swarm-launcher

A docker image to allow the launch of container in docker swarm, with options normally unavailable to swarm mode

How it works

The image uses docker-compose to start a new project (see LAUNCH_PROJECT_NAME). You can either use the environment variables to configure the service started inside, or you can supply your own /docker-compose.yml file.

Either way, swarm-launcher takes care of the setup, tear-down and cleanup of the project.

Supported architectures

The following architectures are supported by this image:

• linux/amd64
• linux/arm64
• linux/arm/v7
• linux/arm/v6
• linux/386

Docs and Usage examples

See Docs and Usage Examples

Building the image

docker build -t swarm-launcher .

Environment variables

The following environment variables are important, if you plan on using a private repository:

Variable
LOGIN_USER
LOGIN_PASSWORD
LOGIN_PASSWORD_FILE
LOGIN_REGISTRY

The following environment variables are important if you don't supply a /docker-compose.yml file in the swarm-launcher container:

Variable	Default	Mandatory	Description
LAUNCH_IMAGE	-	YES	The image for the container
LAUNCH_PROJECT_NAME	random (by swarm-launcher)	NO	If you want to use a specific name for the project (similar to the stack name)
LAUNCH_SERVICE_NAME	random (by swarm-launcher)	NO	If you want to use a specific name for the service
LAUNCH_CONTAINER_NAME	random (by docker)	NO	If you want to use a specific name for the container (similar to the task name)
LAUNCH_HOSTNAME	-	NO	If you want to use a specific hostname for the container
LAUNCH_PRIVILEGED	false	NO	Set this to true if you want to start a privileged container
LAUNCH_DEVICES	-	NO	Space separated list of DeviceOnHost:DeviceInContainer
LAUNCH_VOLUMES	-	NO	Space separated list of File/FolderOnHost:File/FolderInContainer
LAUNCH_HOST_NETWORK	false	NO	Set this to true to start the container on the host network. This option is not compatible with LAUNCH_NETWORK_MODE, LAUNCH_PORTS, LAUNCH_NETWORKS, LAUNCH_EXT_NETWORKS and LAUNCH_EXT_NETWORKS_IPV4
LAUNCH_NETWORK_MODE	-	NO	Set this to a value that will be used as network_mode. This option is not compatible with LAUNCH_HOST_NETWORK, LAUNCH_PORTS, LAUNCH_NETWORKS, LAUNCH_EXT_NETWORKS and LAUNCH_EXT_NETWORKS_IPV4
LAUNCH_PORTS	-	NO	Space separated list of PortOnHost:PortInContainer
LAUNCH_NETWORKS	-	NO	Space separated list of project networks to create. All networks are created with attachable: true
LAUNCH_EXT_NETWORKS	-	NO	Space separated list of external networks to attach to
LAUNCH_EXT_NETWORKS_IPV4	-	NO	Similar to LAUNCH_EXT_NETWORKS, this is a space separated list of ExistingExternalNetworkName:Ipv4Address
LAUNCH_EXT_NETWORKS_IPV6	-	NO	Similar to LAUNCH_EXT_NETWORKS, this is a space separated list of ExistingExternalNetworkName-Ipv6Address
LAUNCH_EXT_NETWORKS_MIXED	-	NO	Similar to LAUNCH_EXT_NETWORKS, this is a space separated list of ExistingExternalNetworkName-Ipv4Address-Ipv6Address
LAUNCH_CAP_ADD	-	NO	Space separated list of capabilities to add
LAUNCH_CAP_DROP	-	NO	Space separated list of capabilities to drop
LAUNCH_SECURITY_OPT	-	NO	Space separated list of security options to add
LAUNCH_LABELS	ai.ix.started-by=ix.ai/swarm-launcher	NO	Space separated list of Label=Value pairs
LAUNCH_PULL	false	NO	Set this to true to check at every container start for the latest image version
LAUNCH_SYSCTLS	-	NO	Space separated list of sysctl=value
LAUNCH_SHM_SIZE	-	NO	Single value for the container SHM size. If omitted and not changed on a daemon level, all containers start with 67108864 (64 MB)
LAUNCH_COMMAND	-	NO	A string that overrides the default command
LAUNCH_CGROUP_PARENT	-	NO	A string that specify the parent cgroup for the container
LAUNCH_STOP_GRACE_PERIOD	10s (by docker)	NO	Allows to override the default stop_grace_period. Note: It makes sense to also add a slightly higher stop_grace_period to the swarm-launcher stack as well!
LAUNCH_PID_MODE	-	NO	Set this to host to enable PID address space sharing between container and host operating system
LAUNCH_ULIMITS	-	NO	Space separated list of Key=Value pairs. Note: Only integers are supported, NOT hard/soft ulimits! Example: nproc=131072 nofile=60000 core=0
LAUNCH_EXTRA_HOSTS	-	NO	Space separated list of HostName:Mapping pairs
LAUNCH_DNS	-	NO	Space separated list of DNS servers
LAUNCH_DNS_SEARCH	-	NO	Space separated list of DNS search domains
LAUNCH_MAC_ADDRESS	-	NO	Valid mac address for the launched container
LAUNCH_ENVIRONMENTS	-	NO	Space separated list of Key=Value pairs. Note: @_@ gets replaced with a single whitespace, so you can expose environment values containing spaces.
LAUNCH_ENVFILES	-	NO	Space separated list of Key=Value pairs. Note: These files must be present on the host where the container is started
LAUNCH_ARG_ENVFILE	-	NO	The path inside the swarm-launcher container with the env file used by docker compose --env-file XXX up

Note: Make sure you check out the documentation.

Resources

• GitLab: gitlab.com/ix.ai/swarm-launcher
• GitHub: github.com/ix-ai/swarm-launcher
• GitHub Registry: ghcr.io/ix-ai/swarm-launcher - ghcr.io/ix-ai/swarm-launcher
• Docker Hub: ixdotai/swarm-launcher - hub.docker.com/r/ixdotai/swarm-launcher

Credits

This Docker image is inspired by the post by @akomelj in moby/moby#25885