How to test ZFS and sysv IPC annotations¶

for a detailed explanation you can refer to Dave Cottlehuber's tutorial
for an extremely complete overview of all aspects of running containers on Freebsd you can refer to Dave Cottlehuber's documentation page
all praise and thanks be heaped on Doug Rabson, Samuel Karp and Alice Sowerby for their work

Activate OCI hooks¶

Make sure /usr/local/etc/containers/containers.conf specifies the path to at least one OCI hooks directory and that it is not commented, e.g.:

hooks_dir = [
  "/usr/local/etc/containers/hooks.d",
]

# execute as root
mkdir -p /usr/local/etc/containers/hooks.d/

Add hooks¶

0. Clone the repo¶

git clone git@github.com:matias-pizarro/freebsd-oci-containers.git
cd freebsd-oci-containers

1. To mount persistent ZFS datasets in any given container¶

# execute as root
cp -pf annotations/hooks.d/zfs* /usr/local/etc/containers/hooks.d/

2. To enable sysv IPC in any given container¶

# execute as root
cp -pf annotations/hooks.d/sysv* /usr/local/etc/containers/hooks.d/

Test with a PostgreSQL container¶

1. Create a persistent ZFS dataset¶

# execute as root
zfs create -p \
    -o jailed=on \
    -o mountpoint=/var/db/postgres \
zroot/jailed/postgres

2. Initialize a PostgreSQL instance¶

(You can find the Containerfile used to build this image here)

# pg_major can be any major PostgreSQL version between 13 and 18 (included)
export pg_major=18
export postgres_image="ghcr.io/matias-pizarro/freebsd-oci-containers/freebsd-postgres${pg_major}:14.3"

podman run -it --rm \
    --annotation='sysv=true' \
    --annotation='zfs.dataset=zroot/jailed/postgres' \
    --env POSTGRES_PASSWORD=password \
    ${postgres_image} \
    chown -R 770:770 /var/db/postgres

podman run -it --rm \
    --annotation='sysv=true' \
    --annotation='zfs.dataset=zroot/jailed/postgres' \
    --env POSTGRES_PASSWORD=password \
    ${postgres_image} \
    service postgresql initdb

3. Run a PostgreSQL server instance¶

This instance will be available for connections from the host via a socket at /tmp/postgresql${pg_major}

podman run -it --rm \
    --annotation='sysv=true' \
    --volume /tmp/postgresql${pg_major}:/var/run/postgresql \
    --env POSTGRES_PASSWORD=password \
    ${postgres_image} \
        postgres -D /var/db/postgres/data${pg_major} \
            -c logging_collector=true \
            -c log_filename=postgres.log \
            -c log_destination=jsonlog \
            -k /var/run/postgresql

You can now connect to the server from another command line:

export pg_major=18
psql -h /tmp/postgresql${pg_major} -U postgres