Compose Deploy Specification (original) (raw)

Deploy is an optional part of the Compose Specification. It provides a set of deployment specifications for managing the behavior of containers across different environments.

endpoint_mode

endpoint_mode specifies a service discovery method for external clients connecting to a service. The Compose Deploy Specification defines two canonical values:

• endpoint_mode: vip: Assigns the service a virtual IP (VIP) that acts as the front end for clients to reach the service on a network. Platform routes requests between the client and nodes running the service, without client knowledge of how many nodes are participating in the service or their IP addresses or ports.
• endpoint_mode: dnsrr: Platform sets up DNS entries for the service such that a DNS query for the service name returns a list of IP addresses (DNS round-robin), and the client connects directly to one of these.

labels

labels specifies metadata for the service. These labels are only set on the service and not on any containers for the service. This assumes the platform has some native concept of "service" that can match the Compose application model.

mode

mode defines the replication model used to run a service or job. Options include:

• global: Ensures exactly one task continuously runs per physical node until stopped.
• replicated: Continuously runs a specified number of tasks across nodes until stopped (default).
• replicated-job: Executes a defined number of tasks until a completion state (exits with code 0)'.
  • Total tasks are determined by replicas.
  • Concurrency can be limited using the max-concurrent option (CLI only).
• global-job: Executes one task per physical node with a completion state (exits with code 0).
  • Automatically runs on new nodes as they are added.

Note

• Job modes (replicated-job and global-job) are designed for tasks that complete and exit with code 0.
• Completed tasks remain until explicitly removed.
• Options like max-concurrent for controlling concurrency are supported only via the CLI and are not available in Compose.

For more detailed information about job options and behavior, see theDocker CLI documentation

placement

placement specifies constraints and preferences for the platform to select a physical node to run service containers.

constraints

constraints defines a required property the platform's node must fulfill to run the service container. For a further example, see theCLI reference docs.

preferences

preferences defines a strategy (currently spread is the only supported strategy) to spread tasks evenly over the values of the datacenter node label. For a further example, see theCLI reference docs

replicas

If the service is replicated (which is the default), replicas specifies the number of containers that should be running at any given time.

resources

resources configures physical resource constraints for container to run on platform. Those constraints can be configured as:

• limits: The platform must prevent the container to allocate more.
• reservations: The platform must guarantee the container can allocate at least the configured amount.

cpus

cpus configures a limit or reservation for how much of the available CPU resources, as number of cores, a container can use.

memory

memory configures a limit or reservation on the amount of memory a container can allocate, set as a string expressing abyte value.

pids

pids tunes a container’s PIDs limit, set as an integer.

devices

devices configures reservations of the devices a container can use. It contains a list of reservations, each set as an object with the following parameters: capabilities, driver, count, device_ids and options.

Devices are reserved using a list of capabilities, making capabilities the only required field. A device must satisfy all the requested capabilities for a successful reservation.

capabilities

capabilities are set as a list of strings, expressing both generic and driver specific capabilities. The following generic capabilities are recognized today:

• gpu: Graphics accelerator
• tpu: AI accelerator

To avoid name clashes, driver specific capabilities must be prefixed with the driver name. For example, reserving an NVIDIA CUDA-enabled accelerator might look like this:

driver

A different driver for the reserved device(s) can be requested using driver field. The value is specified as a string.

count

If count is set to all or not specified, Compose reserves all devices that satisfy the requested capabilities. Otherwise, Compose reserves at least the number of devices specified. The value is specified as an integer.

count and device_ids fields are exclusive. Compose returns an error if both are specified.

device_ids

If device_ids is set, Compose reserves devices with the specified IDs provided they satisfy the requested capabilities. The value is specified as a list of strings.

count and device_ids fields are exclusive. Compose returns an error if both are specified.

options

Driver specific options can be set with options as key-value pairs.

restart_policy

restart_policy configures if and how to restart containers when they exit. If restart_policy is not set, Compose considers the restart field set by the service configuration.

• condition. When set to:
  • none, containers are not automatically restarted regardless of the exit status.
  • on-failure, the container is restarted if it exits due to an error, which manifests as a non-zero exit code.
  • any (default), containers are restarted regardless of the exit status.
• delay: How long to wait between restart attempts, specified as aduration. The default is 0, meaning restart attempts can occur immediately.
• max_attempts: The maximum number of failed restart attempts allowed before giving up. (Default: unlimited retries.) A failed attempt only counts toward max_attempts if the container does not successfully restart within the time defined by window. For example, if max_attempts is set to 2 and the container fails to restart within the window on the first try, Compose continues retrying until two such failed attempts occur, even if that means trying more than twice.
• window: The amount of time to wait after a restart to determine whether it was successful, specified as aduration (default: the result is evaluated immediately after the restart).

rollback_config

rollback_config configures how the service should be rollbacked in case of a failing update.

• parallelism: The number of containers to rollback at a time. If set to 0, all containers rollback simultaneously.
• delay: The time to wait between each container group's rollback (default 0s).
• failure_action: What to do if a rollback fails. One of continue or pause (default pause)
• monitor: Duration after each task update to monitor for failure (ns|us|ms|s|m|h) (default 0s).
• max_failure_ratio: Failure rate to tolerate during a rollback (default 0).
• order: Order of operations during rollbacks. One of stop-first (old task is stopped before starting new one), or start-first (new task is started first, and the running tasks briefly overlap) (default stop-first).

update_config

update_config configures how the service should be updated. Useful for configuring rolling updates.

• parallelism: The number of containers to update at a time.
• delay: The time to wait between updating a group of containers.
• failure_action: What to do if an update fails. One of continue, rollback, or pause (default: pause).
• monitor: Duration after each task update to monitor for failure (ns|us|ms|s|m|h) (default 0s).
• max_failure_ratio: Failure rate to tolerate during an update.
• order: Order of operations during updates. One of stop-first (old task is stopped before starting new one), or start-first (new task is started first, and the running tasks briefly overlap) (default stop-first).