Innerloop versus outerloop

In a devfile spec, there are two scopes of deployment: innerloop and outerloop. Having these scopes is essential for a full development experience as well as ensuring proper integration of the full scope of development tools for Kubernetes and OpenShift projects.

Prerequisites

What is innerloop?

Innerloop deployments are actions the developer makes within their development environment, such as running tests, debugging, and local deployments before checking into the target source repository.

Procedure

Add the runtime container component for running your project with the schemaVersion and metadata definitions

This example will use nodejs-18 UBI image

schemaVersion: 2.2.2
metadata:
  name: nodejs
components:
  - name: runtime
    container:
      image: registry.access.redhat.com/ubi8/nodejs-18:latest
      args: ['tail', '-f', '/dev/null']
      memoryLimit: 1024Mi
      mountSources: true

If your project needs ports to be forwarded like in this example, define the endpoints required for your project

Note: If you are using odo v3, you need to create an additional endpoint for the debugging port. See Odo Spec Support for more information
The environment variable definition DEBUG_PORT is to set the debug port of the node application

components:
  - name: runtime
    container:
      image: registry.access.redhat.com/ubi8/nodejs-18:latest
      args: ['tail', '-f', '/dev/null']
      memoryLimit: 1024Mi
      mountSources: true
      env:
        - name: DEBUG_PORT
          value: '5858'
      endpoints:
        - name: http-node
          targetPort: 3000
        - exposure: none
          name: debug
          targetPort: 5858

Now the runtime component has been defined, we need a way of running our project

Add a command to npm install our project packages and mark it as our projects build command
Add another command to run the main process or the server process npm start in this example and mark it as our projects run command
With these commands you should now be able to run a development deployment of your project, for example odo dev

commands:
  - id: install
    exec:
      component: runtime
      commandLine: npm install
      workingDir: ${PROJECT_SOURCE}
      group:
        kind: build
        isDefault: true
  - id: run
    exec:
      component: runtime
      commandLine: npm start
      workingDir: ${PROJECT_SOURCE}
      group:
        kind: run
        isDefault: true

For testing and debugging we will also need to define commands for each with the shell commands used to debug and test your project

The kind of commands will be debug and test for running your debugging and testing respectively

commands:
  - id: install
    exec:
      component: runtime
      commandLine: npm install
      workingDir: ${PROJECT_SOURCE}
      group:
        kind: build
        isDefault: true
  - id: run
    exec:
      component: runtime
      commandLine: npm start
      workingDir: ${PROJECT_SOURCE}
      group:
        kind: run
        isDefault: true
  - id: debug
    exec:
      component: runtime
      commandLine: npm run debug
      workingDir: ${PROJECT_SOURCE}
      group:
        kind: debug
        isDefault: true
  - id: test
    exec:
      component: runtime
      commandLine: npm test
      workingDir: ${PROJECT_SOURCE}
      group:
        kind: test
        isDefault: true

Final innerloop devfile

devfile.yaml

schemaVersion: 2.2.2
metadata:
  name: nodejs
components:
  - name: runtime
    container:
      image: registry.access.redhat.com/ubi8/nodejs-18:latest
      args: ['tail', '-f', '/dev/null']
      memoryLimit: 1024Mi
      mountSources: true
      env:
        - name: DEBUG_PORT
          value: '5858'
      endpoints:
        - name: http-node
          targetPort: 3000
        - exposure: none
          name: debug
          targetPort: 5858
commands:
  - id: install
    exec:
      component: runtime
      commandLine: npm install
      workingDir: ${PROJECT_SOURCE}
      group:
        kind: build
        isDefault: true
  - id: run
    exec:
      component: runtime
      commandLine: npm start
      workingDir: ${PROJECT_SOURCE}
      group:
        kind: run
        isDefault: true
  - id: debug
    exec:
      component: runtime
      commandLine: npm run debug
      workingDir: ${PROJECT_SOURCE}
      group:
        kind: debug
        isDefault: true
  - id: test
    exec:
      component: runtime
      commandLine: npm test
      workingDir: ${PROJECT_SOURCE}
      group:
        kind: test
        isDefault: true

The component and commands here allow the developer to build, run, debug, and test their project within a local cluster using a devfile supported development tool (e.g. odo).

What is outerloop?

Outerloop deployments are ones done after the development stage once the source is checked into the source repository. Such deployments would include integration testing, full builds or deployments.

Procedure

Add an image component to define the image building process

Label your image tag with imageNameSelector
Define your dockerfile with your file path, build context and if your build requires root privileges

components:
  - name: outerloop-build
    image:
      imageNameSelector: landingpage-image:latest
      dockerfile:
        uri: docker/Dockerfile
        buildContext: .
        rootRequired: false

Add a command which will instruct your deployment to build the docker image using the image component
```
commands:
  - id: build-image
    apply:
      component: outerloop-build
```

Add a deployment component that best suits your cluster’s runtime environment (kubernetes/openshift), in this case openshift

Provide the file path to your openshift template file with uri

components:
  - name: outerloop-build
    image:
      imageNameSelector: landingpage-image:latest
        dockerfile:
          uri: docker/Dockerfile
          buildContext: .
          rootRequired: false
  - name: outerloop-deploy
    openshift:
      uri: landingpage-template.yaml

As with the image component, we will need to create a command for the openshift component

commands:
  - id: build-image
    apply:
      component: outerloop-build
  - id: deploy-openshift
    apply:
      component: outerloop-deploy

To complete the deployment process, combine the two commands into a complete deploy command using composite

commands:
  - id: build-image
    apply:
      component: outerloop-build
  - id: deploy-openshift
    apply:
      component: outerloop-deploy
  - id: deploy
    composite:
      commands:
        - build-image
        - deploy-openshift
      group:
        kind: deploy
        isDefault: true

Final outerloop devfile

devfile.yaml

schemaVersion: 2.2.2
metadata:
  name: nodejs
components:
  - name: outerloop-build
    image:
      imageNameSelector: landingpage-image:latest
      dockerfile:
        uri: docker/Dockerfile
        buildContext: .
        rootRequired: false
  - name: outerloop-deploy
    openshift:
      uri: landingpage-template.yaml
commands:
  - id: build-image
    apply:
      component: outerloop-build
  - id: deploy-openshift
    apply:
      component: outerloop-deploy
  - id: deploy
    composite:
      commands:
        - build-image
        - deploy-openshift
      group:
        kind: deploy
        isDefault: true

With these components and commands, the developer can produce a full build and deployment. In this case, the project has an OpenShift deployment template landingpage-template.yaml for a full deploy and docker image build file docker/Dockerfile for a full build. These actions can also be used for the requirements of performing integration testing.

Support list of developer tools

Though the devfile spec does support both innerloop and outerloop deployments, not all developer tools will support these deployments in the same way. This section will list the devfile supported development tools and what deployment scopes they support.

Developer Tools

Tool	Innerloop Support	Outerloop Support
Odo v2	X	X
Odo v3	X	X
Eclipse Che	X
Amazon CodeCatalyst	X
JetBrains Space Cloud Dev	X	X (image build only)
Red Hat OpenShift Dev Spaces	X
OpenShift Dev Console		X
VSCode OpenShift Toolkit	X	X
IntelliJ OpenShift Toolkit	X	X

Odo Spec Support

Odo covers the features supported by the devfile 2.2.0 spec with minor requirements for version 3:

In order to debug your project it is required to define a debug port: https://odo.dev/docs/user-guides/v3-migration-guide#changes-to-the-way-component-debugging-works
By default, odo v3 sets up an underlying persistent volumes rather than setting up ephemeral volumes, this can be toggled back: https://odo.dev/docs/user-guides/v3-migration-guide#ephemeral-storage

More information on how odo treats lifecycle events can be found on the odo v2 page or on the odo v3 page.

OpenShift Toolkit for both VSCode and IntelliJ IDE use odo v3 to power the core commands, therefore the devfile support should be the same as odo v3.

Eclipse Che Spec Support

As shown in the previous table Eclipse Che only supports innerloop spec features and is currently working on support for outerloop. The Eclipse Che project provides an updated support list of Devfile 2.x in an issue: https://github.com/eclipse/che/issues/17883

Red Hat OpenShift Dev Spaces upstreams the Eclipse Che project and therefore should provide the same level of devfile support.

OpenShift Dev Console Spec Support

OpenShift Dev Console allows the deployment of samples and only supports devfiles defined for outerloop deployments. Additional information about this can be found: https://docs.openshift.com/container-platform/4.10/applications/creating_applications/odc-creating-applications-using-developer-perspective.html

Amazon CodeCatalyst Spec Support

Amazon CodeCatalyst uses devfile specification 2.1.0 and it therefore does not support features the latest devfile specification provides, such as outerloop deployments. More information about Amazon CodeCatalyst’s utilization of devfiles can be found on their documentation pages: https://docs.aws.amazon.com/codecatalyst/latest/userguide/devenvironment.html

JetBrains Space Cloud Dev Spec Support

JetBrains Space Cloud Dev uses the 2.2.0 devfile specification and supports the use of multiple devfiles in a single project. It uses a custom space field under the top level attributes to define the setup for the runtime environment to be set up on the platform. An example of a devfile you might see in this environment is shown below:

Example of JetBrains Space Cloud Dev devfile setup

devfile.yaml

schemaVersion: 2.2.0
metadata:
  name: 'My custom dev env configuration'
attributes:
  space:
    # regular, large, xlarge
    instanceType: large
    # a default IDE for the project
    editor:
      # (Required) IDE type: Idea, WebStorm, PyCharm,
      # RubyMine, CLion, Fleet, GoLand, PhpStorm
      type: Idea
      version: '2022.1'
      # Space uses JetBrains Toolbox App to install IDEs to a dev environment.
      # updateChannel defines IDE version release stage: Release, EAP
      updateChannel: EAP
      # JVM configuration (appends to the default .vmoptions file)
      vmoptions:
      - '-Xms2048m'
      - '-Xmx4096m'
    # a warm-up snapshot
    warmup:
      # create a snapshot every Sunday (only for main branch)
      startOn:
      - type: schedule
        cron: '0 0 0 ? * SUN *'
      # run additional warmup script (IDE indexes will be built anyway)
      script:
        ./scripts/warmup.sh
    # Parameters and secretes required by a dev environment
    # e.g., credentials to an external service
    requiredParameters:
    # (Required) the name of the environment variable
    # that will be available in the dev environment
    - name: USERNAME
      description: 'Space username'
    requiredSecrets:
    - name: PASSWORD
      description: 'Space permanent token'
components:
- name: dev-container
  # Dev environment container config
  container:
    # use image from a Space Packages registry
    image: mycompany.registry.jetbrains.space/p/myprj/container/my-dev-image:27
    # environment variables
    env:
      - name: API_URL
        value: 'https://my-site/http_api'
      - name: PATH_IMG
        value: './img/'

JetBrains Space Cloud Dev also partially supports outerloop via the image component to set up Dockerfile builds:

Example of JetBrains Space Cloud Dev image build devfile setup

devfile.yaml

schemaVersion: 2.2.0
attributes:
  space:
    instanceType: large
    editor:
    type: Idea
components:
- name: image-build
  image:
    # (Required)
    imageName: my-image:latest
    dockerfile:
      # (Optional) path to Docker context relative to projectRoot
      # by default, projectRoot is repository root
      buildContext: docker
      # (Required) path to Dockerfile relative to projectRoot
      uri: docker/Dockerfile
      args:
      - 'ARG1=A'
      - 'ARG2=B'

The image component build process publishes the built image to a cluster image registry specific to your project workspace. More details about using devfiles with JetBrains Space Cloud Dev can be found here: https://www.jetbrains.com/help/space/set-up-a-dev-evnvironment.html

Additional Resources

More information on supported developer tools can be found in Developing with devfiles
Standardizing application delivery with OpenShift

Devfile.io

Prerequisites

What is innerloop?

Procedure

Final innerloop devfile

What is outerloop?

Procedure

Final outerloop devfile

Support list of developer tools

Developer Tools

Odo Spec Support

Eclipse Che Spec Support

OpenShift Dev Console Spec Support

Amazon CodeCatalyst Spec Support

JetBrains Space Cloud Dev Spec Support

Example of JetBrains Space Cloud Dev devfile setup

Example of JetBrains Space Cloud Dev image build devfile setup

Additional Resources