container.md

title	order
Container	1

Container

Garden includes a container plugin, which provides:

• A Build action for Docker builds.
• Test and Run actions for running scripts or tests in one-off containers.
• A Deploy action that provides a simple way to define a Kubernetes Deployment, Service and Ingress in a single config.
  • Note: container-type Deploys are mostly intended to help users get up and running on Kubernetes quickly, and don't support the full range of configuration options for the underlying resources.
  • If you're already using Kubernetes in production, we strongly recommend using the Deploy actions of kubernetes or helm type instead.
  • This ensures you're developing and testing in a production-like environment, and lets you reuse your production manifests and charts during development and CI.

The plugin is built-in and doesn't require any configuration.

The corresponding container action type can be used to

• build container images
• deploy container-based applications
• run scripts inside deployed container-based applications
• run tests inside deployed container-based applications

Below we'll walk through some usage examples. For a full reference of the container action type, please take a look at the reference guides.

Note: Despite the container action types being mostly Kubernetes-oriented up to this point, we've tried to design this action type in a way that makes it generically deployable to other container orchestrators as well, such as Docker Swarm, AWS ECS etc.

Building images

Following is a bare minimum Build action using the container type:

# garden.yml
kind: Build
type: container
name: my-container

If you have a Dockerfile in the same directory as this file, this is enough to tell Garden to build it. However, you can override the Dockerfile name or path by specifying spec.dockerfile: <path-to-Dockerfile>. You might also want to explicitly include or exclude files in the build context.

Build arguments

You can specify build arguments using the spec.buildArgs field. This can be quite handy, especially when e.g. referencing other Build action as build dependencies:

# garden.yml
kind: Build
type: container
name: my-container
# Here, we ensure that the base image is built first. This is useful e.g. when you want to build a prod and a
# dev/testing variant of the image in your pipeline.
dependencies: [ build.base-image ]
spec:
  buildArgs:
    baseImageVersion: ${actions.build.base-image.version}

Additionally, Garden automatically sets GARDEN_ACTION_VERSION as a build argument, which you can use to reference the version of action being built. You use it internally as a Docker buildArg. For instance, to set versions, render docs, or clear caches.

Using remote images

If you're not building the container image yourself and just need to deploy an image that already exists in a registry, you need to specify the image in the Deploy action's spec:

# garden.yml
kind: Deploy
type: container
name: redis
spec:
  image: redis:5.0.5-alpine   # <- replace with any docker image ID

Publishing images

You can publish images that have been built in your cluster using the garden publish command.

Unless you're publishing to your configured deployment registry (when using the kubernetes provider), you need to specify the publishId field on the container action's spec in question to indicate where the image should be published. For example:

kind: Build
name: my-build
type: container
spec:
  publishId: my-repo/my-image:v1.2.3   # <- if you omit the tag here, the Garden action version will be used by default

By default, we use the tag specified in the container action's spec.publishId field. If none is set, we default to the corresponding Build action's version.

You can also set the --tag option on the garden publish command to override the tag used for images. You can both set a specific tag or you can use template strings for the tag. For example, you can

• Set a specific tag on all published builds: garden publish --tag "v1.2.3"
• Set a custom prefix on tags but include the Garden version hash: garden publish --tag 'v0.1-${build.hash}'
• Set a custom prefix on tags with the current git branch: garden publish --tag 'v0.1-${git.branch}'

{% hint style="warning" %} Note that you most likely need to wrap templated tags with single quotes, to prevent your shell from attempting to perform its own substitution. {% endhint %}

Generally, you can use any template strings available for action configs for the tags, with the addition of the following:

• ${build.name} — the name of the build being tagged
• ${build.version} — the full Garden version of the build being tagged, e.g. v-abcdef1234
• ${build.hash} — the Garden version hash of the build being tagged, e.g. abcdef1234 (i.e. without the v- prefix)

Deploying applications

After your application has been built, you probably also want to deploy it. For this, check out our guide on deploying to Kubernetes using container Deploy actions, or the kubernetes or helm type of Deploy actions for more advanced capabilities.

See the full spec of the Deploy action of container type in our reference docs.

Running tests

Test actions of container type run the command you specify in a one-off Kubernetes Pod, stream the logs and monitor for success or failure.

This is a great way to run tests in a standardized environment, especially integration tests, API tests or end-to-end tests (since Garden's ability to build, deploy and test in dependency order can easily be used to spin up the required components for a test suite before running it).

Here is a configuration example for two different test suites:

kind: Test
name: my-app-unit
type: container
build: my-app
spec:
  args: [ npm, test ]

---

kind: Test
name: my-app-integ
type: container
build: my-app
dependencies:
  - deploy.my-app
spec:
  args: [ npm, run, integ ]

Here we first define a unit test suite, which has no dependencies, and simply runs npm test in the my-app container.

The integ suite is similar but adds a runtime dependency. This means that before the integ test is run, Garden makes sure that my-app is running and up-to-date.

When you run garden test, we will run those tests. The tests will be executed by running the container with the specified command in your configured environment (as opposed to locally on the machine you're running the garden CLI from). Typically, this is a local or remote Kubernetes cluster—whatever you specify in your project configuration.

The names and commands to run are of course completely up to you, but we suggest naming the test suites consistently across your project's action configurations.

See the reference for all the configurable parameters for Test actions of container type.

Running arbitrary workloads

To run arbitrary workloads, you can use the Run actions. These can include any scripts or commands, and will be run within a container. The configuration is very similar to the Test actions:

kind: Run
type: container
name: db-migrate
dependencies: [ deploy.my-database ]
spec:
  command: [ rake, db:migrate ]

In this example, we define a db-migrate action that executes rake db:migrate (which is commonly used for database migrations in Ruby, but you can run anything you like of course). The action has a dependency on the my-database deployment, so that Garden will make sure the database is deployed before running the migration job.

One thing to note, is that Run actions should in most cases be idempotent, meaning that running the same Run action multiple times should be safe. This can be achieved by making sure that the script or tool your Run executes performs the relevant checks to decide if it should run (e.g. whether the DB exists and has the right schema already).

See the reference for all the configurable parameters for Run actions of container type.

Referencing from other actions

Since Garden version 0.13 any action (of any kind and type) can depend on any other action.

Actions can reference outputs from each other using template strings. For example, Build actions of container type are often referenced by Deploy actions of helm type:

kind: Deploy
description: Helm chart for the worker container
type: helm
name: my-app
spec:
  values:
    image:
      name: ${actions.build.my-image.outputs.deployment-image-name}
      tag: ${actions.build.my-image.version}

Here, we do not need to declare an explicit build dependency on my-image like dependencies: [ build.my-app ]. Instead, we do it implicitly via the references to the Build action outputs in spec.values.image.

For a full list of keys that are available for the container action type, take a look at the outputs reference of Build, Deploy, Run, and Test action kinds.

Mounting volumes and Kubernetes ConfigMaps

Volumes and ConfigMaps can be mounted in all Deploy, Run, and Test actions of the container type.

For mounting volumes, check out our guide on the persistentvolumeclaim action type, supported by the kubernetes provider.

And for ConfigMaps, check out this guide on the configmap action type, also supported by the kubernetes provider.