If no command is specified, print collected data as json

os_collect_config/collect.py

@@ -101,6 +101,9 @@ def __main__():
             logger.info("Executing %s" % CONF.command)
             subprocess.call(CONF.command, env=env, shell=True)
             commit_cache('ec2')
+    else:
+        content = {'ec2': ec2_content}
+        print json.dumps(content, indent=1)
 
 
 if __name__ == '__main__':

os_collect_config/tests/test_collect.py

@@ -18,6 +18,7 @@ import json
 import os
 from oslo.config import cfg
 import testtools
+from testtools import matchers
 
 from os_collect_config import collect
 from os_collect_config.tests import test_ec2
@@ -70,6 +71,22 @@ class TestCollect(testtools.TestCase):
 
         self.assertTrue(self.called_fake_call)
 
+    def test_main_no_command(self):
+        fake_args = [
+            'os-collect-config',
+            '--config-file',
+            '/dev/null',
+        ]
+        self.useFixture(
+            fixtures.MonkeyPatch('sys.argv', fake_args))
+        output = self.useFixture(fixtures.ByteStream('stdout'))
+        self.useFixture(
+            fixtures.MonkeyPatch('sys.stdout', output.stream))
+        collect.__main__()
+        out_struct = json.loads(output.stream.getvalue())
+        self.assertThat(out_struct, matchers.IsInstance(dict))
+        self.assertIn('ec2', out_struct)
+
 
 class TestConf(testtools.TestCase):
     def test_setup_conf(self):