custom_build: add EXPECTED_{IMAGE,TAG,REGISTRY} env vars (#5743)

Currently, we pass `EXPECTED_REF`, which is the full image reference
including registry, path, and tag.

Some build scripts want to consume these independently, so in addition
to passing the full reference, this adds the individual components as
well.

There's a slight behavior change here in that previously, the registry
was passed as `REGISTRY_HOST` only in the case that
`outputs_image_ref_to` mode was being used. Now, it's _always_ passed
(if there is a local registry!) regardless of custom build mode along
with `EXPECTED_REGISTRY`, which is new and duplicative but consistent
with the other names. This should be harmless, however.

Closes #5433.

internal/build/custom_builder.go

@@ -8,6 +8,7 @@ import (
 	"os/exec"
 	"strings"
 
+	"github.com/docker/distribution/reference"
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 	ktypes "k8s.io/apimachinery/pkg/types"
@@ -37,9 +38,9 @@ func (b *CustomBuilder) Build(ctx context.Context, refs container.RefSet,
 	imageMaps map[ktypes.NamespacedName]*v1alpha1.ImageMap) (container.TaggedRefs, error) {
 	expectedTag := spec.OutputTag
 	outputsImageRefTo := spec.OutputsImageRefTo
+	registryHost := refs.Registry().Host
 
 	var expectedBuildRefs container.TaggedRefs
-	var registryHost string
 	var err error
 
 	// There are 3 modes for determining the output tag.
@@ -49,10 +50,6 @@ func (b *CustomBuilder) Build(ctx context.Context, refs container.RefSet,
 
 		// Remove the output file, ignoring any errors.
 		_ = os.Remove(outputsImageRefTo)
-
-		// Inform the user script about the registry host
-		registryHost = refs.Registry().Host
-
 	} else if expectedTag != "" {
 		// If the tag is coming from the user script, we expect that the user script
 		// also doesn't know about the local registry. So we have to strip off
@@ -83,10 +80,18 @@ func (b *CustomBuilder) Build(ctx context.Context, refs container.RefSet,
 	if expectedBuildResult != nil {
 		extraEnvVars = append(extraEnvVars,
 			fmt.Sprintf("EXPECTED_REF=%s", container.FamiliarString(expectedBuildResult)))
+		extraEnvVars = append(extraEnvVars,
+			fmt.Sprintf("EXPECTED_IMAGE=%s", reference.Path(expectedBuildResult)))
+		extraEnvVars = append(extraEnvVars,
+			fmt.Sprintf("EXPECTED_TAG=%s", expectedBuildResult.Tag()))
 	}
 	if registryHost != "" {
+		// kept for backwards compatibility
 		extraEnvVars = append(extraEnvVars,
 			fmt.Sprintf("REGISTRY_HOST=%s", registryHost))
+		// for consistency with other EXPECTED_* vars
+		extraEnvVars = append(extraEnvVars,
+			fmt.Sprintf("EXPECTED_REGISTRY=%s", registryHost))
 	}
 
 	extraEnvVars = append(extraEnvVars, b.dCli.Env().AsEnviron()...)

internal/build/custom_builder_test.go

@@ -223,6 +223,66 @@ func TestCustomBuildImageDep(t *testing.T) {
 	assert.Equal(f.t, "base:tilt-12345", strings.TrimSpace(f.ReadFile("image-0.txt")))
 }
 
+func TestEnvVars(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("no sh on windows")
+	}
+
+	expectedVars := map[string]string{
+		"EXPECTED_REF":      "localhost:1234/foo_bar:tilt-build-1551202573",
+		"EXPECTED_REGISTRY": "localhost:1234",
+		"EXPECTED_IMAGE":    "foo_bar",
+		"EXPECTED_TAG":      "tilt-build-1551202573",
+		"REGISTRY_HOST":     "localhost:1234",
+	}
+	var script []string
+	for k, v := range expectedVars {
+		script = append(script, fmt.Sprintf(
+			`if [ "${%s}" != "%s" ]; then >&2 printf "%s:\n\texpected: %s\n\tactual:   ${%s}\n"; exit 1; fi`,
+			k, v, k, v, k))
+	}
+
+	f := newFakeCustomBuildFixture(t)
+	sha := digest.Digest("sha256:11cd0eb38bc3ceb958ffb2f9bd70be3fb317ce7d255c8a4c3f4af30e298aa1aab")
+	f.dCli.Images["localhost:1234/foo_bar:tilt-build-1551202573"] = types.ImageInspect{ID: string(sha)}
+	cb := f.customBuild(strings.Join(script, "\n"))
+	_, err := f.cb.Build(f.ctx, refSetWithRegistryFromString("foo/bar", TwoURLRegistry), cb.CmdImageSpec, nil)
+	require.NoError(t, err)
+}
+
+func TestEnvVars_ConfigRefWithLocalRegistry(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("no sh on windows")
+	}
+
+	// generally, config refs (value in Tiltfile) are $prod_registry/$image:$tag
+	// and Tilt rewrites it to $local_registry/$sanitized_prod_registry_$image
+	// however, some users explicitly use the $local_registry in their Tiltfile
+	// refs, so instead of producing a redudant and confusing ref like
+	// $local_registry/$sanitized_local_registry_$image, it just gets passed
+	// through
+	expectedVars := map[string]string{
+		"EXPECTED_REF":      "localhost:1234/foo/bar:tilt-build-1551202573",
+		"EXPECTED_REGISTRY": "localhost:1234",
+		"EXPECTED_IMAGE":    "foo/bar",
+		"EXPECTED_TAG":      "tilt-build-1551202573",
+		"REGISTRY_HOST":     "localhost:1234",
+	}
+	var script []string
+	for k, v := range expectedVars {
+		script = append(script, fmt.Sprintf(
+			`if [ "${%s}" != "%s" ]; then >&2 printf "%s:\n\texpected: %s\n\tactual:   ${%s}\n"; exit 1; fi`,
+			k, v, k, v, k))
+	}
+
+	f := newFakeCustomBuildFixture(t)
+	sha := digest.Digest("sha256:11cd0eb38bc3ceb958ffb2f9bd70be3fb317ce7d255c8a4c3f4af30e298aa1aab")
+	f.dCli.Images["localhost:1234/foo/bar:tilt-build-1551202573"] = types.ImageInspect{ID: string(sha)}
+	cb := f.customBuild(strings.Join(script, "\n"))
+	_, err := f.cb.Build(f.ctx, refSetWithRegistryFromString("localhost:1234/foo/bar", TwoURLRegistry), cb.CmdImageSpec, nil)
+	require.NoError(t, err)
+}
+
 type fakeCustomBuildFixture struct {
 	*tempdir.TempDirFixture