Add helm_template_test.values (#228)

Address part 2 of #226

- Duplicate the `values` argument from `helm_template` into
`helm_template_test`.
- Update a test of `helm_template_test` to uses `values` and also so
that it detects that the extra values files are in fact used.

Author: bcsgh

helm/private/runner/runner.go

@@ -75,6 +75,20 @@ func loadTemplatePatterns(path string) (map[string][]string, error) {
 	return data, nil
 }
 
+// Flag type for a list of values passed as mutiple arguments.
+type valuesList []string
+
+// Provide the flag.Value interface in the simplest possible way.
+func (vs *valuesList) Set(value string) error {
+	*vs = append(*vs, value)
+	return nil
+}
+
+// Provide the flag.Value interface in the simplest possible way.
+func (vs *valuesList) String() string {
+	return fmt.Sprint(*vs)
+}
+
 func main() {
 	// Get the file path for args
 	argsRlocation := os.Getenv("RULES_HELM_HELM_RUNNER_ARGS_FILE")
@@ -92,11 +106,14 @@ func main() {
 
 	internalArgs, helmArgs := parseArgsUpToDashDash(argv)
 
+	var values valuesList
+
 	// Setup flags for helm, chart, registry_url, and image_pushers
 	rawHelmPath := flag.String("helm", "", "Path to helm binary")
 	rawHelmPluginsPath := flag.String("helm_plugins", "", "The path to helm plugins.")
 	rawChartPath := flag.String("chart", "", "Path to Helm .tgz file")
 	rawImagePushers := flag.String("image_pushers", "", "Comma-separated list of image pusher executables")
+	flag.Var(&values, "values", "Extra Values files (maye be used mutiple times).")
 
 	// Parse command line arguments
 	flag.CommandLine.Parse(internalArgs)
@@ -131,6 +148,11 @@ func main() {
 		}
 	}
 
+	for _, value := range values {
+		// Translate to correct path and forward to helm.
+		helmArgs = append(helmArgs, "--values", helm_utils.GetRunfile(value))
+	}
+
 	var imagePushers []string
 	if *rawImagePushers != "" {
 		for _, pusher := range strings.Split(*rawImagePushers, ",") {

helm/private/template.bzl

@@ -12,6 +12,9 @@ def _helm_template_test_impl(ctx):
             ctx.label,
         ))
 
+    if ctx.attr.installer and ctx.files.values:
+        fail("values is not supported with installer")
+
     template_patterns = None
     if ctx.attr.template_patterns:
         template_patterns = ctx.actions.declare_file("{}.template_patterns.json".format(ctx.label.name))
@@ -38,6 +41,10 @@ def _helm_template_test_impl(ctx):
         args.add("-chart", rlocationpath(pkg_info.chart, ctx.workspace_name))
         args.add("-helm", rlocationpath(toolchain.helm, ctx.workspace_name))
         args.add("-helm_plugins", rlocationpath(toolchain.helm_plugins, ctx.workspace_name))
+
+        for values in ctx.files.values:
+            args.add("--values", rlocationpath(values, ctx.workspace_name))
+
         args.add("--")
         args.add("template")
         args.add(rlocationpath(pkg_info.chart, ctx.workspace_name))
@@ -47,7 +54,7 @@ def _helm_template_test_impl(ctx):
             content = args,
         )
 
-        runfiles = runfiles.merge(ctx.runfiles([
+        runfiles = runfiles.merge(ctx.runfiles(ctx.files.values + [
             args_file,
             ctx.executable._runner,
             toolchain.helm,
@@ -108,6 +115,10 @@ helm_template_test = rule(
         "template_patterns": attr.string_list_dict(
             doc = "A mapping of template paths to regex patterns required to match.",
         ),
+        "values": attr.label_list(
+            doc = "Values files to pass to `helm template --values`.",
+            allow_files = [".yml", ".yaml"],
+        ),
         "_copier": attr.label(
             cfg = "exec",
             executable = True,

tests/template_with_values/BUILD.bazel

@@ -22,4 +22,12 @@ helm_template(
 helm_template_test(
     name = "template_with_values_template_test",
     chart = ":template_with_values",
+    template_patterns = {
+        "template-with-values/templates/deployment.yaml": [
+            "  replicas: 10\\b",  # overriden by template_values.yaml
+        ],
+    },
+    values = [
+        ":template_values.yaml",
+    ],
 )