Add support for build arguments

compose/config/config.py

@@ -2,6 +2,7 @@
 from __future__ import unicode_literals
 
 import codecs
+import functools
 import logging
 import operator
 import os
@@ -437,6 +438,11 @@ def resolve_environment(service_dict):
     return dict(resolve_env_var(k, v) for k, v in six.iteritems(env))
 
 
+def resolve_build_args(build):
+    args = parse_build_arguments(build.get('args'))
+    return dict(resolve_env_var(k, v) for k, v in six.iteritems(args))
+
+
 def validate_extended_service_dict(service_dict, filename, service):
     error_prefix = "Cannot extend service '%s' in %s:" % (service, filename)
 
@@ -474,12 +480,16 @@ def process_service(service_config):
             for path in to_list(service_dict['env_file'])
         ]
 
+    if 'build' in service_dict:
+        if isinstance(service_dict['build'], six.string_types):
+            service_dict['build'] = resolve_build_path(working_dir, service_dict['build'])
+        elif isinstance(service_dict['build'], dict) and 'context' in service_dict['build']:
+            path = service_dict['build']['context']
+            service_dict['build']['context'] = resolve_build_path(working_dir, path)
+
     if 'volumes' in service_dict and service_dict.get('volume_driver') is None:
         service_dict['volumes'] = resolve_volume_paths(working_dir, service_dict)
 
-    if 'build' in service_dict:
-        service_dict['build'] = resolve_build_path(working_dir, service_dict['build'])
-
     if 'labels' in service_dict:
         service_dict['labels'] = parse_labels(service_dict['labels'])
 
@@ -515,6 +525,8 @@ def finalize_service(service_config):
     if 'restart' in service_dict:
         service_dict['restart'] = parse_restart_spec(service_dict['restart'])
 
+    normalize_build(service_dict, service_config.working_dir)
+
     return normalize_v1_service_format(service_dict)
 
 
@@ -579,10 +591,31 @@ def merge_mapping(mapping, parse_func):
 
     if version == 1:
         legacy_v1_merge_image_or_build(d, base, override)
+    else:
+        merge_build(d, base, override)
 
     return d
 
 
+def merge_build(output, base, override):
+    build = {}
+
+    if 'build' in base:
+        if isinstance(base['build'], six.string_types):
+            build['context'] = base['build']
+        else:
+            build.update(base['build'])
+
+    if 'build' in override:
+        if isinstance(override['build'], six.string_types):
+            build['context'] = override['build']
+        else:
+            build.update(override['build'])
+
+    if build:
+        output['build'] = build
+
+
 def legacy_v1_merge_image_or_build(output, base, override):
     output.pop('image', None)
     output.pop('build', None)
@@ -602,29 +635,41 @@ def merge_environment(base, override):
     return env
 
 
-def parse_environment(environment):
-    if not environment:
+def split_env(env):
+    if isinstance(env, six.binary_type):
+        env = env.decode('utf-8', 'replace')
+    if '=' in env:
+        return env.split('=', 1)
+    else:
+        return env, None
+
+
+def split_label(label):
+    if '=' in label:
+        return label.split('=', 1)
+    else:
+        return label, ''
+
+
+def parse_dict_or_list(split_func, type_name, arguments):
+    if not arguments:
         return {}
 
-    if isinstance(environment, list):
-        return dict(split_env(e) for e in environment)
+    if isinstance(arguments, list):
+        return dict(split_func(e) for e in arguments)
 
-    if isinstance(environment, dict):
-        return dict(environment)
+    if isinstance(arguments, dict):
+        return dict(arguments)
 
     raise ConfigurationError(
-        "environment \"%s\" must be a list or mapping," %
-        environment
+        "%s \"%s\" must be a list or mapping," %
+        (type_name, arguments)
     )
 
 
-def split_env(env):
-    if isinstance(env, six.binary_type):
-        env = env.decode('utf-8', 'replace')
-    if '=' in env:
-        return env.split('=', 1)
-    else:
-        return env, None
+parse_build_arguments = functools.partial(parse_dict_or_list, split_env, 'build arguments')
+parse_environment = functools.partial(parse_dict_or_list, split_env, 'environment')
+parse_labels = functools.partial(parse_dict_or_list, split_label, 'labels')
 
 
 def resolve_env_var(key, val):
@@ -670,6 +715,26 @@ def resolve_volume_path(working_dir, volume):
         return container_path
 
 
+def normalize_build(service_dict, working_dir):
+    build = {}
+
+    # supported in V1 only
+    if 'dockerfile' in service_dict:
+        build['dockerfile'] = service_dict.pop('dockerfile')
+
+    if 'build' in service_dict:
+        # Shortcut where specifying a string is treated as the build context
+        if isinstance(service_dict['build'], six.string_types):
+            build['context'] = service_dict.pop('build')
+        else:
+            build.update(service_dict['build'])
+            if 'args' in build:
+                build['args'] = resolve_build_args(build)
+
+    if build:
+        service_dict['build'] = build
+
+
 def resolve_build_path(working_dir, build_path):
     if is_url(build_path):
         return build_path
@@ -682,7 +747,13 @@ def is_url(build_path):
 
 def validate_paths(service_dict):
     if 'build' in service_dict:
-        build_path = service_dict['build']
+        build = service_dict.get('build', {})
+
+        if isinstance(build, six.string_types):
+            build_path = build
+        elif isinstance(build, dict) and 'context' in build:
+            build_path = build['context']
+
         if (
             not is_url(build_path) and
             (not os.path.exists(build_path) or not os.access(build_path, os.R_OK))
@@ -737,24 +808,6 @@ def join_path_mapping(pair):
         return ":".join((host, container))
 
 
-def parse_labels(labels):
-    if not labels:
-        return {}
-
-    if isinstance(labels, list):
-        return dict(split_label(e) for e in labels)
-
-    if isinstance(labels, dict):
-        return dict(labels)
-
-
-def split_label(label):
-    if '=' in label:
-        return label.split('=', 1)
-    else:
-        return label, ''
-
-
 def parse_ulimits(ulimits):
     if not ulimits:
         return {}

compose/config/service_schema_v2.json

@@ -15,7 +15,20 @@
       "type": "object",
 
       "properties": {
-        "build": {"type": "string"},
+        "build": {
+          "oneOf": [
+            {"type": "string"},
+            {
+              "type": "object",
+              "properties": {
+                "context": {"type": "string"},
+                "dockerfile": {"type": "string"},
+                "args": {"$ref": "#/definitions/list_or_dict"}
+              },
+              "additionalProperties": false
+            }
+          ]
+        },
         "cap_add": {"type": "array", "items": {"type": "string"}, "uniqueItems": true},
         "cap_drop": {"type": "array", "items": {"type": "string"}, "uniqueItems": true},
         "cgroup_parent": {"type": "string"},

compose/config/validation.py

@@ -151,18 +151,29 @@ def handle_error_for_schema_with_id(error, service_name):
             VALID_NAME_CHARS)
 
     if schema_id == '#/definitions/constraints':
+        # Build context could in 'build' or 'build.context' and dockerfile could be
+        # in 'dockerfile' or 'build.dockerfile'
+        context = False
+        dockerfile = 'dockerfile' in error.instance
+        if 'build' in error.instance:
+            if isinstance(error.instance['build'], six.string_types):
+                context = True
+            else:
+                context = 'context' in error.instance['build']
+                dockerfile = dockerfile or 'dockerfile' in error.instance['build']
+
         # TODO: only applies to v1
-        if 'image' in error.instance and 'build' in error.instance:
+        if 'image' in error.instance and context:
             return (
                 "Service '{}' has both an image and build path specified. "
                 "A service can either be built to image or use an existing "
                 "image, not both.".format(service_name))
-        if 'image' not in error.instance and 'build' not in error.instance:
+        if 'image' not in error.instance and not context:
             return (
                 "Service '{}' has neither an image nor a build path "
                 "specified. At least one must be provided.".format(service_name))
         # TODO: only applies to v1
-        if 'image' in error.instance and 'dockerfile' in error.instance:
+        if 'image' in error.instance and dockerfile:
             return (
                 "Service '{}' has both an image and alternate Dockerfile. "
                 "A service can either be built to image or use an existing "

compose/service.py

@@ -619,7 +619,8 @@ def _get_container_host_config(self, override_options, one_off=False):
     def build(self, no_cache=False, pull=False, force_rm=False):
         log.info('Building %s' % self.name)
 
-        path = self.options['build']
+        build_opts = self.options.get('build', {})
+        path = build_opts.get('context')
         # python2 os.path() doesn't support unicode, so we need to encode it to
         # a byte string
         if not six.PY3:
@@ -633,7 +634,8 @@ def build(self, no_cache=False, pull=False, force_rm=False):
             forcerm=force_rm,
             pull=pull,
             nocache=no_cache,
-            dockerfile=self.options.get('dockerfile', None),
+            dockerfile=build_opts.get('dockerfile', None),
+            buildargs=build_opts.get('args', None),
         )
 
         try:

docs/compose-file.md

@@ -37,7 +37,8 @@ those files, all the [services](#service-configuration-reference) are declared
 at the root of the document.
 
 Version 1 files do not support the declaration of
-named [volumes](#volume-configuration-reference)
+named [volumes](#volume-configuration-reference) or
+[build arguments](#args).
 
 Example:
 
@@ -89,6 +90,30 @@ definition.
 
 ### build
 
+Configuration options that are applied at build time.
+
+In version 1 this must be given as a string representing the context.
+
+  build: .
+
+In version 2 this can alternatively be given as an object with extra options.
+
+  version: 2
+  services:
+    web:
+      build: .
+
+    version: 2
+    services:
+      web:
+        build:
+          context: .
+          dockerfile: Dockerfile-alternate
+          args:
+            buildno: 1
+
+#### context
+
 Either a path to a directory containing a Dockerfile, or a url to a git repository.
 
 When the value supplied is a relative path, it is interpreted as relative to the
@@ -99,9 +124,46 @@ Compose will build and tag it with a generated name, and use that image thereaft
 
     build: /path/to/build/dir
 
-Using `build` together with `image` is not allowed. Attempting to do so results in
+    build:
+      context: /path/to/build/dir
+
+Using `context` together with `image` is not allowed. Attempting to do so results in
 an error.
 
+#### dockerfile
+
+Alternate Dockerfile.
+
+Compose will use an alternate file to build with. A build path must also be
+specified using the `build` key.
+
+    build:
+      context: /path/to/build/dir
+      dockerfile: Dockerfile-alternate
+
+Using `dockerfile` together with `image` is not allowed. Attempting to do so results in an error.
+
+#### args
+
+Add build arguments. You can use either an array or a dictionary. Any
+boolean values; true, false, yes, no, need to be enclosed in quotes to ensure
+they are not converted to True or False by the YML parser.
+
+Build arguments with only a key are resolved to their environment value on the
+machine Compose is running on.
+
+> **Note:** Introduced in version 2 of the compose file format.
+
+    build:
+      args:
+        buildno: 1
+        user: someuser
+
+    build:
+      args:
+        - buildno=1
+        - user=someuser
+
 ### cap_add, cap_drop
 
 Add or drop container capabilities.
@@ -162,18 +224,6 @@ Custom DNS search domains. Can be a single value or a list.
       - dc1.example.com
       - dc2.example.com
 
-### dockerfile
-
-Alternate Dockerfile.
-
-Compose will use an alternate file to build with. A build path must also be
-specified using the `build` key.
-
-    build: /path/to/build/dir
-    dockerfile: Dockerfile-alternate
-
-Using `dockerfile` together with `image` is not allowed. Attempting to do so results in an error.
-
 ### env_file
 
 Add environment variables from a file. Can be a single value or a list.