Allow set container_image labels by json file

Author: bozaro

container/go/cmd/create_image_config/create_image_config.go

@@ -19,6 +19,7 @@ package main
 
 import (
 	"bytes"
+	"encoding/json"
 	"flag"
 	"io/ioutil"
 	"log"
@@ -43,6 +44,7 @@ var (
 	operatingSystem    = flag.String("operatingSystem", "linux", "Operating system to create docker image for, eg. linux.")
 	osVersion          = flag.String("osVersion", "", "Operating system version to create docker image for (primarily for windows).")
 	labelsArray        utils.ArrayStringFlags
+	labelFilesArray    utils.ArrayStringFlags
 	ports              utils.ArrayStringFlags
 	volumes            utils.ArrayStringFlags
 	entrypointPrefix   utils.ArrayStringFlags
@@ -55,6 +57,7 @@ var (
 
 func main() {
 	flag.Var(&labelsArray, "labels", "Augment the Label of the previous layer.")
+	flag.Var(&labelFilesArray, "labelFile", "Augment the Label of the previous layer (json file with string-to-string dict).")
 	flag.Var(&ports, "ports", "Augment the ExposedPorts of the previous layer.")
 	flag.Var(&volumes, "volumes", "Augment the Volumes of the previous layer.")
 	flag.Var(&entrypointPrefix, "entrypointPrefix", "Prefix the Entrypoint with the specified arguments.")
@@ -83,6 +86,20 @@ func main() {
 		}
 	}
 
+	for _, labelFile := range labelFilesArray {
+		labelsBlob, err := ioutil.ReadFile(labelFile)
+		if err != nil {
+			log.Fatalf("Failed to read the labels JSON file: %v", err)
+		}
+		labels := make(map[string]string)
+		if err := json.Unmarshal(labelsBlob, &labels); err != nil {
+			log.Fatalf("Can't parse JSON file %q: %v", labelFile, err)
+		}
+		for name, value := range labels {
+			labelsArray = append(labelsArray, name+"="+value)
+		}
+	}
+
 	stamper, err := compat.NewStamper(stampInfoFile)
 	if err != nil {
 		log.Fatalf("Failed to initialize the stamper: %v", err)

container/image.bzl

@@ -107,6 +107,10 @@ def _add_create_image_config_args(
     for key, value in labels.items():
         args.add("-labels", "{}={}".format(key, value))
 
+    for label_file in ctx.files.label_files:
+        args.add("-labelFile", label_file)
+    inputs += ctx.files.label_files
+
     for key, value in env.items():
         args.add("-env", "%s" % "=".join([
             ctx.expand_make_variables("env", key, {}),
@@ -121,8 +125,8 @@ def _add_create_image_config_args(
     inputs += layer_names
     args.add_all(layer_names, before_each = "-layerDigestFile", format_each = "@%s")
 
-    if ctx.attr.label_files:
-        inputs += ctx.files.label_files
+    if ctx.attr.label_file_deps:
+        inputs += ctx.files.label_file_deps
 
     if base_config:
         args.add("-baseConfig", base_config)
@@ -178,7 +182,7 @@ def _image_config(
     manifest = ctx.actions.declare_file(name + "." + layer_name + ".manifest")
 
     label_file_dict = _string_to_label(
-        ctx.files.label_files,
+        ctx.files.label_file_deps,
         ctx.attr.label_file_strings,
     )
 
@@ -640,7 +644,7 @@ _attrs = dicts.add(_layer.attrs, {
     ),
     "label_file_strings": attr.string_list(),
     # Implicit/Undocumented dependencies.
-    "label_files": attr.label_list(
+    "label_file_deps": attr.label_list(
         allow_files = True,
     ),
     "labels": attr.string_dict(
@@ -661,6 +665,20 @@ _attrs = dicts.add(_layer.attrs, {
 
         The values of this field support stamp variables.""",
     ),
+    "label_files": attr.label_list(
+        doc = """List of JSON files contains simple string-to-string dictionary with
+        labels.
+
+        Example of file content:
+
+            {
+                "com.example.foo": "bar",
+                "com.example.baz": "@metadata.json"
+            }
+
+        The values of this field support stamp variables.""",
+        allow_files = True,
+    ),
     "launcher": attr.label(
         allow_single_file = True,
         doc = """If present, prefix the image's ENTRYPOINT with this file.
@@ -1006,7 +1024,7 @@ def container_image(**kwargs):
             )
 
     reserved_attrs = [
-        "label_files",
+        "label_file_deps",
         "label_file_strings",
         "null_cmd",
         "null_entrypoint",
@@ -1018,7 +1036,7 @@ def container_image(**kwargs):
 
     if "labels" in kwargs:
         files = sorted({v[1:]: None for v in kwargs["labels"].values() if v[0] == "@"}.keys())
-        kwargs["label_files"] = files
+        kwargs["label_file_deps"] = files
         kwargs["label_file_strings"] = files
 
     # If cmd is set but set to None, [] or "",