> This PostgreSQL cluster solution includes the PostgreSQL replication manager, an open-source tool for managing replication and failover on PostgreSQL clusters.
[Overview of PostgreSQL HA](https://www.postgresql.org)
## Using a Docker Compose file
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 `my-network`. 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`.
```yaml
version: '2'
networks:
my-network:
driver: bridge
services:
pg-0:
image: bitnami/postgresql-repmgr:latest
networks:
- my-network
environment:
- POSTGRESQL_PASSWORD=custompassword
- REPMGR_PASSWORD=repmgrpassword
- REPMGR_PRIMARY_HOST=pg-0
- REPMGR_NODE_NETWORK_NAME=pg-0
- REPMGR_NODE_NAME=pg-0
- REPMGR_PARTNER_NODES=pg-0
myapp:
image: YOUR_APPLICATION_IMAGE
networks:
- my-network
```
> **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 `pg-0` to connect to the PostgreSQL server
## Configuration
### Initializing a new instance
When the container is executed for the first time, it will execute the files with extensions `.sh`, `.sql` and `.sql.gz` located at `/docker-entrypoint-initdb.d`.
In order to have your custom files inside the docker image you can mount them as a volume.
### Setting the root and repmgr passwords on first run
In the above commands you may have noticed the use of the `POSTGRESQL_PASSWORD` and `REPMGR_PASSWORD` environment variables. 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` (or the content of the file specified in `POSTGRESQL_PASSWORD_FILE`). In the same way, passing the `REPMGR_PASSWORD` environment variable sets the password of the `repmgr` user to the value of `REPMGR_PASSWORD` (or the content of the file specified in `REPMGR_PASSWORD_FILE`).
```console
docker run --name pg-0 --env REPMGR_PASSWORD=repmgrpass --env POSTGRESQL_PASSWORD=secretpass bitnami/postgresql-repmgr:latest
```
or by modifying the [`docker-compose.yml`](https://github.com/bitnami/containers/tree/main/bitnami/postgresql-repmgr/docker-compose.yml) file present in this repository:
```diff
...
services:
pg-0:
...
environment:
- - POSTGRESQL_PASSWORD=adminpassword
+ - POSTGRESQL_PASSWORD=password123
- - REPMGR_PASSWORD=repmgrpassword
+ - REPMGR_PASSWORD=password123
...
pg-1:
...
environment:
- - POSTGRESQL_PASSWORD=adminpassword
+ - POSTGRESQL_PASSWORD=password123
- - REPMGR_PASSWORD=repmgrpassword
+ - REPMGR_PASSWORD=password123
...
```
**Note!**
Both `postgres` and `repmgr` users are superusers and have full administrative access to the PostgreSQL database.
Refer to [Creating a database user on first run](#creating-a-database-user-on-first-run) if you want to set an unprivileged user and a password for the `postgres` user.
### 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.
```console
docker run --name pg-0 --env POSTGRESQL_DATABASE=my_database bitnami/postgresql-repmgr:latest
```
### 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`](#creating-a-database-on-first-run) environment variable. To do this, provide the `POSTGRESQL_USERNAME` environment variable.
The [`docker-compose.yml`](https://github.com/bitnami/containers/tree/main/bitnami/postgresql/docker-compose.yml) file present in this repository already configures this setup.
**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. If you still want to have access with the user `postgres`, please set the `POSTGRESQL_POSTGRES_PASSWORD` environment variable (or the content of the file specified in `POSTGRESQL_POSTGRES_PASSWORD_FILE`).
### Setting up a HA PostgreSQL cluster with streaming replication and repmgr
A HA PostgreSQL cluster with [Streaming replication](https://www.postgresql.orgdocs/10/warm-standby.html#STREAMING-REPLICATION) and [repmgr](https://repmgr.org) can easily be setup with the Bitnami PostgreSQL HA Docker Image using the following environment variables:
-`POSTGRESQL_PASSWORD`: Password for `postgres` user. No defaults.
-`POSTGRESQL_PASSWORD_FILE`: Path to a file that contains the `postgres` user password. This will override the value specified in `POSTGRESQL_PASSWORD`. No defaults.
-`REPMGR_USERNAME`: Username for `repmgr` user. Defaults to `repmgr`.
-`REPMGR_PASSWORD_FILE`: Path to a file that contains the `repmgr` user password. This will override the value specified in `REPMGR_PASSWORD`. No defaults.
-`REPMGR_PASSWORD`: Password for `repmgr` user. No defaults.
-`REPMGR_USE_PASSFILE`: Configure repmgr to use `passfile` and `PGPASSFILE` instead of plain-text password in its configuration.
-`REPMGR_PASSFILE_PATH`: Location of the passfile, if it doesn't exist it will be created using REPMGR credentials.
-`REPMGR_PRIMARY_HOST`: Hostname of the initial primary node. No defaults.
-`REPMGR_PARTNER_NODES`: Comma separated list of partner nodes in the cluster. No defaults.
-`REPMGR_NODE_NAME`: Node name. No defaults.
-`REPMGR_NODE_TYPE`: Node type. Defaults to `data`. Allowed values: `data` for data nodes (master or replicas), `witness` for witness nodes.
-`REPMGR_NODE_NETWORK_NAME`: Node hostname. No defaults.
-`REPMGR_PGHBA_TRUST_ALL`: This will set the auth-method in the generated pg_hba.conf. Set it to `yes` only if you are using pgpool with LDAP authentication. Default to `no`.
In a HA PostgreSQL cluster you can have one primary and zero or more standby nodes. The primary node is in read-write mode, while the standby nodes are in read-only mode. For best performance its advisable to limit the reads to the standby nodes.
> NOTE: REPMGR_USE_PASSFILE and REPMGR_PASSFILE_PATH will be ignored for Postgresql prior to version 9.6.
>
> When mounting an external passfile using REPMGR_PASSFILE_PATH, it is necessary to also configure REPMGR_PASSWORD and REPMGR_USERNAME accordingly.
#### Step 1: Create a network and the initial primary node
The first step is to start the initial primary node:
```console
docker network create my-network --driver bridge
docker run --detach --name pg-0 \
--network my-network \
--env REPMGR_PARTNER_NODES=pg-0,pg-1 \
--env REPMGR_NODE_NAME=pg-0 \
--env REPMGR_NODE_NETWORK_NAME=pg-0 \
--env REPMGR_PRIMARY_HOST=pg-0 \
--env REPMGR_PASSWORD=repmgrpass \
--env POSTGRESQL_PASSWORD=secretpass \
bitnami/postgresql-repmgr:latest
```
#### Step 2: Create a standby node
Next we start a standby node:
```console
docker run --detach --name pg-1 \
--network my-network \
--env REPMGR_PARTNER_NODES=pg-0,pg-1 \
--env REPMGR_NODE_NAME=pg-1 \
--env REPMGR_NODE_NETWORK_NAME=pg-1 \
--env REPMGR_PRIMARY_HOST=pg-0 \
--env REPMGR_PASSWORD=repmgrpass \
--env POSTGRESQL_PASSWORD=secretpass \
bitnami/postgresql-repmgr:latest
```
With these three commands you now have a two node PostgreSQL primary-standby streaming replication cluster up and running. You can scale the cluster by adding/removing standby nodes without incurring any downtime.
> **Note**: The cluster replicates the primary in its entirety, which includes all users and databases.
If the master goes down, **repmgr** will ensure any of the standby nodes takes the primary role, guaranteeing high availability.
> **Note**: The configuration of the other nodes in the cluster needs to be updated so that they are aware of them. This would require you to restart the old nodes adapting the `REPMGR_PARTNER_NODES` environment variable.
With Docker Compose the HA PostgreSQL cluster can be setup using the [`docker-compose.yml`](https://github.com/bitnami/containers/tree/main/bitnami/postgresql-repmgr/docker-compose.yml) file present in this repository:
PostgreSQL supports the encryption of connections using the SSL/TLS protocol. Should you desire to enable this optional feature, you may use the following environment variables to configure the application:
-`POSTGRESQL_ENABLE_TLS`: Whether to enable TLS for traffic or not. Defaults to `no`.
-`POSTGRESQL_TLS_CERT_FILE`: File containing the certificate file for the TLS traffic. No defaults.
-`POSTGRESQL_TLS_KEY_FILE`: File containing the key for certificate. No defaults.
-`POSTGRESQL_TLS_CA_FILE`: File containing the CA of the certificate. If provided, PostgreSQL will authenticate TLS/SSL clients by requesting them a certificate (see [ref](https://www.postgresql.orgdocs/9.6/auth-methods.html)). No defaults.
-`POSTGRESQL_TLS_CRL_FILE`: File containing a Certificate Revocation List. No defaults.
-`POSTGRESQL_TLS_PREFER_SERVER_CIPHERS`: Whether to use the server's TLS cipher preferences rather than the client's. Defaults to `yes`.
When enabling TLS, PostgreSQL will support both standard and encrypted traffic by default, but prefer the latter. Below there are some examples on how to quickly set up TLS traffic:
Alternatively, you may also provide this configuration in your [custom](https://github.com/bitnami/containers/tree/main/bitnami/postgresql-repmgr) configuration file.
### Configuration file
The image looks for the `repmgr.conf`, `postgresql.conf` and `pg_hba.conf` files in `/opt/bitnami/repmgr/conf/` and `/opt/bitnami/postgresql/conf/`. You can mount a volume at `/bitnami/repmgr/conf/` and copy/edit the configuration files in the `/path/to/custom-conf/`. The default configurations will be populated to the `conf/` directories if `/bitnami/repmgr/conf/` is empty.
```console
/path/to/custom-conf/
└── postgresql.conf
```
As the PostgreSQL with Replication manager image is non-root, you need to set the proper permissions to the mounted directory in your host:
```console
sudo chgrp -R root /path/to/custom-conf/
sudo chmod -R g+rwX /path/to/custom-conf/
```
#### Step 1: Run the PostgreSQL image
Run the PostgreSQL image, mounting a directory from your host.
```console
docker run --name pg-0 \
-v /path/to/custom-conf/:/bitnami/repmgr/conf/ \
bitnami/postgresql-repmgr:latest
```
or using Docker Compose:
```yaml
version: '2'
services:
pg-0:
image: bitnami/postgresql-repmgr:latest
ports:
- 5432:5432
volumes:
- /path/to/custom-conf/:/bitnami/repmgr/conf/
pg-1:
image: bitnami/postgresql-repmgr:latest
ports:
- 5432:5432
volumes:
- /path/to/custom-conf/:/bitnami/repmgr/conf/
```
#### Step 2: Edit the configuration
Edit the configuration on your host using your favorite editor.
```console
vi /path/to/custom-conf/postgresql.conf
```
#### Step 3: Restart PostgreSQL
After changing the configuration, restart your PostgreSQL container for changes to take effect.
```console
docker restart pg-0
```
or using Docker Compose:
```console
docker-compose restart pg-0
docker-compose restart pg-1
```
Refer to the [server configuration](http://www.postgresql.org/docs/10/static/runtime-config.html) manual for the complete list of configuration options.
#### Allow settings to be loaded from files other than the default `postgresql.conf`
Apart of using a custom `repmgr.conf`, `postgresql.conf` or `pg_hba.conf`, you can include files ending in `.conf` from the `conf.d` directory in the volume at `/bitnami/postgresql/conf/`.
For this purpose, the default `postgresql.conf` contains the following section:
## These options allow settings to be loaded from files other than the
## default postgresql.conf.
include_dir = 'conf.d' # Include files ending in '.conf' from directory 'conf.d'
```
If you are using your custom `postgresql.conf`, you should create (or uncomment) the above section in your config file, in this case the structure should be something like
```console
/path/to/custom-conf/
└── postgresql.conf
/path/to/extra-custom-conf/
└── extended.conf
```
Remember to set the proper permissions to the mounted directory in your host:
```console
sudo chgrp -R root /path/to/extra-custom-conf/
sudo chmod -R g+rwX /path/to/extra-custom-conf/
```
#### Step 1: Deploy the PostgreSQL image
Run the PostgreSQL image, mounting a directory from your host.
Edit the configuration on your host using your favorite editor.
```console
vi /path/to/extra-custom-conf/extended.conf
```
#### Step 3: Restart the PostgreSQL container
After changing the configuration, restart your PostgreSQL container for changes to take effect.
```console
docker restart pg-0
```
or using Docker Compose:
```console
docker-compose restart pg-0
docker-compose restart pg-1
```
### Adding extra services to base docker-compose.yaml
It is possible to add extra services to the provided `docker-compose.yaml` file, like [a witness node](https://repmgr.org/docs/4.3/repmgrd-witness-server.html). When adding the new service, please take into account the cluster set up process relays on the `REPMGR_NODE_ID_START_SEED` environment variable plus the service ID in the name (if present, or zero (`0`) by default) to assign cluster's ID to each service/node involved on it. In the case of docker-compose based clusters, this may lead to collisions in the internal IDs in case two or more services share the same ID in their names, making the service initialization process to fail. This isn't an issue on Kubernetes environments, as the Kubernetes controller enumerates the pods with different ID numbers by default.
We recommend setting a different value for the `REPMGR_NODE_ID_START_SEED` in those nodes, or ensuring no services names use repeated numbers. Find below a sample service for a witness service:
| `POSTGRESQL_MASTER_PORT_NUMBER` | PostgreSQL master host port | `$REPMGR_PRIMARY_PORT` |
### FIPS configuration in Bitnami Secure Images
The Bitnami PostgreSQL HA Docker image from the [Bitnami Secure Images](https://go-vmware.broadcom.com/contact-us) catalog includes extra features and settings to configure the container with FIPS capabilities. You can configure the next environment variables:
-`OPENSSL_FIPS`: whether OpenSSL runs in FIPS mode or not. `yes` (default), `no`.
## Logging
The Bitnami PostgreSQL HA Docker image sends the container logs to `stdout`. To view the logs:
```console
docker logs pg-0
```
You can configure the containers [logging driver](https://docs.docker.com/engine/admin/logging/overview/) using the `--log-driver` option if you wish to consume the container logs differently. In the default configuration docker uses the `json-file` driver.
## Maintenance
### Upgrade this image
Bitnami provides up-to-date versions of PostgreSQL HA, including security patches, soon after they are made upstream. We recommend that you follow these steps to upgrade your container.
#### Step 1: Get the updated image
```console
docker pull bitnami/postgresql-repmgr:latest
```
or if you're using Docker Compose, update the value of the image property to `bitnami/postgresql-repmgr:latest`.
#### Step 2: Stop the running container
Stop the currently running container using the command
```console
docker stop pg-0
```
or using Docker Compose:
```console
docker-compose stop pg-0
docker-compose stop pg-1
```
Next, take a snapshot of the persistent volume `/path/to/postgresql-persistence` using:
```console
rsync -a /path/to/postgresql-persistence /path/to/postgresql-persistence.bkp.$(date +%Y%m%d-%H.%M.%S)
```
#### Step 3: Remove the currently running container
```console
docker rm -v pg-0
```
or using Docker Compose:
```console
docker-compose rm -v pg-0
docker-compose rm -v pg-1
```
#### Step 4: Run the new image
Re-create your container from the new image.
```console
docker run --name pg-0 bitnami/postgresql-repmgr:latest
```
or using Docker Compose:
```console
docker-compose up pg-0
docker-compose up pg-1
```
## Notable Changes
### 9.6.16-centos-7-r71, 10.11.0-centos-7-r71, 11.6.0-centos-7-r67, and 12.1.0-centos-7-r67
-`9.6.16-centos-7-r71`, `10.11.0-centos-7-r71`, `11.6.0-centos-7-r67`, and `12.1.0-centos-7-r67` are considered the latest images based on CentOS.
- Adds Postgis extension to postgresql, version 2.3.x to Postgresiql 9.6 and version 2.5 to 10, 11 and 12.
## Using `docker-compose.yaml`
Please be aware this file has not undergone internal testing. Consequently, we advise its use exclusively for development or testing purposes. For production-ready deployments, we highly recommend utilizing its associated [Bitnami Helm chart](https://github.com/bitnami/charts/tree/main/bitnami/postgresql-ha).
If you detect any issue in the `docker-compose.yaml` file, feel free to report it or contribute with a fix by following our [Contributing Guidelines](https://github.com/bitnami/containers/blob/main/CONTRIBUTING.md).