Postgres: Backup and restore scripts.

FROM docker.io/postgres:16.1-alpine3.19

COPY --chown=root:root healthcheck /usr/local/bin/

COPY --chown=root:root healthcheck backup restore /usr/local/bin/

HEALTHCHECK --start-period=3m CMD healthcheck

# postgres

Just the upstream image but with a healthcheck.

## Backups

The image includes a `backup` and `restore` scripts. The `backup` scripts dumps

all of the databases using `pg_dumpall` and compresses the output using `zstd`

to stdout. This is meant so that backups are run by an external process and it

saves the output to a file, for example:

```

docker exec pg1 backup > /var/backups/pg1/dump.sql.zstd

```

The `restore` script matches the `backup` script in that the it reads a zstd

compress SQL dump from stdin. An example restore:

```

cat dump.sql.zstd | docker exec -i pg2 restore

```

In fact you're able to migrate data from 1 instance to another like so:

```

docker exec pg1 backup | docker exec -i pg2 restore

```

#!/usr/bin/env bash

set -euo pipefail

export PGUSER="${POSTGRES_USER:-postgres}"

pg_dumpall | zstd

#!/usr/bin/env bash

set -euo pipefail

export PGUSER="${POSTGRES_USER:-postgres}"

zstd --decompress - | psql