ethoslink/postgres-backrest repository overview

⁠Postgres + PgBackRest

A production-ready PostgreSQL image with PgBackRest preinstalled and sensible default configuration.

This image is maintained by Ethos Link⁠. It is a small, reusable extract from operational work we do for Reviato⁠, a review intelligence product built by Ethos Link.

The goal is simple: make it easy to run Postgres with backups and predictable configuration without turning your repo into an ops research project.

⁠About

We believe in open source and sharing operational knowledge. If you like this project, see:

• git-markdown⁠: A tool to convert git repos into LLM-friendly markdown.
• Reviato⁠: Intelligent review management for automated businesses.

⁠What you get

• PostgreSQL + PgBackRest in one image (based on the upstream postgres image)
• WAL archiving-ready defaults (pair this with a PgBackRest repo config)
• Bring-your-own postgresql.conf (pgtune-friendly) via a mounted file
• Drop-in overrides via /etc/postgresql/conf.d/*.conf (optional)
• Multi-arch support (amd64, arm64)

⁠Quickstart

docker run \
 -e POSTGRES_PASSWORD=mysecretpassword \
 ethoslink/postgres-backrest:latest

⁠Configuration

⁠PostgreSQL Configuration

The image ships with a default /etc/postgresql/postgresql.conf.

For anything beyond a couple of settings, the recommended practice is to provide a real Postgres config file (for example one generated by https://pgtune.leopard.in.ua⁠) and mount it into the container.

⁠Option A (simplest): replace the default config

1. Generate a config on pgtune.
2. Save it as postgresql.conf.
3. Mount it to /etc/postgresql/postgresql.conf.

Example (docker run):

docker run \
 -e POSTGRES_PASSWORD=mysecretpassword \
 -v "$PWD/postgresql.conf:/etc/postgresql/postgresql.conf:ro" \
 ethoslink/postgres-backrest:latest

⁠Option B: mount the config elsewhere and point Postgres at it

Set POSTGRES_CONFIG_FILE to the file you mounted:

docker run \
 -e POSTGRES_PASSWORD=mysecretpassword \
 -e POSTGRES_CONFIG_FILE=/etc/postgresql/pgtune/postgresql.conf \
 -v "$PWD/postgresql.conf:/etc/postgresql/pgtune/postgresql.conf:ro" \
 ethoslink/postgres-backrest:latest

⁠Option C: mount small overrides (recommended when you only need a couple of changes)

The shipped postgresql.conf includes include_dir = 'conf.d', so you can mount a small snippet without replacing the full file:

docker run \
 -e POSTGRES_PASSWORD=mysecretpassword \
 -v "$PWD/overrides.conf:/etc/postgresql/conf.d/overrides.conf:ro" \
 ethoslink/postgres-backrest:latest

⁠Notes

• PostgreSQL doesn't provide a standardized set of environment variables for tuning knobs like shared_buffers, work_mem, effective_cache_size, etc. The established approach is to manage postgresql.conf (and optionally conf.d snippets) as configuration artifacts.
• If you use container memory limits, treat pgtune output as a baseline and validate values against your runtime limits.

⁠Extra knobs supported by this image

• POSTGRES_CONFIG_FILE (default: /etc/postgresql/postgresql.conf)
• POSTGRES_HBA_FILE (default: /etc/postgresql/pg_hba.conf)

These are used to inject -c config_file=... and -c hba_file=... when the container is started with the postgres command.

⁠PgBackRest Configuration

On startup, the container renders /etc/pgbackrest/pgbackrest.conf from the template at /usr/local/share/pgbackrest/pgbackrest.conf.template using envsubst.

The default template is intentionally minimal and local-by-default. To customize PgBackRest behavior (including S3/R2/backends, retention, compression, etc.), provide your own template by mounting it into the container at:

• /usr/local/share/pgbackrest/pgbackrest.conf.template

See the shipped template in this repo at postgres-backrest/pgbackrest.conf.template.

Common env vars referenced by the default template:

• PGBACKREST_REPO1_PATH
• PGBACKREST_REPO1_RETENTION_FULL
• PGBACKREST_REPO1_RETENTION_DIFF
• PGBACKREST_PROCESS_MAX
• PGBACKREST_LOG_LEVEL_CONSOLE
• PGBACKREST_LOG_LEVEL_FILE
• PGBACKREST_LOG_PATH
• PGBACKREST_COMPRESS_TYPE
• PGBACKREST_COMPRESS_LEVEL
• PGBACKREST_PG1_PATH

⁠Building

To build the image with a specific PostgreSQL version:

docker build --build-arg POSTGRES_VERSION=18.1 -t ethoslink/postgres-backrest:18.1 .

⁠Security & Maintenance

The image is based on the official Debian-based PostgreSQL image and installs pgbackrest from the official apt repositories.

• Updates: Images are immutable. To get security updates, pull a newer tag.
• Scanning: We run Trivy⁠ scans on every build to monitor for vulnerabilities.

⁠Publishing

The image is published to:

• Docker Hub: ethoslink/postgres-backrest
• GitHub Container Registry: ghcr.io/ethos-link/postgres-backrest

To update to a new PostgreSQL version, pass a different POSTGRES_VERSION build-arg (or change the Dockerfile default) and rebuild.

⁠License

MIT