Allow jjb to be called as a module

Enable us to do `python -m jenkins_jobs ...`
which avoids the need to install executable in
user path.

Tests cli execution on each supported python version.

Uses default encoding workaround only on
python2, where is needed.

Change-Id: I4cd79fd51a8309d532e0e76723ecfbbda3e1ca6f
Signed-off-by: Sorin Sbarnea <ssbarnea@redhat.com>

jenkins_jobs/__main__.py

@@ -0,0 +1,4 @@
+from jenkins_jobs.cli.entry import main
+
+if __name__ == "__main__":
+    main()

jenkins_jobs/cli/entry.py

@@ -17,7 +17,6 @@ import io
 import os
 import logging
 import platform
-import sys
 
 from stevedore import extension
 import yaml
@@ -27,9 +26,6 @@ from jenkins_jobs.config import JJBConfig
 from jenkins_jobs import utils
 from jenkins_jobs import version
 
-if sys.version_info[0] != 2:
-    from importlib import reload
-
 logging.basicConfig(level=logging.INFO)
 logger = logging.getLogger()
 
@@ -147,14 +143,15 @@ def main():
 
     # utf-8 workaround for avoiding unicode errors in stdout/stderr
     # see https://stackoverflow.com/a/2001767/99834
-    import codecs
     import sys
 
-    reload(sys)
-    sys.setdefaultencoding('utf-8')
-    sys.stdout = codecs.getwriter('utf8')(sys.stdout)
-    sys.stderr = codecs.getwriter('utf8')(sys.stderr)
-    # end of workaround
+    if sys.version_info[0] == 2:
+        import codecs
+        reload(sys)  # noqa
+        sys.setdefaultencoding('utf-8')
+        sys.stdout = codecs.getwriter('utf8')(sys.stdout)
+        sys.stderr = codecs.getwriter('utf8')(sys.stderr)
+        # end of workaround
 
     argv = sys.argv[1:]
     jjb = JenkinsJobs(argv)

tools/test-commands.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+set -exou pipefail
+
+VAL1=$(jenkins-jobs --version 2>&1) || exit 1
+VAL2=$(python -m jenkins_jobs --version 2>&1) || exit 2
+
+# we assure that both calling methods to get the same output
+[ "${VAL1}" == "${VAL2}" ] || exit 3

tox.ini

@@ -18,6 +18,8 @@ deps = -r{toxinidir}/test-requirements.txt
 commands =
     - find . -type f -name "*.pyc" -delete
     - find . -type d -name "__pycache__" -delete
+    # test that we can call jjb using both variants with same results
+    bash {toxinidir}/tools/test-commands.sh
     stestr run --slowest {posargs}
 whitelist_externals =
     bash