go_image: implement tag_name (#2206)

This is a follow-up for 7d34678

go/image.bzl

@@ -89,7 +89,7 @@ STATIC_DEFAULT_BASE = select({
     "//conditions:default": "@go_image_static//image",
 })
 
-def go_image(name, base = None, deps = [], layers = [], env = {}, binary = None, **kwargs):
+def go_image(name, base = None, tag_name = None, deps = [], layers = [], env = {}, binary = None, **kwargs):
     """Constructs a container image wrapping a go_binary target.
 
   Args:
@@ -123,6 +123,7 @@ def go_image(name, base = None, deps = [], layers = [], env = {}, binary = None,
     compatible_with = kwargs.get("compatible_with", None)
     app_layer(
         name = name,
+        tag_name = tag_name,
         base = base,
         env = env,
         binary = binary,

testing/e2e/go_image.sh

@@ -31,7 +31,7 @@ function test_go_image_busybox() {
   clear_docker
   bazel run -c dbg tests/container/go:go_image -- --norun
   local number=$RANDOM
-  id=$(docker run -d  --entrypoint=sh bazel/tests/container/go:go_image -c "echo aa${number}bb")
+  id=$(docker run -d  --entrypoint=sh bazel/tests/container/go:go_image-with-our-tag -c "echo aa${number}bb")
   docker wait $id
   logs=$(docker logs $id)
   EXPECT_CONTAINS $logs "aa${number}bb"

tests/container/go/BUILD

@@ -29,6 +29,7 @@ go_image(
     env = {"GO_IMAGE_TEST_KEY": "go_image_test_value"},
     importpath = "github.com/bazelbuild/rules_docker/docker/tests/container/go",
     pure = "off",  # we should be using gcr.io/distroless/base as a base image
+    tag_name = "go_image-with-our-tag",
     tags = [
         "tag1",
         "tag2",