Squashed commit of the following:

commit 7393c6a
Author: Feike Steenbergen <feikesteenbergen@gmail.com>
Initial bootstrapping of patronicli, to start work on issue #44

patroni/cli.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+'''
+Patroni Command Line Client
+'''
+
+import click
+import os
+import yaml
+import logging
+
+# from patroni.dcs import AbstractDCS, Cluster, Failover, Leader, Member
+
+CONFIG_DIR_PATH = click.get_app_dir('patroni')
+CONFIG_FILE_PATH = os.path.join(CONFIG_DIR_PATH, 'patronicli.yaml')
+LOGLEVEL = 'DEBUG'
+
+
+def load_config(path):
+    logging.debug('Loading configuration from file {}'.format(path))
+    config = None
+    try:
+        with open(path, 'rb') as fd:
+            config = yaml.safe_load(fd)
+    except:
+        logging.exception('Could not load configuration file')
+    return config or {}
+
+
+def store_config(config, path):
+    dir_path = os.path.dirname(path)
+    if dir_path:
+        if not os.path.isdir(dir_path):
+            os.makedirs(dir_path)
+    with open(path, 'w') as fd:
+        yaml.dump(config, fd)
+
+
+@click.group()
+@click.option('--config-file', '-c', help='Use alternative configuration file',
+              default=CONFIG_FILE_PATH)
+@click.pass_context
+def cli(ctx, config_file):
+    logging.basicConfig(format='%(asctime)s - %(levelname)s - %(message)s', level=LOGLEVEL)
+    ctx.obj = load_config(CONFIG_FILE_PATH)
+
+
+@cli.command('list')
+@click.pass_obj
+def list_haclusters(obj):
+    pass

patronicli.py

@@ -0,0 +1,5 @@
+#!/usr/bin/env python
+from patroni.cli import cli
+
+if __name__ == '__main__':
+    cli()

requirements-py2.txt

@@ -7,3 +7,4 @@ requests
 six >= 1.7
 kazoo>=2.2.1
 python-etcd>=0.4.1
+click

requirements-py3.txt

@@ -7,3 +7,4 @@ requests
 six
 kazoo>=2.2.1
 python-etcd>=0.4.1
+click

tests/test_cli.py

@@ -0,0 +1,37 @@
+import os
+import pytest
+
+from click.testing import CliRunner
+from patroni.cli import cli, list_haclusters, store_config, load_config
+
+CONFIG_FILE_PATH="./test-cli.yaml"
+
+def test_rw_config():
+    runner = CliRunner()
+    with runner.isolated_filesystem():
+        os.mkdir(CONFIG_FILE_PATH)
+        with pytest.raises(Exception):
+            result = load_config(CONFIG_FILE_PATH)
+            assert 'Could not load configuration file' in result.output
+
+        with pytest.raises(Exception):
+            store_config(config, CONFIG_FILE_PATH)
+        os.rmdir(CONFIG_FILE_PATH)
+
+    config = "a:b"
+    store_config(config, "abc/CONFIG_FILE_PATH")
+    load_config(CONFIG_FILE_PATH)
+
+def test_cli():
+    runner = CliRunner()
+
+    runner.invoke(cli, ['list'])
+
+    result = runner.invoke(cli, ['--help'])
+    assert 'Usage:' in result.output
+
+def test_list_hacluster():
+    runner = CliRunner()
+
+    result = runner.invoke(list_haclusters)
+