks:
      - app-tier
  myapp:
    image: 'YOUR_APPLICATION_IMAGE'
    networks:
      - app-tier

IMPORTANT:

1. Please update the YOUR_APPLICATION_IMAGE_ placeholder in the above snippet with your application image
2. In your application container, use the hostname postgresql to connect to the PostgreSQL server

Launch the containers using:

$ docker-compose up -d

Configuration

Setting the root password on first run

In the above commands you may have noticed the use of the POSTGRESQL_PASSWORD environment variable. Passing the POSTGRESQL_PASSWORD environment variable when running the image for the first time will set the password of the postgres user to the value of POSTGRESQL_PASSWORD.

docker run --name postgresql -e POSTGRESQL_PASSWORD=password123 bitnami/postgresql:latest

or using Docker Compose:

version: '2'

services:
  postgresql:
    image: 'bitnami/postgresql:latest'
    ports:
      - '5432:5432'
    environment:
      - POSTGRESQL_PASSWORD=password123

Note! The postgres user is a superuser and has full administrative access to the PostgreSQL database.

Creating a database on first run

By passing the POSTGRESQL_DATABASE environment variable when running the image for the first time, a database will be created. This is useful if your application requires that a database already exists, saving you from having to manually create the database using the PostgreSQL client.

docker run --name postgresql -e POSTGRESQL_DATABASE=my_database bitnami/postgresql:latest

or using Docker Compose:

version: '2'

services:
  postgresql:
    image: 'bitnami/postgresql:latest'
    ports:
      - '5432:5432'
    environment:
      - POSTGRESQL_DATABASE=my_database

Creating a database user on first run

You can also create a restricted database user that only has permissions for the database created with the POSTGRESQL_DATABASE environment variable. To do this, provide the POSTGRESQL_USERNAME environment variable.

docker run --name postgresql -e POSTGRESQL_USERNAME=my_user -e POSTGRESQL_PASSWORD=password123 -e POSTGRESQL_DATABASE=my_database bitnami/postgresql:latest

or using Docker Compose:

version: '2'

services:
  postgresql:
    image: 'bitnami/postgresql:latest'
    ports:
      - '5432:5432'
    environment:
      - POSTGRESQL_USERNAME=my_user
      - POSTGRESQL_PASSWORD=password123
      - POSTGRESQL_DATABASE=my_database

Note! When POSTGRESQL_USERNAME is specified, the postgres user is not assigned a password and as a result you cannot login remotely to the PostgreSQL server as the postgres user.

Setting up a streaming replication

A Streaming replication cluster can easily be setup with the Bitnami PostgreSQL Docker Image using the following environment variables:

• POSTGRESQL_REPLICATION_MODE: Replication mode. Possible values master/slave. No defaults.
• POSTGRESQL_REPLICATION_USER: The replication user created on the master on first run. No defaults.
• POSTGRESQL_REPLICATION_PASSWORD: The replication users password. No defaults.
• POSTGRESQL_MASTER_HOST: Hostname/IP of replication master (slave parameter). No defaults.
• POSTGRESQL_MASTER_PORT: Server port of the replication master (slave parameter). Defaults to 5432.

In a replication cluster you can have one master and zero or more slaves. When replication is enabled the master node is in read-write mode, while the slaves are in read-only mode. For best performance its advisable to limit the reads to the slaves.

Step 1: Create the replication master

The first step is to start the master.

docker run --name postgresql-master \
  -e POSTGRESQL_REPLICATION_MODE=master \
  -e POSTGRESQL_USERNAME=my_user \
  -e POSTGRESQL_PASSWORD=password123 \
  -e POSTGRESQL_DATABASE=my_database \
  -e POSTGRESQL_REPLICATION_USER=my_repl_user \
  -e POSTGRESQL_REPLICATION_PASSWORD=my_repl_password \
  bitnami/postgresql:latest

In this command we are configuring the container as the master using the POSTGRESQL_REPLICATION_MODE=master parameter. A replication user is specified using the POSTGRESQL_REPLICATION_USER and POSTGRESQL_REPLICATION_PASSWORD parameters.

Step 2: Create the replication slave

Next we start a replication slave container.

docker run --name postgresql-slave \
  --link postgresql-master:master \
  -e POSTGRESQL_REPLICATION_MODE=slave \
  -e POSTGRESQL_MASTER_HOST=master \
  -e POSTGRESQL_MASTER_PORT=5432 \
  -e POSTGRESQL_REPLICATION_USER=my_repl_user \
  -e POSTGRESQL_REPLICATION_PASSWORD=my_repl_password \
  bitnami/postgresql:latest

In the above command the container is configured as a slave using the POSTGRESQL_REPLICATION_MODE parameter. Before the replication slave is started, the POSTGRESQL_MASTER_HOST and POSTGRESQL_MASTER_PORT parameters are used by the slave container to connect to the master and replicate the initial database from the master. The POSTGRESQL_REPLICATION_USER and POSTGRESQL_REPLICATION_PASSWORD credentials are used to authenticate with the master.

With these two commands you now have a two node PostgreSQL master-slave streaming replication cluster up and running. You can scale the cluster by adding/removing slaves without incurring any downtime.

Note: The cluster replicates the master in its entirety, which includes all users and databases.

If the master goes down you can reconfigure a slave to act as the master and begin accepting writes by creating the trigger file /tmp/postgresql.trigger.5432. For example the following command reconfigures postgresql-slave to act as the master:

docker exec postgresql-slave touch /tmp/postgresql.trigger.5432

Note: The configuration of the other slaves in the cluster needs to be updated so that they are aware of the new master. This would require you to restart the other slaves with --link postgresql-slave:master as per our examples.

With Docker Compose the master-slave replication can be setup using:

version: '2'

services:
  postgresql-master:
    image: 'bitnami/postgresql:latest'
    ports:
      - '5432'
    volumes:
      - 'postgresql_master_data:/bitnami/postgresql'
    environment:
      - POSTGRESQL_REPLICATION_MODE=master
      - POSTGRESQL_REPLICATION_USER=repl_user
      - POSTGRESQL_REPLICATION_PASSWORD=repl_password
      - POSTGRESQL_USERNAME=my_user
      - POSTGRESQL_PASSWORD=my_password
      - POSTGRESQL_DATABASE=my_database
    volumes:
      - '/path/to/postgresql-persistence:/bitnami/postgresql'
  postgresql-slave:
    image: 'bitnami/postgresql:latest'
    ports:
      - '5432'
    depends_on:
      - postgresql-master
    environment:
      - POSTGRESQL_REPLICATION_MODE=slave
      - POSTGRESQL_REPLICATION_USER=repl_user
      - POSTGRESQL_REPLICATION_PASSWORD=repl_password
      - POSTGRESQL_MASTER_HOST=postgresql-master
      - POSTGRESQL_MASTER_PORT=5432

Scale the number of slaves using:

docker-compose scale postgresql-master=1 postgresql-slave=3

The above command scales up the number of slaves to 3. You can scale down in the same way.

Note: You should not scale up/down the number of master nodes. Always have only one master node running.

Configuration file

The image looks for configuration in the conf/ directory of /bitnami/postgresql. As as mentioned in Persisting your database you can mount a volume at this location and copy your own configurations in the conf/ directory. The default configuration will be copied to the conf/ directory if it's empty.

Step 1: Run the PostgreSQL image

Run the PostgreSQL image, mounting a directory from your host.

docker run --name postgresql -v /path/to/postgresql-persistence:/bitnami/postgresql bitnami/postgresql:latest

or using Docker Compose:

version: '2'

services:
  postgresql:
    image: 'bitnami/postgresql:latest'
    ports:
      - '5432:5432'
    volumes:
      - /path/to/postgresql-persistence:/bitnami/postgresql

Step 2: Edit the configuration

Edit the configuration on your host using your favorite editor.

vi /path/to/postgresql-persistence/conf/postgresql.conf

Step 3: Restart PostgreSQL

After changing the configuration, restart your PostgreSQL container for changes to take effect.

docker restart postgresql

or using Docker Compose:

docker-compose restart postgresql

Further Reading:

• Server Configuration

Logging

The Bitnami PostgreSQL Docker Image supports two different logging modes: logging to stdout, and logging to a file.

Logging to stdout

The default behavior is to log to stdout, as Docker expects. These will be collected by Docker, converted to JSON and stored in the host, to be accessible via the docker logs command.

docker logs postgresql

or using Docker Compose:

docker-compose logs postgresql

This method of logging has the downside of not being easy to manage. Without an easy way to rotate logs, they could grow exponentially and take up large amounts of disk space on your host.

Logging

The Bitnami PostgreSQL Docker image sends the container logs to the stdout. To view the logs:

docker logs postgresql

or using Docker Compose:

docker-compose logs postgresql

You can configure the containers logging driver using the --log-driver option if you wish to consume the container logs differently. In the default configuration docker uses the json-file driver.

Maintenance

Backing up your container

To backup your data, configuration and logs, follow these simple steps:

Step 1: Stop the currently running container

docker stop postgresql

or using Docker Compose:

docker-compose stop postgresql

Step 2: Run the backup command

We need to mount two volumes in a container we will use to create the backup: a directory on your host to store the backup in, and the volumes from the container we just stopped so we can access the data.

docker run --rm \
  -v /path/to/postgresql-backups:/backups \
  --volumes-from postgresql busybox \
  cp -a /bitnami/postgresql:latest /backups/latest

or using Docker Compose:

docker run --rm \
  -v /path/to/postgresql-backups:/backups \
  --volumes-from `docker-compose ps -q postgresql` busybox \
  cp -a /bitnami/postgresql:latest /backups/latest

Restoring a backup

Restoring a backup is as simple as mounting the backup as volumes in the container.

docker run \
  -v /path/to/postgresql-backups/latest:/bitnami/postgresql \
  bitnami/postgresql:latest

or using Docker Compose:

version: '2'

services:
  postgresql:
    image: 'bitnami/postgresql:latest'
    ports:
      - '5432:5432'
    volumes:
      - /path/to/postgresql-backups/latest:/bitnami/postgresql

Upgrade this image

Bitnami provides up-to-date versions of PostgreSQL, including security patches, soon after they are made upstream. We recommend that you follow these steps to upgrade your container.

Step 1: Get the updated image

docker pull bitnami/postgresql:latest

or if you're using Docker Compose, update the value of the image property to bitnami/postgresql:latest.

Step 2: Stop and backup the currently running container

Before continuing, you should backup your container's data, configuration and logs.

Follow the steps on creating a backup.

Step 3: Remove the currently running container

docker rm -v postgresql

or using Docker Compose:

docker-compose rm -v postgresql

Step 4: Run the new image

Re-create your container from the new image, restoring your backup if necessary.

docker run --name postgresql bitnami/postgresql:latest

or using Docker Compose:

docker-compose start postgresql

Testing

This image is tested for expected runtime behavior, using the BATS testing framework. You can run the tests on your machine using the bats command.

bats test.sh

Notable Changes

9.5.3-r5

• The POSTGRES_ prefix on environment variables is now replaced by POSTGRESQL_
• POSTGRES_USER parameter has been renamed to POSTGRESQL_USERNAME.
• POSTGRES_DB parameter has been renamed to POSTGRESQL_DATABASE.
• POSTGRES_MODE parameter has been renamed to POSTGRESQL_REPLICATION_MODE.

9.5.3-r0

• All volumes have been merged at /bitnami/postgresql. Now you only need to mount a single volume at /bitnami/postgresql for persistence.
• The logs are always sent to the stdout and are no longer collected in the volume.

Contributing

We'd love for you to contribute to this container. You can request new features by creating an issue, or submit a pull request with your contribution.

Issues

If you encountered a problem running this container, you can file an issue. For us to provide better support, be sure to include the following information in your issue:

• Host OS and version
• Docker version (docker version)
• Output of docker info
• Version of this container (echo $BITNAMI_IMAGE_VERSION inside the container)
• The command you used to run the container, and any relevant output you saw (masking any sensitive information)

Community

Most real time communication happens in the #containers channel at bitnami-oss.slack.com; you can sign up at slack.oss.bitnami.com.

Discussions are archived at bitnami-oss.slackarchive.io.

License

Copyright (c) 2015-2016 Bitnami

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.