feature-flag EARTHLY_CI arg

Signed-off-by: Alex Couture-Beil <alex@earthly.dev>

CHANGELOG.md

@@ -8,7 +8,7 @@ All notable changes to [Earthly](https://github.com/earthly/earthly) will be doc
 
 - Added support for a custom `.netrc` file path using the standard `NETRC` environmental variable. [#2426](https://github.com/earthly/earthly/pull/2426)
 - Ability to run multiple Earthly installations at a time via `EARTHLY_INSTALLATION_NAME` environment variable, or the `--installation-name` CLI flag. The installation name defaults to `earthly` if not specified. Different installations use different configurations, different buildkit Daemons, different cache volumes, and different ports.
-- New `EARTHLY_CI` builtin arg, which is set to `true` when earthly is run with the `--ci` flag. [#2398](https://github.com/earthly/earthly/pull/2398)
+- New `EARTHLY_CI` builtin arg, which is set to `true` when earthly is run with the `--ci` flag, this ARG must be enabled with the `VERSION --ci-arg` feature flag.. [#2398](https://github.com/earthly/earthly/pull/2398)
 
 ### Changed
 

features/features.go

@@ -43,6 +43,7 @@ type Features struct {
 	WaitBlock                  bool `long:"wait-block" description:"enable WITH/END feature, also allows RUN --push mixed with non-push commands"`
 	UseProjectSecrets          bool `long:"use-project-secrets" description:"enable project-based secret resolution"`
 	UsePipelines               bool `long:"use-pipelines" description:"enable the PIPELINE and TRIGGER commands"`
+	EarthlyCIArg               bool `long:"ci-arg" description:"include EARTHLY_CI arg"`
 
 	NoUseRegistryForWithDocker bool `long:"no-use-registry-for-with-docker" description:"disable use-registry-for-with-docker"`
 

tests/ci-arg.earth

@@ -1,4 +1,4 @@
-VERSION 0.6
+VERSION --ci-arg 0.6
 FROM alpine:3.15
 
 ci-test:

variables/builtin.go

@@ -25,7 +25,6 @@ type DefaultArgs struct {
 // BuiltinArgs returns a scope containing the builtin args.
 func BuiltinArgs(target domain.Target, platr *platutil.Resolver, gitMeta *gitutil.GitMetadata, defaultArgs DefaultArgs, ftrs *features.Features, push bool, ci bool) *Scope {
 	ret := NewScope()
-	ret.AddInactive(arg.EarthlyCI, fmt.Sprintf("%t", ci))
 	ret.AddInactive(arg.EarthlyTarget, target.StringCanonical())
 	ret.AddInactive(arg.EarthlyTargetProject, target.ProjectCanonical())
 	targetNoTag := target
@@ -48,6 +47,10 @@ func BuiltinArgs(target domain.Target, platr *platutil.Resolver, gitMeta *gituti
 		ret.AddInactive(arg.EarthlyBuildSha, defaultArgs.EarthlyBuildSha)
 	}
 
+	if ftrs.EarthlyCIArg {
+		ret.AddInactive(arg.EarthlyCI, fmt.Sprintf("%t", ci))
+	}
+
 	if ftrs.EarthlyLocallyArg {
 		SetLocally(ret, false)
 	}