From 89f2bfe4f392b1bb74ab85af01dc95d2d6b47202 Mon Sep 17 00:00:00 2001
From: Gil Raphaelli <g@raphaelli.com>
Date: Tue, 31 Jul 2018 11:54:32 -0400
Subject: [PATCH] add --parallel option to build

Signed-off-by: Gil Raphaelli <g@raphaelli.com>
---
 compose/cli/main.py                           |  2 ++
 compose/project.py                            | 27 +++++++++++++++++--
 tests/acceptance/cli_test.py                  |  7 +++++
 .../build-multiple-composefile/a/Dockerfile   |  4 +++
 .../build-multiple-composefile/b/Dockerfile   |  4 +++
 .../docker-compose.yml                        |  8 ++++++
 6 files changed, 50 insertions(+), 2 deletions(-)
 create mode 100644 tests/fixtures/build-multiple-composefile/a/Dockerfile
 create mode 100644 tests/fixtures/build-multiple-composefile/b/Dockerfile
 create mode 100644 tests/fixtures/build-multiple-composefile/docker-compose.yml

diff --git a/compose/cli/main.py b/compose/cli/main.py
index fa6401412..d224093cb 100644
--- a/compose/cli/main.py
+++ b/compose/cli/main.py
@@ -260,6 +260,7 @@ class TopLevelCommand(object):
             --pull                  Always attempt to pull a newer version of the image.
             -m, --memory MEM        Sets memory limit for the build container.
             --build-arg key=val     Set build-time variables for services.
+            --parallel              Build images in parallel.
         """
         service_names = options['SERVICE']
         build_args = options.get('--build-arg', None)
@@ -280,6 +281,7 @@ class TopLevelCommand(object):
             memory=options.get('--memory'),
             build_args=build_args,
             gzip=options.get('--compress', False),
+            parallel_build=options.get('--parallel', False),
         )
 
     def bundle(self, options):
diff --git a/compose/project.py b/compose/project.py
index 005b7e240..a7ef327e6 100644
--- a/compose/project.py
+++ b/compose/project.py
@@ -372,13 +372,36 @@ class Project(object):
         return containers
 
     def build(self, service_names=None, no_cache=False, pull=False, force_rm=False, memory=None,
-              build_args=None, gzip=False):
+              build_args=None, gzip=False, parallel_build=False):
+
+        services = []
         for service in self.get_services(service_names):
             if service.can_be_built():
-                service.build(no_cache, pull, force_rm, memory, build_args, gzip)
+                services.append(service)
             else:
                 log.info('%s uses an image, skipping' % service.name)
 
+        def build_service(service):
+            service.build(no_cache, pull, force_rm, memory, build_args, gzip)
+
+        if parallel_build:
+            _, errors = parallel.parallel_execute(
+                services,
+                build_service,
+                operator.attrgetter('name'),
+                'Building',
+                limit=5,
+            )
+            if len(errors):
+                combined_errors = '\n'.join([
+                    e.decode('utf-8') if isinstance(e, six.binary_type) else e for e in errors.values()
+                ])
+                raise ProjectError(combined_errors)
+
+        else:
+            for service in services:
+                build_service(service)
+
     def create(
         self,
         service_names=None,
diff --git a/tests/acceptance/cli_test.py b/tests/acceptance/cli_test.py
index 6c6cf32f5..2361a1fbf 100644
--- a/tests/acceptance/cli_test.py
+++ b/tests/acceptance/cli_test.py
@@ -773,6 +773,13 @@ class CLITestCase(DockerClientTestCase):
 
         assert 'does not exist, is not accessible, or is not a valid URL' in result.stderr
 
+    def test_build_parallel(self):
+        self.base_dir = 'tests/fixtures/build-multiple-composefile'
+        result = self.dispatch(['build', '--parallel'])
+        assert 'Successfully tagged build-multiple-composefile_a:latest' in result.stdout
+        assert 'Successfully tagged build-multiple-composefile_b:latest' in result.stdout
+        assert 'Successfully built' in result.stdout
+
     def test_create(self):
         self.dispatch(['create'])
         service = self.project.get_service('simple')
diff --git a/tests/fixtures/build-multiple-composefile/a/Dockerfile b/tests/fixtures/build-multiple-composefile/a/Dockerfile
new file mode 100644
index 000000000..2ba45ce55
--- /dev/null
+++ b/tests/fixtures/build-multiple-composefile/a/Dockerfile
@@ -0,0 +1,4 @@
+
+FROM busybox:latest
+RUN  echo a
+CMD  top
diff --git a/tests/fixtures/build-multiple-composefile/b/Dockerfile b/tests/fixtures/build-multiple-composefile/b/Dockerfile
new file mode 100644
index 000000000..e282e8bbf
--- /dev/null
+++ b/tests/fixtures/build-multiple-composefile/b/Dockerfile
@@ -0,0 +1,4 @@
+
+FROM busybox:latest
+RUN  echo b
+CMD  top
diff --git a/tests/fixtures/build-multiple-composefile/docker-compose.yml b/tests/fixtures/build-multiple-composefile/docker-compose.yml
new file mode 100644
index 000000000..efa70d7e0
--- /dev/null
+++ b/tests/fixtures/build-multiple-composefile/docker-compose.yml
@@ -0,0 +1,8 @@
+
+version: "2"
+
+services:
+  a:
+    build: ./a
+  b:
+    build: ./b