Add inventory builder python script

Includes tox support for running unit tests.
Small note added to getting-started guide for using
inventory_builder.py

Also adds manual-only unit test.

.gitignore

@@ -3,6 +3,11 @@
 inventory/vagrant_ansible_inventory
 temp
 .idea
+.tox
+.cache
+*.egg-info
+*.pyc
+*.pyo
 *.tfstate
 *.tfstate.backup
-/ssh-bastion.conf
\ No newline at end of file
+/ssh-bastion.conf

.gitlab-ci.yml

@@ -363,3 +363,12 @@ syntax-check:
   script:
     - ansible-playbook -i inventory/local-tests.cfg -u root -e ansible_ssh_user=root  -b --become-user=root cluster.yml -vvv  --syntax-check
   except: ['triggers']
+
+tox-inventory-builder:
+  stage: unit-tests
+  <<: *job
+  script:
+    - pip install tox
+    - cd contrib/inventory_builder && tox
+  when: manual
+  except: ['triggers']

contrib/inventory_builder/inventory.py

+#!/usr/bin/python3
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Usage: inventory.py ip1 [ip2 ...]
+# Examples: inventory.py 10.10.1.3 10.10.1.4 10.10.1.5
+#
+# Advanced usage:
+# Add another host after initial creation: inventory.py 10.10.1.5
+# Delete a host: inventory.py -10.10.1.3
+# Delete a host by id: inventory.py -node1
+
+from collections import OrderedDict
+try:
+    import configparser
+except ImportError:
+    import ConfigParser as configparser
+
+import os
+import re
+import sys
+
+ROLES = ['kube-master', 'all', 'k8s-cluster:children', 'kube-node', 'etcd']
+PROTECTED_NAMES = ROLES
+AVAILABLE_COMMANDS = ['help', 'print_cfg', 'print_ips']
+_boolean_states = {'1': True, 'yes': True, 'true': True, 'on': True,
+                   '0': False, 'no': False, 'false': False, 'off': False}
+
+
+def get_var_as_bool(name, default):
+    value = os.environ.get(name, '')
+    return _boolean_states.get(value.lower(), default)
+
+CONFIG_FILE = os.environ.get("CONFIG_FILE", "./inventory.cfg")
+DEBUG = get_var_as_bool("DEBUG", True)
+HOST_PREFIX = os.environ.get("HOST_PREFIX", "node")
+
+
+class KargoInventory(object):
+
+    def __init__(self, changed_hosts=None, config_file=None):
+        self.config = configparser.ConfigParser(allow_no_value=True,
+                                                delimiters=('\t', ' '))
+        if config_file:
+            self.config.read(config_file)
+
+        if changed_hosts and changed_hosts[0] in AVAILABLE_COMMANDS:
+            self.parse_command(changed_hosts[0], changed_hosts[1:])
+            sys.exit(0)
+
+        self.ensure_required_groups(ROLES)
+
+        if changed_hosts:
+            self.hosts = self.build_hostnames(changed_hosts)
+            self.purge_invalid_hosts(self.hosts.keys(), PROTECTED_NAMES)
+            self.set_kube_master(list(self.hosts.keys())[:2])
+            self.set_all(self.hosts)
+            self.set_k8s_cluster()
+            self.set_kube_node(self.hosts.keys())
+            self.set_etcd(list(self.hosts.keys())[:3])
+        else:  # Show help if no options
+            self.show_help()
+            sys.exit(0)
+
+        if config_file:
+            with open(config_file, 'w') as f:
+                self.config.write(f)
+
+    def debug(self, msg):
+        if DEBUG:
+            print("DEBUG: {0}".format(msg))
+
+    def get_ip_from_opts(self, optstring):
+        opts = optstring.split(' ')
+        for opt in opts:
+            if '=' not in opt:
+                continue
+            k, v = opt.split('=')
+            if k == "ip":
+                return v
+        raise ValueError("IP parameter not found in options")
+
+    def ensure_required_groups(self, groups):
+        for group in groups:
+            try:
+                self.config.add_section(group)
+            except configparser.DuplicateSectionError:
+                pass
+
+    def get_host_id(self, host):
+        '''Returns integer host ID (without padding) from a given hostname.'''
+        try:
+            short_hostname = host.split('.')[0]
+            return int(re.findall("\d+$", short_hostname)[-1])
+        except IndexError:
+            raise ValueError("Host name must end in an integer")
+
+    def build_hostnames(self, changed_hosts):
+        existing_hosts = OrderedDict()
+        highest_host_id = 0
+        try:
+            for host, opts in self.config.items('all'):
+                existing_hosts[host] = opts
+                host_id = self.get_host_id(host)
+                if host_id > highest_host_id:
+                    highest_host_id = host_id
+        except configparser.NoSectionError:
+            pass
+
+        # FIXME(mattymo): Fix condition where delete then add reuses highest id
+        next_host_id = highest_host_id + 1
+
+        all_hosts = existing_hosts.copy()
+        for host in changed_hosts:
+            if host[0] == "-":
+                realhost = host[1:]
+                if self.exists_hostname(all_hosts, realhost):
+                    self.debug("Marked {0} for deletion.".format(realhost))
+                    all_hosts.pop(realhost)
+                elif self.exists_ip(all_hosts, realhost):
+                    self.debug("Marked {0} for deletion.".format(realhost))
+                    self.delete_host_by_ip(all_hosts, realhost)
+            elif host[0].isdigit():
+                if self.exists_hostname(all_hosts, host):
+                    self.debug("Skipping existing host {0}.".format(host))
+                    continue
+                elif self.exists_ip(all_hosts, host):
+                    self.debug("Skipping existing host {0}.".format(host))
+                    continue
+
+                next_host = "{0}{1}".format(HOST_PREFIX, next_host_id)
+                next_host_id += 1
+                all_hosts[next_host] = "ansible_host={0} ip={1}".format(
+                    host, host)
+            elif host[0].isalpha():
+                raise Exception("Adding hosts by hostname is not supported.")
+
+        return all_hosts
+
+    def exists_hostname(self, existing_hosts, hostname):
+        return hostname in existing_hosts.keys()
+
+    def exists_ip(self, existing_hosts, ip):
+        for host_opts in existing_hosts.values():
+            if ip == self.get_ip_from_opts(host_opts):
+                return True
+        return False
+
+    def delete_host_by_ip(self, existing_hosts, ip):
+        for hostname, host_opts in existing_hosts.items():
+            if ip == self.get_ip_from_opts(host_opts):
+                del existing_hosts[hostname]
+                return
+        raise ValueError("Unable to find host by IP: {0}".format(ip))
+
+    def purge_invalid_hosts(self, hostnames, protected_names=[]):
+        for role in self.config.sections():
+            for host, _ in self.config.items(role):
+                if host not in hostnames and host not in protected_names:
+                    self.debug("Host {0} removed from role {1}".format(host,
+                               role))
+                    self.config.remove_option(role, host)
+
+    def add_host_to_group(self, group, host, opts=""):
+        self.debug("adding host {0} to group {1}".format(host, group))
+        self.config.set(group, host, opts)
+
+    def set_kube_master(self, hosts):
+        for host in hosts:
+            self.add_host_to_group('kube-master', host)
+
+    def set_all(self, hosts):
+        for host, opts in hosts.items():
+            self.add_host_to_group('all', host, opts)
+
+    def set_k8s_cluster(self):
+        self.add_host_to_group('k8s-cluster:children', 'kube-node')
+        self.add_host_to_group('k8s-cluster:children', 'kube-master')
+
+    def set_kube_node(self, hosts):
+        for host in hosts:
+            self.add_host_to_group('kube-node', host)
+
+    def set_etcd(self, hosts):
+        for host in hosts:
+            self.add_host_to_group('etcd', host)
+
+    def parse_command(self, command, args=None):
+        if command == 'help':
+            self.show_help()
+        elif command == 'print_cfg':
+            self.print_config()
+        elif command == 'print_ips':
+            self.print_ips()
+        else:
+            raise Exception("Invalid command specified.")
+
+    def show_help(self):
+        help_text = '''Usage: inventory.py ip1 [ip2 ...]
+Examples: inventory.py 10.10.1.3 10.10.1.4 10.10.1.5
+
+Available commands:
+help - Display this message
+print_cfg - Write inventory file to stdout
+print_ips - Write a space-delimited list of IPs from "all" group
+
+Advanced usage:
+Add another host after initial creation: inventory.py 10.10.1.5
+Delete a host: inventory.py -10.10.1.3
+Delete a host by id: inventory.py -node1'''
+        print(help_text)
+
+    def print_config(self):
+        self.config.write(sys.stdout)
+
+    def print_ips(self):
+        ips = []
+        for host, opts in self.config.items('all'):
+            ips.append(self.get_ip_from_opts(opts))
+        print(' '.join(ips))
+
+
+def main(argv=None):
+    if not argv:
+        argv = sys.argv[1:]
+    KargoInventory(argv, CONFIG_FILE)
+
+if __name__ == "__main__":
+    sys.exit(main())

contrib/inventory_builder/requirements.txt

+configparser>=3.3.0

contrib/inventory_builder/setup.cfg

+[metadata]
+name = kargo-inventory-builder
+version = 0.1

contrib/inventory_builder/setup.py

+# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# THIS FILE IS MANAGED BY THE GLOBAL REQUIREMENTS REPO - DO NOT EDIT
+import setuptools
+
+# In python < 2.7.4, a lazy loading of package `pbr` will break
+# setuptools if some other modules registered functions in `atexit`.
+# solution from: http://bugs.python.org/issue15881#msg170215
+try:
+    import multiprocessing  # noqa
+except ImportError:
+    pass
+
+setuptools.setup(
+    setup_requires=[],
+    pbr=False)

contrib/inventory_builder/test-requirements.txt

+hacking>=0.10.2
+pytest>=2.8.0
+mock>=1.3.0

contrib/inventory_builder/tests/test_inventory.py

+# Copyright 2016 Mirantis, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import mock
+import unittest
+
+from collections import OrderedDict
+import sys
+
+path = "./contrib/inventory_builder/"
+if path not in sys.path:
+    sys.path.append(path)
+
+import inventory
+
+
+class TestInventory(unittest.TestCase):
+    @mock.patch('inventory.sys')
+    def setUp(self, sys_mock):
+        sys_mock.exit = mock.Mock()
+        super(TestInventory, self).setUp()
+        self.data = ['10.90.3.2', '10.90.3.3', '10.90.3.4']
+        self.inv = inventory.KargoInventory()
+
+    def test_get_ip_from_opts(self):
+        optstring = "ansible_host=10.90.3.2 ip=10.90.3.2"
+        expected = "10.90.3.2"
+        result = self.inv.get_ip_from_opts(optstring)
+        self.assertEqual(expected, result)
+
+    def test_get_ip_from_opts_invalid(self):
+        optstring = "notanaddr=value something random!chars:D"
+        self.assertRaisesRegexp(ValueError, "IP parameter not found",
+                                self.inv.get_ip_from_opts, optstring)
+
+    def test_ensure_required_groups(self):
+        groups = ['group1', 'group2']
+        self.inv.ensure_required_groups(groups)
+        for group in groups:
+            self.assertTrue(group in self.inv.config.sections())
+
+    def test_get_host_id(self):
+        hostnames = ['node99', 'no99de01', '01node01', 'node1.domain',
+                     'node3.xyz123.aaa']
+        expected = [99, 1, 1, 1, 3]
+        for hostname, expected in zip(hostnames, expected):
+            result = self.inv.get_host_id(hostname)
+            self.assertEqual(expected, result)
+
+    def test_get_host_id_invalid(self):
+        bad_hostnames = ['node', 'no99de', '01node', 'node.111111']
+        for hostname in bad_hostnames:
+            self.assertRaisesRegexp(ValueError, "Host name must end in an",
+                                    self.inv.get_host_id, hostname)
+
+    def test_build_hostnames_add_one(self):
+        changed_hosts = ['10.90.0.2']
+        expected = OrderedDict([('node1',
+                               'ansible_host=10.90.0.2 ip=10.90.0.2')])
+        result = self.inv.build_hostnames(changed_hosts)
+        self.assertEqual(expected, result)
+
+    def test_build_hostnames_add_duplicate(self):
+        changed_hosts = ['10.90.0.2']
+        expected = OrderedDict([('node1',
+                               'ansible_host=10.90.0.2 ip=10.90.0.2')])
+        self.inv.config['all'] = expected
+        result = self.inv.build_hostnames(changed_hosts)
+        self.assertEqual(expected, result)
+
+    def test_build_hostnames_add_two(self):
+        changed_hosts = ['10.90.0.2', '10.90.0.3']
+        expected = OrderedDict([
+            ('node1', 'ansible_host=10.90.0.2 ip=10.90.0.2'),
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3')])
+        self.inv.config['all'] = OrderedDict()
+        result = self.inv.build_hostnames(changed_hosts)
+        self.assertEqual(expected, result)
+
+    def test_build_hostnames_delete_first(self):
+        changed_hosts = ['-10.90.0.2']
+        existing_hosts = OrderedDict([
+            ('node1', 'ansible_host=10.90.0.2 ip=10.90.0.2'),
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3')])
+        self.inv.config['all'] = existing_hosts
+        expected = OrderedDict([
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3')])
+        result = self.inv.build_hostnames(changed_hosts)
+        self.assertEqual(expected, result)
+
+    def test_exists_hostname_positive(self):
+        hostname = 'node1'
+        expected = True
+        existing_hosts = OrderedDict([
+            ('node1', 'ansible_host=10.90.0.2 ip=10.90.0.2'),
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3')])
+        result = self.inv.exists_hostname(existing_hosts, hostname)
+        self.assertEqual(expected, result)
+
+    def test_exists_hostname_negative(self):
+        hostname = 'node99'
+        expected = False
+        existing_hosts = OrderedDict([
+            ('node1', 'ansible_host=10.90.0.2 ip=10.90.0.2'),
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3')])
+        result = self.inv.exists_hostname(existing_hosts, hostname)
+        self.assertEqual(expected, result)
+
+    def test_exists_ip_positive(self):
+        ip = '10.90.0.2'
+        expected = True
+        existing_hosts = OrderedDict([
+            ('node1', 'ansible_host=10.90.0.2 ip=10.90.0.2'),
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3')])
+        result = self.inv.exists_ip(existing_hosts, ip)
+        self.assertEqual(expected, result)
+
+    def test_exists_ip_negative(self):
+        ip = '10.90.0.200'
+        expected = False
+        existing_hosts = OrderedDict([
+            ('node1', 'ansible_host=10.90.0.2 ip=10.90.0.2'),
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3')])
+        result = self.inv.exists_ip(existing_hosts, ip)
+        self.assertEqual(expected, result)
+
+    def test_delete_host_by_ip_positive(self):
+        ip = '10.90.0.2'
+        expected = OrderedDict([
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3')])
+        existing_hosts = OrderedDict([
+            ('node1', 'ansible_host=10.90.0.2 ip=10.90.0.2'),
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3')])
+        self.inv.delete_host_by_ip(existing_hosts, ip)
+        self.assertEqual(expected, existing_hosts)
+
+    def test_delete_host_by_ip_negative(self):
+        ip = '10.90.0.200'
+        existing_hosts = OrderedDict([
+            ('node1', 'ansible_host=10.90.0.2 ip=10.90.0.2'),
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3')])
+        self.assertRaisesRegexp(ValueError, "Unable to find host",
+                                self.inv.delete_host_by_ip, existing_hosts, ip)
+
+    def test_purge_invalid_hosts(self):
+        proper_hostnames = ['node1', 'node2']
+        bad_host = 'doesnotbelong2'
+        existing_hosts = OrderedDict([
+            ('node1', 'ansible_host=10.90.0.2 ip=10.90.0.2'),
+            ('node2', 'ansible_host=10.90.0.3 ip=10.90.0.3'),
+            ('doesnotbelong2', 'whateveropts=ilike')])
+        self.inv.config['all'] = existing_hosts
+        self.inv.purge_invalid_hosts(proper_hostnames)
+        self.assertTrue(bad_host not in self.inv.config['all'].keys())
+
+    def test_add_host_to_group(self):
+        group = 'etcd'
+        host = 'node1'
+        opts = 'ip=10.90.0.2'
+
+        self.inv.add_host_to_group(group, host, opts)
+        self.assertEqual(self.inv.config[group].get(host), opts)
+
+    def test_set_kube_master(self):
+        group = 'kube-master'
+        host = 'node1'
+
+        self.inv.set_kube_master([host])
+        self.assertTrue(host in self.inv.config[group])
+
+    def test_set_all(self):
+        group = 'all'
+        hosts = OrderedDict([
+            ('node1', 'opt1'),
+            ('node2', 'opt2')])
+
+        self.inv.set_all(hosts)
+        for host, opt in hosts.items():
+            self.assertEqual(self.inv.config[group].get(host), opt)
+
+    def test_set_k8s_cluster(self):
+        group = 'k8s-cluster:children'
+        expected_hosts = ['kube-node', 'kube-master']
+
+        self.inv.set_k8s_cluster()
+        for host in expected_hosts:
+            self.assertTrue(host in self.inv.config[group])
+
+    def test_set_kube_node(self):
+        group = 'kube-node'
+        host = 'node1'
+
+        self.inv.set_kube_node([host])
+        self.assertTrue(host in self.inv.config[group])
+
+    def test_set_etcd(self):
+        group = 'etcd'
+        host = 'node1'
+
+        self.inv.set_etcd([host])
+        self.assertTrue(host in self.inv.config[group])

contrib/inventory_builder/tox.ini

+[tox]
+minversion = 1.6
+skipsdist = True
+envlist = pep8, py27
+
+[testenv]
+whitelist_externals = py.test
+usedevelop = True
+deps =
+    -r{toxinidir}/requirements.txt
+    -r{toxinidir}/test-requirements.txt
+setenv = VIRTUAL_ENV={envdir}
+passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
+commands = py.test -vv #{posargs:./tests}
+
+[testenv:pep8]
+usedevelop = False
+whitelist_externals = bash
+commands =
+    bash -c "find {toxinidir}/* -type f -name '*.py' -print0 | xargs -0 flake8"
+
+[testenv:venv]
+commands = {posargs}
+
+[flake8]
+show-source = true
+builtins = _
+exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg

docs/getting-started.md

@@ -17,3 +17,16 @@ kargo aws --instances 3
 ```
 kargo deploy --aws -u centos -n calico
 ```
+
+Building your own inventory
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Ansible inventory can be stored in 3 formats: YAML, JSON, or inifile. There is
+an example inventory located
+[here](https://github.com/kubernetes-incubator/kargo/blob/master/inventory/inventory.example).
+
+You can use an
+[inventory generator](https://github.com/kubernetes-incubator/kargo/blob/master/contrib/inventory_generator/inventory_generator.py)
+to create or modify an Ansible inventory. Currently, it is limited in
+functionality and is only use for making a basic Kargo cluster, but it does
+support creating large clusters.