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Dagger Environment Variables Reference

caution

This documentation is for an older version of Dagger, which is no longer actively maintained.

We encourage you to refer to the documentation for the most current version.

Dagger supports a variety of environment variables.

They have two purposes:

  • Extend Dagger capabilities
  • Persist CLI options

Extend Dagger capabilities

Dagger aims to fit any use case, even the most specific ones. To avoid burdening the user experience with rarely used options, a small list of environment variables can be set:

Environment variableSourceDescription
BUILDKIT_HOSTcustom buildkitLink Dagger to custom Buildkit instance
DOCKER_HOSTcustom buildkit w/DockerLink Dagger to custom Buildkit instance running in Docker
OTEL_EXPORTER_JAEGER_ENDPOINTopentelemetryOpentelemetry Jaeger endpoint
JAEGER_TRACEopentelemetryJaeger UI endpoint
DOCKERHUB_AUTH_USERimage.cueDocker.#Pull repository login
DOCKERHUB_AUTH_PASSWORDimage.cueDocker.#Pull repository password

Persist CLI options

As Dagger relies on Viper to manage the CLI inputs, all its option can be replaced with environment variables:

dagger version

optionUsageDescription
--checkexport DAGGER_CHECK=1check if dagger is up to date

dagger project

init

optionUsageDescription
--nameexport DAGGER_NAME=stringproject name
--templateexport DAGGER_TEMPLATE=stringTemplate name [hello]

update

optionUsageDescription
--private-key-fileexport DAGGER_PRIVATE_KEY_FILE=stringPrivate ssh key
--private-key-passwordexport DAGGER_PRIVATE_KEY_PASSWORD=stringPrivate ssh key password
--updateexport DAGGER_UPDATE=1Update to latest version of specified packages

info

optionUsageDescription
--planexport DAGGER_PLAN=stringPath to plan (defaults to current directory) (default ".")

dagger do

optionUsageDescription
--cache-fromexport DAGGER_CACHE_FROM=stringExternal cache sources (eg. user/app:cache, type=local,src=path/to/dir)
--cache-toexport DAGGER_CACHE_TO=stringCache destinations (eg. user/app:cache, type=local,dest=path/to/dir)
--dry-runexport DAGGER_DRY_RUN=1Dry run mode
--no-cacheexport DAGGER_NO_CACHE=1Disable caching
--outputexport DAGGER_OUTPUT=stringFile path to write the action's output values. Prints to stdout if empty
--output-formatexport DAGGER_OUTPUT_FORMAT=stringFormat for output values (plain, json, yaml)
--planexport DAGGER_PLAN=stringPath to plan (defaults to current directory) (default ".")
--platformexport DAGGER_PLATFORM=stringSet target build platform (requires experimental)
--withexport DAGGER_WITH=stringSet value of dagger value at runtime