dokku/docs/deployment/builders/cloud-native-buildpacks.md

Cloud Native Buildpacks

Important

New as of 0.22.0

builder-pack:report [<app>] [<flag>]   # Displays a builder-pack report for one or more apps
builder-pack:set <app> <key> (<value>) # Set or clear a builder-pack property for an app

buildpacks:set-property [--global|<app>] <key> <value>  # Set or clear a buildpacks property for an app

Cloud Native Buildpacks are an evolution over the Buildpacks technology provided by the Herokuish builder. See the herokuish buildpacks documentation for more information on how to clear buildpack build cache for an application.

Warning

This functionality uses the pack cli from the Cloud Native Buildpacks project to build apps. As the integration is experimental in Dokku, it is likely to change over time.

Usage

Requirements

The pack cli tool is not included by default with Dokku or as a dependency. It must also be installed as shown on this page.

Builds will proceed with the pack cli for the app from then on.

Caveats

As this functionality is highly experimental, there are a number of caveats. Please note that not all issues are listed below.

• Specifying specific buildpacks is not currently possible.
  • A future release will add support for specifying buildpacks via the buildpacks plugin.
• There is currently no way to specify extra arguments for pack cli invocations.
  • A future release will add support for injecting extra arguments during the build process.
• The default process type is web.
• Build cache is stored in Docker volumes instead of on disk. As such, repo:purge-cache currently has no effect.
  • A future version will add integration with the repo plugin.
• pack is not currently included with Dokku, nor is it added as a package dependency.
  • A future version will include it as a package dependency.

Detection

This builder will be auto-detected in either the following cases:

• The DOKKU_CNB_EXPERIMENTAL app environment variable is set to 1.

  dokku config:set --no-restart node-js-app DOKKU_CNB_EXPERIMENTAL=1
  

• A project.toml file exists in the root of the app repository.

  • This file is consumed by pack-cli and used to describe how the app is built.

The builder can also be specified via the builder:set command:

dokku builder:set node-js-app selected pack

Dokku will only select the dockerfile builder if both the herokuish and pack builders are not detected and a Dockerfile exists. See the dockerfile builder documentation for more information on how that builder functions.

Changing the project.toml location

The project.toml is expected to be found in a specific directory, depending on the deploy approach:

• The WORKDIR of the Docker image for deploys resulting from git:from-image and git:load-image commands.
• The root of the source code tree for all other deploys (git push, git:from-archive, git:sync).

Sometimes it may be desirable to set a different path for a given app, e.g. when deploying from a monorepo. This can be done via the projecttoml-path property:

dokku builder-pack:set node-js-app projecttoml-path .dokku/project.toml

The value is the path to the desired file relative to the base search directory, and will never be treated as absolute paths in any context. If that file does not exist within the repository, Dokku will continue the build process as if the repository has no project.toml.

The default value may be set by passing an empty value for the option:

dokku builder-pack:set node-js-app projecttoml-path

The projecttoml-path property can also be set globally. The global default is project.toml, and the global value is used when no app-specific value is set.

dokku builder-pack:set --global projecttoml-path project2.toml

The default value may be set by passing an empty value for the option.

dokku builder-pack:set --global projecttoml-path

Displaying builder-pack reports for an app

Important

New as of 0.25.0

You can get a report about the app's storage status using the builder-pack:report command:

dokku builder-pack:report

=====> node-js-app builder-pack information
       Builder pack computed projecttoml path: project2.toml
       Builder pack global projecttoml path:   project.toml
       Builder pack projecttoml path:          project2.toml
=====> python-sample builder-pack information
       Builder pack computed projecttoml path: project.toml
       Builder pack global projecttoml path:   project.toml
       Builder pack projecttoml path:
=====> ruby-sample builder-pack information
       Builder pack computed projecttoml path: project.toml
       Builder pack global projecttoml path:   project.json
       Builder pack projecttoml path:

You can run the command for a specific app also.

dokku builder-pack:report node-js-app

=====> node-js-app builder-pack information
       Builder pack computed projecttoml path: project2.toml
       Builder pack global projecttoml path:   project.toml
       Builder pack projecttoml path:          project2.toml

You can pass flags which will output only the value of the specific information you want. For example:

dokku builder-pack:report node-js-app --builder-pack-projecttoml-path

project2.toml

Customizing the Buildpack stack builder

Important

New as of 0.23.0

The default stack builder in use by CNB buildpacks in Dokku is based on heroku/builder:24. Users may desire to switch the stack builder to a custom version, either to update the operating system or to customize packages included with the stack builder. This can be performed via the buildpacks:set-property command.

dokku buildpacks:set-property node-js-app stack paketobuildpacks/build:base-cnb

The specified stack builder can also be unset by omitting the name of the stack builder when calling buildpacks:set-property.

dokku buildpacks:set-property node-js-app stack

A change in the stack builder value will execute the post-stack-set trigger.

Finally, stack builders can be set or unset globally as a fallback. This will take precedence over a globally set DOKKU_CNB_BUILDER environment variable (heroku/builder:24 by default).

# set globally
dokku buildpacks:set-property --global stack paketobuildpacks/build:base-cnb

# unset globally
dokku buildpacks:set-property --global stack

Specifying commands via Procfile

See the Procfile documentation for more information on how to specify different processes for your app.