ARROW-17953: [Archery] Add archery docker info command

dev/archery/archery/docker/cli.py

@@ -16,6 +16,7 @@
 # under the License.
 
 import os
+import sys
 
 import click
 
@@ -289,3 +290,27 @@ def docker_compose_images(obj):
     click.echo('Available images:')
     for image in compose.images():
         click.echo(f' - {image}')
+
+
+@docker.command('info')
+@click.argument('service_name')
+@click.option('--show', '-s', required=False,
+              help="Show only specific docker-compose key. Examples of keys:"
+                   " command, environment, build, dockerfile")
+@click.pass_obj
+def docker_compose_info(obj, service_name, show):
+    """Show docker-compose definition info for service_name.
+
+    SERVICE_NAME is the name of the docker service defined on
+    the docker-compose. Look at `archery docker images` output for names.
+    """
+    compose = obj['compose']
+    try:
+        service = compose.config.raw_config["services"][service_name]
+    except KeyError:
+        click.echo(f'Service name {service_name} could not be found', err=True)
+        sys.exit(1)
+    else:
+        click.echo(f'Service {service_name} docker-compose config:')
+        output = "\n".join(compose.info(service, show))
+        click.echo(output)

dev/archery/archery/docker/core.py

@@ -95,12 +95,12 @@ def _read_config(self, config_path, compose_bin):
         """
         yaml = YAML()
         with config_path.open() as fp:
-            config = yaml.load(fp)
+            self.raw_config = yaml.load(fp)
 
-        services = config['services'].keys()
-        self.hierarchy = dict(flatten(config.get('x-hierarchy', {})))
-        self.limit_presets = config.get('x-limit-presets', {})
-        self.with_gpus = config.get('x-with-gpus', [])
+        services = self.raw_config['services'].keys()
+        self.hierarchy = dict(flatten(self.raw_config.get('x-hierarchy', {})))
+        self.limit_presets = self.raw_config.get('x-limit-presets', {})
+        self.with_gpus = self.raw_config.get('x-with-gpus', [])
         nodes = self.hierarchy.keys()
         errors = []
 
@@ -417,3 +417,22 @@ def _push(service):
 
     def images(self):
         return sorted(self.config.hierarchy.keys())
+
+    def info(self, key_name, filters=None, prefix=' '):
+        output = []
+        for key, value in key_name.items():
+            if hasattr(value, 'items'):
+                temp_filters = filters
+                if key == filters or filters is None:
+                    output.append(f'{prefix} {key}')
+                    # Keep showing this specific key
+                    # as parent matched filter
+                    temp_filters = None
+                output.extend(self.info(value, temp_filters, prefix + "  "))
+            else:
+                if key == filters or filters is None:
+                    output.append(
+                        f'{prefix} {key}: ' +
+                        f'{value if value is not None else "<inherited>"}'
+                    )
+        return output

dev/archery/archery/docker/tests/test_docker.py

@@ -114,6 +114,11 @@
 arrow_compose_yml = """
 version: '3.5'
 
+x-sccache: &sccache
+  AWS_ACCESS_KEY_ID:
+  AWS_SECRET_ACCESS_KEY:
+  SCCACHE_BUCKET:
+
 x-with-gpus:
   - ubuntu-cuda
 
@@ -162,6 +167,8 @@
     image: org/ubuntu-cpp-cmake32
   ubuntu-c-glib:
     image: org/ubuntu-c-glib
+    environment:
+      <<: [*sccache]
   ubuntu-ruby:
     image: org/ubuntu-ruby
   ubuntu-cuda:
@@ -529,3 +536,39 @@ def test_listing_images(arrow_compose_path):
         'ubuntu-cuda',
         'ubuntu-ruby',
     ]
+
+
+def test_service_info(arrow_compose_path):
+    compose = DockerCompose(arrow_compose_path)
+    service = compose.config.raw_config["services"]["conda-cpp"]
+    assert compose.info(service) == [
+        "  image: org/conda-cpp",
+        "  build",
+        "    context: .",
+        "    dockerfile: ci/docker/conda-cpp.dockerfile"
+    ]
+
+
+def test_service_info_filters(arrow_compose_path):
+    compose = DockerCompose(arrow_compose_path)
+    service = compose.config.raw_config["services"]["conda-cpp"]
+    assert compose.info(service, filters="dockerfile") == [
+        "    dockerfile: ci/docker/conda-cpp.dockerfile"
+    ]
+
+
+def test_service_info_non_existing_filters(arrow_compose_path):
+    compose = DockerCompose(arrow_compose_path)
+    service = compose.config.raw_config["services"]["conda-cpp"]
+    assert compose.info(service, filters="non-existing") == []
+
+
+def test_service_info_inherited_env(arrow_compose_path):
+    compose = DockerCompose(arrow_compose_path)
+    service = compose.config.raw_config["services"]["ubuntu-c-glib"]
+    assert compose.info(service, filters="environment") == [
+        "  environment",
+        "    AWS_ACCESS_KEY_ID: <inherited>",
+        "    AWS_SECRET_ACCESS_KEY: <inherited>",
+        "    SCCACHE_BUCKET: <inherited>"
+    ]