Builtin args

Builtin args are variables with values automatically filled-in by Earthly.
The value of a builtin arg can never be overridden. However, you can always have an additional ARG, which takes as the default value, the value of the builtin arg. The additional arg can be overridden. Example
ARG EARTHLY_TARGET_TAG
ARG TAG=$EARTHLY_TARGET_TAG
SAVE IMAGE --push some/name:$TAG
Important
In contrast to Dockerfile predefined args, Earthly builtin args need to be pre-declared before they can be used. For example
ARG EARTHLY_TARGET
RUN echo "The current target is $EARTHLY_TARGET"
The following builtin args are available
Name
Description
Example value
EARTHLY_TARGET
The canonical reference of the current target.
For example, for a target named foo, which exists on john/work branch, in a repository at github.com/bar/buz, in a subdirectory src, the canonical reference would be github.com/bar/buz/src:john/work+foo. For more information about canonical references, see target referencing.
EARTHLY_TARGET_PROJECT
The project part of the canonical reference of the current target.
For the example above, the canonical project would be github.com/bar/buz/src
EARTHLY_TARGET_NAME
The name part of the canonical reference of the current target.
For the example above, the name would be foo
EARTHLY_TARGET_TAG
The tag part of the canonical reference of the current target. Note that if the target has no canonical form, the value is an empty string.
For the example above, the tag would be john/work
EARTHLY_TARGET_TAG_DOCKER
The tag part of the canonical reference of the current target, sanitized for safe use as a docker tag. This is guaranteed to be a valid docker tag, even if no canonical form exists, in which case, latest is used.
For the example above, the docker tag would be john_work
EARTHLY_GIT_HASH
The git hash detected within the build context directory. If no git directory is detected, then the value is an empty string. Take care when using this arg, as the frequently changing git hash may be cause for not using the cache.
41cb5666ade67b29e42bef121144456d3977a67a
EARTHLY_GIT_ORIGIN_URL
The git URL detected within the build context directory. If no git directory is detected, then the value is an empty string.
[email protected]:earthly/earthly.git
EARTHLY_GIT_PROJECT_NAME
The git project name from within the git URL detected within the build context directory. If no git directory is detected, then the value is an empty string.
earthly/earthly
TARGETPLATFORM
(experimental) The target platform the target is being built for.
linux/arm/v7, linux/amd64
TARGETOS
(experimental) The target OS the target is being built for.
linux
TARGETARCH
(experimental) The target processor architecture the target is being built for.
arm, amd64
TARGETVARIANT
(experimental) The target processor architecture variant the target is being built for.
v7
Note
The classical Dockerfile predefined args are currently not available in Earthly.

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Earthfile reference

Excluding patterns

Last updated 3 months ago

Name	Description	Example value
`EARTHLY_TARGET`	The canonical reference of the current target.	For example, for a target named `foo`, which exists on `john/work` branch, in a repository at `github.com/bar/buz`, in a subdirectory `src`, the canonical reference would be `github.com/bar/buz/src:john/work+foo`. For more information about canonical references, see target referencing.
`EARTHLY_TARGET_PROJECT`	The project part of the canonical reference of the current target.	For the example above, the canonical project would be `github.com/bar/buz/src`
`EARTHLY_TARGET_NAME`	The name part of the canonical reference of the current target.	For the example above, the name would be `foo`
`EARTHLY_TARGET_TAG`	The tag part of the canonical reference of the current target. Note that if the target has no canonical form, the value is an empty string.	For the example above, the tag would be `john/work`
`EARTHLY_TARGET_TAG_DOCKER`	The tag part of the canonical reference of the current target, sanitized for safe use as a docker tag. This is guaranteed to be a valid docker tag, even if no canonical form exists, in which case, `latest` is used.	For the example above, the docker tag would be `john_work`
`EARTHLY_GIT_HASH`	The git hash detected within the build context directory. If no git directory is detected, then the value is an empty string. Take care when using this arg, as the frequently changing git hash may be cause for not using the cache.	`41cb5666ade67b29e42bef121144456d3977a67a`
`EARTHLY_GIT_ORIGIN_URL`	The git URL detected within the build context directory. If no git directory is detected, then the value is an empty string.	`[email protected]:earthly/earthly.git`
`EARTHLY_GIT_PROJECT_NAME`	The git project name from within the git URL detected within the build context directory. If no git directory is detected, then the value is an empty string.	`earthly/earthly`
`TARGETPLATFORM`	(experimental) The target platform the target is being built for.	`linux/arm/v7`, `linux/amd64`
`TARGETOS`	(experimental) The target OS the target is being built for.	`linux`
`TARGETARCH`	(experimental) The target processor architecture the target is being built for.	`arm`, `amd64`
`TARGETVARIANT`	(experimental) The target processor architecture variant the target is being built for.	`v7`