Allow launcher in nodejs

.gitignore

@@ -53,3 +53,6 @@ bazel-testlogs
 
 # Npm packages
 node_modules
+
+# JetBrains garbage
+.idea/

README.md

@@ -613,11 +613,13 @@ nodejs_image(
     name = "nodejs_image",
     entry_point = "@your_workspace//path/to:file.js",
     # npm deps will be put into their own layer
-    data = [":file.js", "@npm//some-npm-dep"],
+    data = [":file.js", "@npm//some-npm-dep"],    
     ...
 )
 ```
 
+`nodejs_image` also supports the `launcher` and `launcher_args` attributes which are passed to `container_image` and used to prefix the image's `entry_point`.
+
 If you need to modify somehow the container produced by
 `nodejs_image` (e.g., `env`, `symlink`), see note above in
 <a href=#overview-1>Language Rules Overview</a> about how to do this

nodejs/image.bzl

@@ -115,6 +115,8 @@ def nodejs_image(
         data = [],
         layers = [],
         binary = None,
+        launcher = None,
+        launcher_args = None,
         **kwargs):
     """Constructs a container image wrapping a nodejs_binary target.
 
@@ -125,6 +127,8 @@ def nodejs_image(
     layers: Augments "deps" with dependencies that should be put into
            their own layers.
     binary: An alternative binary target to use instead of generating one.
+    launcher: The container_image launcher to set.
+    launcher_args: The args for the container_image launcher.
     **kwargs: See nodejs_binary.
   """
 
@@ -168,4 +172,6 @@ def nodejs_image(
         args = kwargs.get("args"),
         data = data,
         testonly = kwargs.get("testonly"),
+        launcher = launcher,
+        launcher_args = launcher_args,
     )

run-bazel-in-docker.sh

@@ -0,0 +1,15 @@
+# Runs bazel in a docker container, with this repository's workspace mounted in its file system.
+# This is useful because rules_docker assumes the host environment is linux, and tests will fail on other environments.
+# Running bazel in docker is slower, but allows for the build and tests to execute on non-linux environments.
+
+mkdir -p /tmp/build_output/
+# -e USER="$(id -u)" \
+# -u="$(id -u)" \
+docker run \
+  -v "$PWD":/workspace \
+  -v /tmp/build_output:/tmp/build_output \
+  -v /var/run/docker.sock:/var/run/docker.sock \
+  -w /workspace \
+  l.gcr.io/google/bazel:latest \
+  --output_user_root=/tmp/build_output \
+  "$@"

tests/container/nodejs/BUILD

@@ -33,6 +33,40 @@ nodejs_image(
     entry_point = "@io_bazel_rules_docker//testdata:nodejs_image.js",
 )
 
+nodejs_image(
+    name = "nodejs_image_with_launcher",
+    args = [
+        "arg0",
+        "arg1",
+    ],
+    data = [
+        "//testdata:nodejs_image.js",
+        "//testdata:nodejs_image_lib",
+        "@npm//jsesc",
+    ],
+    entry_point = "@io_bazel_rules_docker//testdata:nodejs_image.js",
+    launcher = "launcher.sh",
+)
+
+nodejs_image(
+    name = "nodejs_image_with_launcher_args",
+    args = [
+        "arg0",
+        "arg1",
+    ],
+    data = [
+        "//testdata:nodejs_image.js",
+        "//testdata:nodejs_image_lib",
+        "@npm//jsesc",
+    ],
+    entry_point = "@io_bazel_rules_docker//testdata:nodejs_image.js",
+    launcher = "launcher.sh",
+    launcher_args = [
+        "foo",
+        "bar",
+    ],
+)
+
 # Docker Cmd value should be `[""]`.
 nodejs_image(
     name = "nodejs_image_list_with_empty_string_args",
@@ -114,6 +148,18 @@ container_test(
     image = ":nodejs_image",
 )
 
+container_test(
+    name = "nodejs_image_with_launcher_test",
+    configs = ["//tests/container/nodejs/configs:nodejs_image_with_launcher.yaml"],
+    image = ":nodejs_image_with_launcher",
+)
+
+container_test(
+    name = "nodejs_image_with_launcher_args_test",
+    configs = ["//tests/container/nodejs/configs:nodejs_image_with_launcher_args.yaml"],
+    image = ":nodejs_image_with_launcher_args",
+)
+
 container_test(
     name = "nodejs_image_list_with_empty_string_args_test",
     configs = ["//tests/container/nodejs/configs:nodejs_image_list_with_empty_string_args.yaml"],

tests/container/nodejs/configs/nodejs_image_with_launcher.yaml

@@ -0,0 +1,13 @@
+schemaVersion: 2.0.0
+
+metadataTest:
+  cmd: ["arg0", "arg1"]
+  env:
+    - key: PORT
+      value: "8080"
+    - key: DEBIAN_FRONTEND
+      value: "noninteractive"
+    - key: PATH
+      value: "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+  entrypoint: ['/launcher.sh', '/app/tests/container/nodejs/nodejs_image_with_launcher.binary']
+  workdir: "/app/tests/container/nodejs/nodejs_image_with_launcher.binary.runfiles/io_bazel_rules_docker"

tests/container/nodejs/configs/nodejs_image_with_launcher_args.yaml

@@ -0,0 +1,13 @@
+schemaVersion: 2.0.0
+
+metadataTest:
+  cmd: ["arg0", "arg1"]
+  env:
+    - key: PORT
+      value: "8080"
+    - key: DEBIAN_FRONTEND
+      value: "noninteractive"
+    - key: PATH
+      value: "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+  entrypoint: ['/launcher.sh', 'foo', 'bar', '/app/tests/container/nodejs/nodejs_image_with_launcher_args.binary']
+  workdir: "/app/tests/container/nodejs/nodejs_image_with_launcher_args.binary.runfiles/io_bazel_rules_docker"

tests/container/nodejs/launcher.sh

@@ -0,0 +1,5 @@
+# Do something before running CMD
+echo "Do something before running CMD"
+
+# Run whatever entrypoint / cmd args are passed next
+"$@"