Detailed error message when daemon version is too old.

Signed-off-by: Joffrey F <joffrey@docker.com>

compose/cli/main.py

@@ -19,6 +19,7 @@ from ..config import config
 from ..config import ConfigurationError
 from ..config import parse_environment
 from ..config.serialize import serialize_config
+from ..const import API_VERSION_TO_ENGINE_VERSION
 from ..const import DEFAULT_TIMEOUT
 from ..const import HTTP_TIMEOUT
 from ..const import IS_WINDOWS_PLATFORM
@@ -64,7 +65,7 @@ def main():
         log.error("No such command: %s\n\n%s", e.command, commands)
         sys.exit(1)
     except APIError as e:
-        log.error(e.explanation)
+        log_api_error(e)
         sys.exit(1)
     except BuildError as e:
         log.error("Service '%s' failed to build: %s" % (e.service.name, e.reason))
@@ -84,6 +85,22 @@ def main():
         sys.exit(1)
 
 
+def log_api_error(e):
+    if 'client is newer than server' in e.explanation:
+        # we need JSON formatted errors. In the meantime...
+        # TODO: fix this by refactoring project dispatch
+        # http://github.com/docker/compose/pull/2832#commitcomment-15923800
+        client_version = e.explanation.split('client API version: ')[1].split(',')[0]
+        log.error(
+            "The engine version is lesser than the minimum required by "
+            "compose. Your current project requires a Docker Engine of "
+            "version {version} or superior.".format(
+                version=API_VERSION_TO_ENGINE_VERSION[client_version]
+            ))
+    else:
+        log.error(e.explanation)
+
+
 def setup_logging():
     root_logger = logging.getLogger()
     root_logger.addHandler(console_handler)

compose/const.py

@@ -22,3 +22,8 @@ API_VERSIONS = {
     COMPOSEFILE_V1: '1.21',
     COMPOSEFILE_V2_0: '1.22',
 }
+
+API_VERSION_TO_ENGINE_VERSION = {
+    API_VERSIONS[COMPOSEFILE_V1]: '1.9.0',
+    API_VERSIONS[COMPOSEFILE_V2_0]: '1.10.0'
+}