Merge lp:~sinzui/charms/precise/juju-gui/unstable-nagios into lp:~juju-gui/charms/precise/juju-gui/trunk

[Curtis Hovey]

Add nagios-external-master support

This branch merges nagios-external-master support from the stable charm to this unstable charm. Conflicts had to be resolved. in 20-functional.test and in config.yaml.

https://codereview.appspot.com/12942043/

[Curtis Hovey (sinzui)]

Reviewers: mp+180209_code.launchpad.net,

Message:
Please take a look.

Description:
Add nagios-external-master support

This branch merges nagios-external-master support from the stable charm
to this unstable charm. Conflicts had to be resolved. in
20-functional.test and in config.yaml.

https://code.launchpad.net/~sinzui/charms/precise/juju-gui/unstable-nagios/+merge/180209

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/12942043/

Affected files:
   A [revision details]
   M config.yaml
   A files/nrpe-external-master/check-app-access.sh
   M metadata.yaml
   M revision
   A scripts/charmsupport/__init__.py
   A scripts/charmsupport/hookenv.py
   A scripts/charmsupport/nrpe.py
   A scripts/update-nrpe.py
   M tests/20-functional.test

=== modified file 'config.yaml'
--- config.yaml	2013-08-06 10:54:37 +0000
+++ config.yaml	2013-08-14 18:21:07 +0000
@@ -158,7 +158,7 @@
         canvas. This is also known as browse mode.
       - 'minimized': the charmbrowser will be minimized by default, and hidden.
     type: string
-    default: sidebar 
+    default: sidebar
   show-get-juju-button:
     description: |
       There are deployment modes for Juju GUI which are not intended as regular
@@ -173,3 +173,13 @@
       the only server in the future.
     type: boolean
     default: false
+  nagios_context:
+    description: |
+      Used by the nrpe-external-master subordinate charm.
+      A string that will be prepended to instance name to set the host name
+      in nagios. So for instance the hostname would be something like:
+          juju-myservice-0
+      If you're running multiple environments with the same services in them
+      this allows you to differentiate between them.
+    type: string
+    default: "juju"

=== added directory 'files'
=== added directory 'files/nrpe-external-master'
=== added file 'files/nrpe-external-master/check-app-access.sh'
--- files/nrpe-external-master/check-app-access.sh	1970-01-01 00:00:00 +0000
+++ files/nrpe-external-master/check-app-access.sh	2013-08-14 18:21:07 +0000
@@ -0,0 +1,18 @@
+#!/bin/bash
+SITE_CONF='/etc/apache2/sites-enabled/juju-gui'
+ADDRESS='https://127.0.0.1:443/juju-ui/version.js'
+LIFE_SIGN='jujuGuiVersionInfo'
+
+if [[ ! -f $SITE_CONF ]]; then
+    echo Apache is not configured serve juju-gui.
+    exit 2
+fi
+
+match=$(curl -k $ADDRESS | grep "$LIFE_SIGN")
+
+if [[ -n "$match" ]]; then
+    exit 0
+else
+    echo juju-gui did not return content indicating it was loading.
+    exit 2
+fi

=== added symlink 'hooks/nrpe-external-master-relation-changed'
=== target is u'../scripts/update-nrpe.py'
=== modified file 'metadata.yaml'
--- metadata.yaml	2013-06-11 14:13:45 +0000
+++ metadata.yaml	2013-08-14 18:21:07 +0000
@@ -22,3 +22,6 @@
 provides:
   web:
     interface: http
+  nrpe-external-master:
+    interface: nrpe-external-master
+    scope: container

=== modified file 'revision'
--- revision	2013-08-08 14:13:41 +0000
+++ revision	2013-08-14 18:21:07 +0000
@@ -1,1 +1,1 @@
-68
+69

=== added directory 'scripts'
=== added directory 'scripts/charmsupport'
=== added file 'scripts/charmsupport/__init__.py'
=== added file 'scripts/charmsupport/hookenv.py'
--- scripts/charmsupport/hookenv.py	1970-01-01 00:00:00 +0000
+++ scripts/charmsupport/hookenv.py	2013-08-14 18:21:07 +0000
@@ -0,0 +1,150 @@
+"Interactions with the Juju environment"
+# source: 27:lp:charmsupport
+# Copyright 2012 Canonical Ltd.
+#
+# Authors:
+#  Matthew Wedgwood <[e-mail]>
+
+import os
+import json
+import yaml
+import subprocess
+
+CRITICAL = "CRITICAL"
+ERROR = "ERROR"
+WARNING = "WARNING"
+INFO = "INFO"
+DEBUG = "DEBUG"
+def log(message, level=DEBUG):
+    "Write a message to the juju log"
+    subprocess.call( [ 'juju-log', '-l', level, message ] )
+
+class Serializable(object):
+    "Wrapper, an object that can be serialized to yaml or json"
+    def __init__(self, obj):
+        # wrap the object
+        super(Serializable, self).__init__()
+        self._wrapped_obj = obj
+
+    def __getattr__(self, attr):
+        # see if this object has attr
+        if attr in self.__dict__:
+            return getattr(self, attr)
+        # proxy to the wrapped object
+        return self[attr]
+
+    def __getitem__(self, key):
+        return self._wrapped_obj[key]
+
+    def json(self):
+        "Serialize the object to json"
+        return json.dumps(self._wrapped_obj)
+
+    def yaml(self):
+        "Serialize the object to yaml"
+        return yaml.dump(self._wrapped_obj)
+
+def execution_environment():
+    """A convenient bundling of the current execution context"""
+    context = {}
+    context['conf'] = config()
+    context['unit'] = local_unit()
+    context['rel'] = relations_of_type()
+    context['env'] = os.environ
+    return context
+
+def in_relation_hook():
+    "Determine whether we're running in a relation hook"
+    return os.environ.has_key('JUJU_RELATION')
+
+def relation_type():
+    "The scope for the current relation hook"
+    return os.environ['JUJU_RELATION']
+def relation_id():
+    "The relation ID for the current relation hook"
+    return os.environ['JUJU_RELATION_ID']
+def local_unit():
+    "Local unit ID"
+    return os.environ['JUJU_UNIT_NAME']
+def remote_unit():
+    "The remote unit for the current relation hook"
+    return os.environ['JUJU_REMOTE_UNIT']
+
+def config(scope=None):
+    "Juju charm configuration"
+    config_cmd_line = ['config-get']
+    if scope is not None:
+        config_cmd_line.append(scope)
+    config_cmd_line.append('--format=json')
+    try:
+        config_data = json.loads(subprocess.check_output(config_cmd_line))
+    except (ValueError, OSError, subprocess.CalledProcessError) as err:
+        log(str(err), level=ERROR)
+        raise err
+    return Serializable(config_data)
+
+def relation_ids(reltype=None):
+    "A list of relation_ids"
+    reltype = reltype or relation_type()
+    relids = []
+    relid_cmd_line = ['relation-ids', '--format=json', reltype]
+    relids.extend(json.loads(subprocess.check_output(relid_cmd_line)))
+    return relids
+
+def related_units(relid=None):
+    "A list of related units"
+    relid = relid or relation_id()
+    units_cmd_line = ['relation-list', '--format=json', '-r', relid]
+    units = json.loads(subprocess.check_output(units_cmd_line))
+    return units
+
+def relation_for_unit(unit=None):
+    "Get the json represenation of a unit's relation"
+    unit = unit or remote_unit()
+    relation_cmd_line = ['relation-get', '--format=json', '-', unit]
+    try:
+        relation = json.loads(subprocess.check_output(relation_cmd_line))
+    except (ValueError, OSError, subprocess.CalledProcessError), err:
+        log(str(err), level=ERROR)
+        raise err
+    for key in relation:
+        if key.endswith('-list'):
+            relation[key] = relation[key].split()
+    relation['__unit__'] = unit
+    return Serializable(relation)
+
+def relations_for_id(relid=None):
+    "Get relations of a specific relation ID"
+    relation_data = []
+    relid = relid or relation_ids()
+    for unit in related_units(relid):
+        unit_data = relation_for_unit(unit)
+        unit_data['__relid__'] = relid
+        relation_data.append(unit_data)
+    return relation_data
+
+def relations_of_type(reltype=None):
+    "Get relations of a specific type"
+    relation_data = []
+    if in_relation_hook():
+        reltype = reltype or relation_type()
+        for relid in relation_ids(reltype):
+            for relation in relations_for_id(relid):
+                relation['__relid__'] = relid
+                relation_data.append(relation)
+    return relation_data
+
+class UnregisteredHookError(Exception): pass
+
+class Hooks(object):
+    def __init__(self):
+        super(Hooks, self).__init__()
+        self._hooks = {}
+    def register(self, name, function):
+        self._hooks[name] = function
+    def execute(self, args):
+        hook_name = os.path.basename(args[0])
+        if hook_name in self._hooks:
+            self._hooks[hook_name]()
+        else:
+            raise UnregisteredHookError(hook_name)

=== added file 'scripts/charmsupport/nrpe.py'
--- scripts/charmsupport/nrpe.py	1970-01-01 00:00:00 +0000
+++ scripts/charmsupport/nrpe.py	2013-08-14 18:21:07 +0000
@@ -0,0 +1,169 @@
+"""Compatibility with the nrpe-external-master charm"""
+# source: 27:lp:charmsupport
+# Copyright 2012 Canonical Ltd.
+#
+# Authors:
+#  Matthew Wedgwood <[e-mail]>
+
+import subprocess
+import pwd
+import grp
+import os
+import re
+import shlex
+
+from hookenv import config, local_unit
+
+# This module adds compatibility with the nrpe_external_master
+# subordinate charm. To use it in your charm:
+# 
+# 1. Update metadata.yaml
+#
+#   provides:
+#     (...)
+#     nrpe-external-master:
+#       interface: nrpe-external-master
+#           scope: container
+# 
+# 2. Add the following to config.yaml
+#
+#    nagios_context:
+#      default: "juju"
+#      type: string
+#      description: |
+#        Used by the nrpe-external-master subordinate charm.
+#        A string that will be prepended to instance name to set the host name
+#        in nagios. So for instance the hostname would be something like:
+#            juju-myservice-0
+#        If you're running multiple environments with the same services in them
+#        this allows you to differentiate between them.
+#
+# 3. Add custom checks (Nagios plugins) to files/nrpe-external-master
+#
+# 4. Update your hooks.py with something like this:
+#
+#    import nrpe
+#    (...)
+#    def update_nrpe_config():
+#        nrpe_compat = NRPE("myservice")
+#        nrpe_compat.add_check(
+#            shortname = "myservice",
+#            description = "Check MyService",
+#            check_cmd = "check_http -w 2 -c 10 http://localhost"
+#            )
+#        nrpe_compat.add_check(
+#            "myservice_other",
+#            "Check for widget failures",
+#            check_cmd = "/srv/myapp/scripts/widget_check"
+#            )
+#        nrpe_compat.write()
+#
+#    def config_changed():
+#        (...)
+#        update_nrpe_config()
+#    def nrpe_external_master_relation_changed():
+#        update_nrpe_config()
+#
+# 5. ln -s hooks.py nrpe-external-master-relation-changed
+
+class CheckException(Exception): pass
+class Check(object):
+    shortname_re = '[A-Za-z0-9-_]*'
+    service_template = """
+#---------------------------------------------------
+# This file is Juju managed
+#---------------------------------------------------
+define service {{
+    use                             active-service
+    host_name                       {nagios_hostname}
+    service_description             {nagios_hostname}[{shortname}] {description}
+    check_command                   check_nrpe!check_{shortname}
+    servicegroups                   {nagios_servicegroup}
+}}
+"""
+    def __init__(self, shortname, description, check_cmd):
+        super(Check, self).__init__()
+        # XXX: could be better to calculate this from the service name
+        if not re.match(self.shortname_re, shortname):
+            raise CheckException("shortname must match {}".format(Check.shortname_re))
+        self.shortname = shortname
+        # Note: a set of invalid characters is defined by the Nagios server config
+        # The default is: illegal_object_name_chars=`~!$%^&*"|'<>?,()=
+        self.description = description
+        self.check_cmd = self._locate_cmd(check_cmd)
+
+    def _locate_cmd(self, check_cmd):
+        search_path = (
+            '/',
+            os.path.join(os.environ['CHARM_DIR'], 'files/nrpe-external-master'),
+            '/usr/lib/nagios/plugins',
+        )
+        command = shlex.split(check_cmd)
+        for path in search_path:
+            if os.path.exists(os.path.join(path,command[0])):
+                return os.path.join(path, command[0]) + " " + " ".join(command[1:])
+        subprocess.call(['juju-log', 'Check command not found: {}'.format(command[0])])
+        return ''
+
+    def write(self, nagios_context, hostname):
+        for f in os.listdir(NRPE.nagios_exportdir):
+            if re.search('.*check_{}.cfg'.format(self.shortname), f):
+                os.remove(os.path.join(NRPE.nagios_exportdir, f))
+
+        templ_vars = {
+            'nagios_hostname': hostname,
+            'nagios_servicegroup': nagios_context,
+            'description': self.description,
+            'shortname': self.shortname,
+        }
+        nrpe_service_text = Check.service_template.format(**templ_vars)
+        nrpe_service_file = '{}/service__{}_check_{}.cfg'.format(
+            NRPE.nagios_exportdir, hostname, self.shortname)
+        with open(nrpe_service_file, 'w') as nrpe_service_config:
+            nrpe_service_config.write(str(nrpe_service_text))
+
+        nrpe_check_file = '/etc/nagios/nrpe.d/check_{}.cfg'.format(self.shortname)
+        with open(nrpe_check_file, 'w') as nrpe_check_config:
+            nrpe_check_config.write("# check {}\n".format(self.shortname))
+            nrpe_check_config.write("command[check_{}]={}\n".format(
+                self.shortname, self.check_cmd))
+
+    def run(self):
+        subprocess.call(self.check_cmd)
+
+class NRPE(object):
+    nagios_logdir = '/var/log/nagios'
+    nagios_exportdir = '/var/lib/nagios/export'
+    nrpe_confdir = '/etc/nagios/nrpe.d'
+    def __init__(self):
+        super(NRPE, self).__init__()
+        self.config = config()
+        self.nagios_context = self.config['nagios_context']
+        self.unit_name = local_unit().replace('/', '-')
+        self.hostname = "{}-{}".format(self.nagios_context, self.unit_name)
+        self.checks = []
+
+    def add_check(self, *args, **kwargs):
+        self.checks.append( Check(*args, **kwargs) )
+
+    def write(self):
+        try:
+            nagios_uid = pwd.getpwnam('nagios').pw_uid
+            nagios_gid = grp.getgrnam('nagios').gr_gid
+        except:
+            subprocess.call(['juju-log', "Nagios user not set up, nrpe checks not updated"])
+            return
+
+        if not os.path.exists(NRPE.nagios_exportdir):
+            subprocess.call(['juju-log', 'Exiting as {} is not accessible'.format(NRPE.nagios_exportdir)])
+            return
+
+        if not os.path.exists(NRPE.nagios_logdir):
+            os.mkdir(NRPE.nagios_logdir)
+            os.chown(NRPE.nagios_logdir, nagios_uid, nagios_gid)
+
+        for nrpecheck in self.checks:
+            nrpecheck.write(self.nagios_context, self.hostname)
+
+        if os.path.isfile('/etc/init.d/nagios-nrpe-server'):
+            subprocess.call(['service', 'nagios-nrpe-server', 'reload'])

=== added file 'scripts/update-nrpe.py'
--- scripts/update-nrpe.py	1970-01-01 00:00:00 +0000
+++ scripts/update-nrpe.py	2013-08-14 18:21:07 +0000
@@ -0,0 +1,14 @@
+#!/usr/bin/env python
+from charmsupport import nrpe
+
+
+def update_nrpe_config():
+    nrpe_compat = nrpe.NRPE()
+    nrpe_compat.add_check(
+        'App is accessible', 'Check the app can be downloaded',
+        'check-app-access.sh')
+    nrpe_compat.write()
+
+
+if __name__ == '__main__':
+    update_nrpe_config()

=== modified file 'tests/20-functional.test'
--- tests/20-functional.test	2013-08-08 13:53:22 +0000
+++ tests/20-functional.test	2013-08-14 18:21:07 +0000
@@ -226,6 +226,17 @@
         self.handle_browser_warning()
         self.assertEnvironmentIsConnected()
 
+    def test_nrpe_check_available(self):
+        # Make sure the check-app-access.sh script's ADDRESS is available.
+        unit_info = self.juju_deploy(
+            self.charm, options={'juju-gui-source': JUJU_GUI_TEST_BRANCH})
+        hostname = unit_info['public-address']
+        conn = httplib.HTTPSConnection(hostname)
+        # This request matches the ADDRESS var in the script.
+        conn.request('GET', '/juju-ui/version.js')
+        message = 'ADDRESS in check-app-access.sh is not accessible.'
+        self.assertEqual(200, conn.getresponse().status, message)
+
 
 if __name__ == '__main__':
     unittest.main(verbosity=2)