Add extra_values param to app_chart

bazel/app_chart.bzl

@@ -13,11 +13,25 @@ def _impl(ctx):
 
     values_yaml = ctx.actions.declare_file(ctx.label.name + "-values.yaml")
     source_digests = []
-    cmds = [
-        "cat {} - > {} <<EOF".format(ctx.file.values.path, values_yaml.path),
+
+    values_files = [ctx.file.values] + ctx.files.extra_values
+    # Use awk '1' instead of cat to concatenate values files. This ensures that
+    # each file ends with a newline, preventing invalid YAML if an input file
+    # is missing a trailing newline.
+    cmds = ["awk '1' {} > {}".format(ctx.file.values.path, values_yaml.path)]
+    if ctx.files.extra_values:
+        cmds.append("echo '# extra values' >> {}".format(values_yaml.path))
+        cmds.append("awk '1' {} >> {}".format(
+            " ".join([f.path for f in ctx.files.extra_values]),
+            values_yaml.path,
+        ))
+
+    cmds.extend([
+        "cat - >> {} <<EOF".format(values_yaml.path),
         "### Generated by app_chart ###",
         "images:",
-    ]
+    ])
+
     jq_bin = ctx.toolchains["@aspect_bazel_lib//lib:jq_toolchain_type"].jqinfo.bin
 
     images = ctx.attr.images or {}
@@ -39,7 +53,7 @@ def _impl(ctx):
     ctx.actions.run_shell(
         tools = [jq_bin],
         outputs = [values_yaml],
-        inputs = ctx.files.values + source_digests,
+        inputs = values_files + source_digests,
         command = "\n".join(cmds),
         toolchain = None,
     )
@@ -71,7 +85,14 @@ _app_chart_backend = rule(
         ),
         "values": attr.label(
             allow_single_file = True,
-            doc = "The values.yaml file.",
+            doc = "Override the default values.yaml file.",
+        ),
+        "extra_values": attr.label_list(
+            allow_empty = True,
+            allow_files = True,
+            default = [],
+            doc = "Extra values files to append to values.yaml. " +
+              "Use this if you only want to add additional values without changing the defaults.",
         ),
         "templates": attr.label_list(
             allow_empty = True,
@@ -107,6 +128,7 @@ _app_chart_backend = rule(
 def app_chart(
         name,
         values = None,
+        extra_values = None,
         extra_templates = None,
         files = None,
         images = None,
@@ -122,7 +144,9 @@ def app_chart(
     Args:
       name: string. Must be in the format {app}-{chart}, where chart is
         robot, cloud, or cloud-per-robot.
-      values: file. The values.yaml file.
+      values: file. Override the default values.yaml file.
+      extra_values: list of files. Extra values files to append to values.yaml.
+        Use this if you only want to add additional values without changing the defaults.
       extra_templates: list of files. Extra files for the chart's templates/ directory.
       files: list of files. Extra non-template files for the chart's files/ directory.
       images: dict. Images referenced by the chart.
@@ -149,6 +173,7 @@ def app_chart(
         name = name,
         chart = chart,
         values = values,
+        extra_values = extra_values,
         templates = native.glob([chart + "/*.yaml"], allow_empty = True) + (extra_templates or []),
         files = files,
         images = reversed_images,

src/app_charts/akri/BUILD.bazel

@@ -21,7 +21,7 @@ app_chart(
     files = [
         ":akri-chart.robot",
     ],
-    values = "values-robot.yaml",
+    extra_values = ["values-robot.yaml"],
 )
 
 app(

src/app_charts/akri/values-robot.yaml

@@ -1,6 +1,3 @@
-domain: "example.com"
-project: "my-gcp-project"
-registry: "gcr.io/my-gcp-project"
 robots: []
 
 udev:

src/app_charts/base/BUILD.bazel

@@ -64,7 +64,7 @@ app_chart(
         "metadata-server": "//src/go/cmd/metadata-server:metadata-server-image",
         "chart-assignment-controller": "//src/go/cmd/chart-assignment-controller:chart-assignment-controller-image",
     },
-    values = "values-robot.yaml",
+    extra_values = ["values-robot.yaml"],
     visibility = ["//visibility:public"],
 )
 

src/app_charts/base/values-robot.yaml

@@ -1,8 +1,3 @@
-domain: "example.com"
-project: "my-gcp-project"
-deploy_environment: "GCP"
-registry: "gcr.io/my-gcp-project"
-
 # Setting app_management to "false" will remove layer 2 (app-rollout/chart-assignment-controller, etc).
 app_management: "true"
 

src/app_charts/k8s-relay/BUILD.bazel

@@ -4,13 +4,13 @@ load("//bazel:app_chart.bzl", "app_chart")
 app_chart(
     name = "k8s-relay-cloud",
     images = {"http-relay-server": "//src/go/cmd/http-relay-server:http-relay-server-image"},
-    values = "values-cloud.yaml",
+    extra_values = ["values-cloud.yaml"],
 )
 
 app_chart(
     name = "k8s-relay-robot",
     images = {"http-relay-client": "//src/go/cmd/http-relay-client:http-relay-client-image"},
-    values = "values-robot.yaml"
+    extra_values = ["values-robot.yaml"],
 )
 
 app(

src/app_charts/k8s-relay/values-cloud.yaml

@@ -1,8 +1,3 @@
-domain: "example.com"
-project: "my-gcp-project"
-registry: "gcr.io/my-gcp-project"
-robots: []
-
 # MetricRelabelConfigs to apply to samples after scraping, but before ingestion.
 prometheus:
   serviceMonitor:

src/app_charts/platform-apps/BUILD.bazel

@@ -5,6 +5,5 @@ app_chart(
     extra_templates = [
         "//src/app_charts:app_resources",
     ],
-    values = "values.yaml",
     visibility = ["//visibility:public"],
 )

src/app_charts/prometheus/BUILD.bazel

@@ -35,7 +35,7 @@ app_chart(
     images = {
         "http-relay-server": "//src/go/cmd/http-relay-server:http-relay-server-image",
     },
-    values = "values-cloud.yaml",
+    extra_values = ["values-cloud.yaml"],
 )
 
 app_chart(

src/app_charts/prometheus/values-cloud.yaml

@@ -1,8 +1,3 @@
-domain: "example.com"
-project: "my-gcp-project"
-registry: "gcr.io/my-gcp-project"
-robots: []
-
 # The default requests/limits are sufficient for small deployments with a few
 # robots. For a large deployment with ~30 robots, you might need ~2CPU and
 # ~12Gi mem.

src/app_charts/token-vendor/BUILD.bazel

@@ -9,7 +9,7 @@ app_chart(
     images = {
         "token-vendor-go": "//src/go/cmd/token-vendor:token-vendor-image",
     },
-    values = "values-cloud.yaml",
+    extra_values = ["values-cloud.yaml"],
 )
 
 app(

src/app_charts/token-vendor/values-cloud.yaml

@@ -1,12 +1,3 @@
-domain: "example.com"
-project: "my-gcp-project"
-deploy_environment: "GCP"
-registry: "gcr.io/my-gcp-project"
-robots: []
-region: example-gcp-region
-# Token Vendor feature flags
-use_tv_k8s_verbose: false
-
 token_vendor:
   resources:
     requests: