docker-compose Update Module

Integrate mender-docker-compose into the Yocto environment

Add the meta-mender-extended layer to your Yocto environment:

bitbake-layers add-layer ../sources/meta-mender/meta-mender-extended

You'll also need to add layers required for Docker support:

# Add required layers for Docker support
bitbake-layers add-layer ../sources/poky/meta-virtualization
bitbake-layers add-layer ../sources/meta-openembedded/meta-networking
bitbake-layers add-layer ../sources/meta-openembedded/meta-filesystems

Add the following to your local.conf to include mender-docker-compose in your build:

cat <<EOF >> conf/local.conf
# docker-compose Update Module

IMAGE_INSTALL:append = " mender-docker-compose"
DISTRO_FEATURES:append = " virtualization"
EOF

By default, Docker will store the container images in /var/lib/docker. In order for container images to persist over rootfs updates, it's necessary to configure Docker to use persistent storage. meta-mender provides a variable, MENDER_DOCKER_DATA_ROOT, which will set the Docker data-root in the /etc/docker/daemon.json config:

cat <<EOF >> conf/local.conf
MENDER_DOCKER_DATA_ROOT = "/data/docker"
EOF

Since we're now storing container images in the /data partition, it might be necessary to increase the storage sizes to ensure we don't run out of space during a docker-compose deployment, e.g.:

cat <<EOF >> conf/local.conf
MENDER_DATA_PART_SIZE_MB = "1024"
MENDER_STORAGE_TOTAL_SIZE_MB = "4096"
EOF

Next steps

For information on how to create docker-compose Artifacts, see Create a docker-compose update Artifact.