moby/experimental/docker-stacks.md

Docker Stacks

Overview

Docker Stacks are an experimental feature introduced in Docker 1.12, alongside the new concepts of Swarms and Services inside the Engine.

A Dockerfile can be built into an image, and containers can be created from that image. Similarly, a docker-compose.yml can be built into a bundle, and stacks can be created from that bundle. In that sense, the bundle is a multi-services distributable image format.

As of 1.12, the feature is introduced as experimental, and Docker Engine doesn't support distribution of bundles.

Producing a bundle

The easiest way to produce a bundle is to generate it using docker-compose from an existing docker-compose.yml. Of course, that's just one possible way to proceed, in the same way that docker build isn't the only way to produce a Docker image.

From docker-compose:

```bash
$ docker-compose bundle
WARNING: Unsupported key 'network_mode' in services.nsqd - ignoring
WARNING: Unsupported key 'links' in services.nsqd - ignoring
WARNING: Unsupported key 'volumes' in services.nsqd - ignoring
[...]
Wrote bundle to vossibility-stack.dsb
```

Creating a stack from a bundle

A stack is created using the docker deploy command:

```bash
# docker deploy --help

Usage:  docker deploy [OPTIONS] STACK

Create and update a stack

Options:
  -f, --bundle string   Path to a bundle (Default: STACK.dsb)
      --help            Print usage
```

Let's deploy the stack created before:

```bash
# docker deploy vossibility-stack
Loading bundle from vossibility-stack.dsb
Creating service vossibility-stack_elasticsearch
Creating service vossibility-stack_kibana
Creating service vossibility-stack_logstash
Creating service vossibility-stack_lookupd
Creating service vossibility-stack_nsqd
Creating service vossibility-stack_vossibility-collector
```

We can verify that services were correctly created:

```bash
# docker service ls
ID            NAME                                     SCALE  IMAGE
COMMAND
29bv0vnlm903  vossibility-stack_lookupd                1 nsqio/nsq@sha256:eeba05599f31eba418e96e71e0984c3dc96963ceb66924dd37a47bf7ce18a662 /nsqlookupd
4awt47624qwh  vossibility-stack_nsqd                   1 nsqio/nsq@sha256:eeba05599f31eba418e96e71e0984c3dc96963ceb66924dd37a47bf7ce18a662 /nsqd --data-path=/data --lookupd-tcp-address=lookupd:4160
4tjx9biia6fs  vossibility-stack_elasticsearch          1 elasticsearch@sha256:12ac7c6af55d001f71800b83ba91a04f716e58d82e748fa6e5a7359eed2301aa
7563uuzr9eys  vossibility-stack_kibana                 1 kibana@sha256:6995a2d25709a62694a937b8a529ff36da92ebee74bafd7bf00e6caf6db2eb03
9gc5m4met4he  vossibility-stack_logstash               1 logstash@sha256:2dc8bddd1bb4a5a34e8ebaf73749f6413c101b2edef6617f2f7713926d2141fe logstash -f /etc/logstash/conf.d/logstash.conf
axqh55ipl40h  vossibility-stack_vossibility-collector  1 icecrime/vossibility-collector@sha256:f03f2977203ba6253988c18d04061c5ec7aab46bca9dfd89a9a1fa4500989fba --config /config/config.toml --debug
```

Managing stacks

Tasks are managed using the docker stack command:

```bash
# docker stack --help

Usage:  docker stack COMMAND

Manage Docker stacks

Options:
      --help   Print usage

Commands:
  config      Print the stack configuration
  deploy      Create and update a stack
  rm          Remove the stack
  tasks       List the tasks in the stack

Run 'docker stack COMMAND --help' for more information on a command.
```