Macro up worker in skeleton (#330)

skeleton/worker/BUILD.bazel

@@ -1,6 +1,5 @@
 load("@rules_python//python:defs.bzl", "py_binary")
-load("//tools/build_rules:cross_platform_image.bzl", "cross_platform_image")
-load("//tools/build_rules:py_layer.bzl", "py_oci_image")
+load("//tools/build_rules/worker:defs.bzl", "worker")
 
 py_binary(
     name = "binary",
@@ -11,44 +10,9 @@ py_binary(
     deps = ["//skeleton:config_py"],
 )
 
-py_oci_image(
-    name = "base_image",
-    base = "@python3_image",
-    binaries = [
-        "//scripts:wait_for_postgres",
-        ":binary",
-    ],
-    cmd = [
-        "/" + package_name() + "/binary",
-    ],
-    entrypoint = [
-        "/scripts/wait_for_postgres",
-    ],
-    env = {
-        "FLASK_APP": "app.py",
-        "FLASK_DEBUG": "True",
-        "API_PORT": "5000",
-        "FRONTEND_PROTOCOL": "http",
-        "FRONTEND_HOST": "frontend",
-        "FRONTEND_PORT": "5001",
-        "DB_HOST": "pg",
-        "DB_USERNAME": "admin",
-        "DB_PASSWORD": "development",
-        "DATABASE_NAME": "api_development",
-        "FITBIT_CLIENT_ID": "testing",
-        "FITBIT_CLIENT_SECRET": "testing",
-        "FITBIT_VERIFICATION_CODE": "testing",
-        "FLASK_SECRET_KEY": "testing",
-    },
-    tags = ["manual"],
-)
-
-# $ bazel run //skeleton/worker:image_tarball
-# $ docker run --rm shaldengeki/skeleton-worker:latest
-cross_platform_image(
-    name = "image",
-    image = ":base_image",
+worker(
+    name = "worker",
+    binary = ":binary",
+    docker_hub_repository = "docker.io/shaldengeki/skeleton-worker",
     repo_tags = ["shaldengeki/skeleton-worker:latest"],
-    repository = "docker.io/shaldengeki/skeleton-worker",
-    visibility = ["//skeleton/worker:__subpackages__"],
 )

tools/build_rules/worker/defs.bzl

@@ -0,0 +1,9 @@
+"""
+defs.bzl: public interfaces for worker rules.
+
+You should import rules exposed here.
+"""
+
+load("//tools/build_rules/worker:worker.bzl", _worker = "worker")
+
+worker = _worker

tools/build_rules/worker/worker.bzl

@@ -0,0 +1,78 @@
+"""
+
+worker.bzl: Defines the standard worker application used across the monorepo.
+
+"""
+
+load("//tools/build_rules:cross_platform_image.bzl", "cross_platform_image")
+load("//tools/build_rules:py_layer.bzl", "py_oci_image")
+
+def worker(
+        name,
+        binary,
+        repo_tags,
+        docker_hub_repository,
+        env = None,
+        visibility = None):
+    """
+    Defines the standard worker application, including container images.
+
+    Args:
+        name (str): Name to use as a prefix to generated rules.
+        binary (Label): py_binary target that should be the entrypoint of the worker.
+        repo_tags (list[str]): List of tags to apply to the container. See cross_platform_image.
+        docker_hub_repository (str): URL of the dockerhub repository to push to. See cross_platform_image.
+        env (dict[str, str]): Additional environment variables to set in the Python image. See py_oci_image.
+        visibility: The default visibility to set on the generated rules. Defaults to public.
+    """
+
+    binary = Label(binary)
+
+    if env == None:
+        env = {}
+
+    all_env = {
+        "FLASK_APP": "app.py",
+        "FLASK_DEBUG": "True",
+        "API_PORT": "5000",
+        "FRONTEND_PROTOCOL": "http",
+        "FRONTEND_HOST": "frontend",
+        "FRONTEND_PORT": "5001",
+        "DB_HOST": "pg",
+        "DB_USERNAME": "admin",
+        "DB_PASSWORD": "development",
+        "DATABASE_NAME": "api_development",
+        "FLASK_SECRET_KEY": "testing",
+    }
+    all_env.update(env)
+
+    if visibility == None:
+        visibility = ["//visibility:public"]
+
+    py_oci_image(
+        name = name + "_base_image",
+        base = "@python3_image",
+        binaries = [
+            "//scripts:wait_for_postgres",
+            binary,
+        ],
+        cmd = [
+            "/" + binary.package + "/" + binary.name,
+        ],
+        entrypoint = [
+            "/scripts/wait_for_postgres",
+        ],
+        env = all_env,
+        visibility = visibility,
+        tags = ["manual"],
+    )
+
+    # $ bazel run //skeleton/worker:worker_image_tarball
+    # $ docker run --rm shaldengeki/skeleton-worker:latest
+    cross_platform_image(
+        name = name + "_image",
+        image = ":base_image",
+        repo_tags = repo_tags,
+        repository = docker_hub_repository,
+        visibility = visibility,
+    )