Support environment variables

Summary:
Added support for definition of environment variables under
`runs.environment`. Corresponding `ENV` instructions will be added to
Dockerfile output for the unprivileged build phase.

Fixes T168425

Test Plan: Run `go test ./...`.

Reviewers: thcipriani, mobrovac, hashar, Jrbranaa, mmodell, #release-engineering-team

Reviewed By: mobrovac

Tags: #release-engineering-team

Maniphest Tasks: T168425

Differential Revision: https://phabricator.wikimedia.org/D691

2 files changed, 13 insertions, 15 deletions

diff --git a/docker/compiler.go b/docker/compiler.go
index f398164..7f030cf 100644
--- a/docker/compiler.go
+++ b/docker/compiler.go
@@ -97,7 +97,7 @@ func CompileInstruction(buffer *bytes.Buffer, instruction build.Instruction) {
 	case build.Copy:
 		Writeln(buffer, "COPY [\"", instruction.Arguments[0], "\", \"", instruction.Arguments[1], "\"]")
 	case build.Env:
-		Writeln(buffer, "ENV ", strings.Join(instruction.Arguments, " "))
+		Writeln(buffer, "ENV ", strings.Join(instruction.Arguments, " \\\n    "))
 	}
 }
 
diff --git a/docker/compiler_test.go b/docker/compiler_test.go
index 7f6ee87..0b2d907 100644
--- a/docker/compiler_test.go
+++ b/docker/compiler_test.go
@@ -12,10 +12,9 @@ import (
 
 func TestSingleStageHasNoName(t *testing.T) {
 	cfg, err := config.ReadConfig([]byte(`---
-base: foo/bar
-variants:
-  development: {}
-`))
+    base: foo/bar
+    variants:
+      development: {}`))
 
 	assert.Nil(t, err)
 
@@ -26,15 +25,14 @@ variants:
 
 func TestMultiStageIncludesStageNames(t *testing.T) {
 	cfg, err := config.ReadConfig([]byte(`---
-base: foo/bar
-variants:
-  build: {}
-  production:
-    artifacts:
-      - from: build
-        source: .
-        destination: .
-`))
+    base: foo/bar
+    variants:
+      build: {}
+      production:
+        artifacts:
+          - from: build
+            source: .
+            destination: .`))
 
 	assert.Nil(t, err)
 
@@ -59,5 +57,5 @@ func TestCompileInstructionEnv(t *testing.T) {
 
 	docker.CompileInstruction(buffer, instruction)
 
-	assert.Equal(t, "ENV foo=bar baz=qux\n", buffer.String())
+	assert.Equal(t, "ENV foo=bar \\\n    baz=qux\n", buffer.String())
 }