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Add the loadbalancer resource.

Some initial simplifications:
- only one Listener
- static (only use Instances)
- only http (no tcp or ssl)

Ref #164
Change-Id: Iaac06eff83a5c43049adc95a98ebe632e17b490c
Signed-off-by: Angus Salkeld <asalkeld@redhat.com>
changes/80/280/1
Angus Salkeld 10 years ago
parent
commit
894272f214
  1. 295
      heat/engine/loadbalancer.py
  2. 2
      heat/engine/resource_types.py
  3. 66
      templates/WordPress_With_LB.template

295
heat/engine/loadbalancer.py

@ -0,0 +1,295 @@
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# 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 urllib2
import json
import logging
from heat.common import exception
from heat.engine.resources import Resource
from heat.db import api as db_api
from heat.engine import parser
from novaclient.exceptions import NotFound
logger = logging.getLogger(__file__)
lb_template = '''
{
"AWSTemplateFormatVersion": "2010-09-09",
"Description": "Built in HAProxy server",
"Parameters" : {
"KeyName" : {
"Type" : "String"
}
},
"Resources": {
"LoadBalancerInstance": {
"Type": "AWS::EC2::Instance",
"Metadata": {
"AWS::CloudFormation::Init": {
"config": {
"packages": {
"yum": {
"haproxy" : []
}
},
"services": {
"systemd": {
"haproxy" : { "enabled": "true", "ensureRunning": "true" }
}
},
"files": {
"/etc/haproxy/haproxy.cfg": {
"content": ""},
"mode": "000644",
"owner": "root",
"group": "root"
}
}
}
},
"Properties": {
"ImageId": "F16-x86_64-cfntools",
"InstanceType": "m1.small",
"KeyName": { "Ref": "KeyName" },
"UserData": { "Fn::Base64": { "Fn::Join": ["", [
"#!/bin/bash -v\\n",
"/opt/aws/bin/cfn-init -s ",
{ "Ref": "AWS::StackName" },
" --region ", { "Ref": "AWS::Region" }, "\\n"
]]}}
}
}
},
"Outputs": {
"PublicIp": {
"Value": { "Fn::GetAtt": [ "LoadBalancerInstance", "PublicIp" ] },
"Description": "instance IP"
}
}
}
'''
#
# TODO(asalkeld) once we have done a couple of these composite
# Resources we should probably make a generic CompositeResource class.
# There will be plenty of scope for it. I resisted doing this initially
# to see how what the other composites require.
#
# Also the above inline template _could_ be placed in an external file
# at the moment this is because we will probably need to implement a
# LoadBalancer based on keepalived as well (for for ssl support).
#
class LoadBalancer(Resource):
listeners_schema = {
'InstancePort': {'Type': 'Integer',
'Required': True},
'LoadBalancerPort': {'Type': 'Integer',
'Required': True},
'Protocol': {'Type': 'String',
'Required': True,
'AllowedValues': ['TCP', 'HTTP']},
'SSLCertificateId': {'Type': 'String',
'Implemented': False},
'PolicyNames': {'Type': 'Map',
'Implemented': False}
}
healthcheck_schema = {
'HealthyThreshold': {'Type': 'Integer',
'Required': True},
'Interval': {'Type': 'Integer',
'Required': True},
'Target': {'Type': 'String',
'Required': True},
'Timeout': {'Type': 'Integer',
'Required': True},
'UnHealthyTheshold': {'Type': 'Integer',
'Required': True},
}
properties_schema = {
'AvailabilityZones': {'Type': 'List',
'Required': True},
'HealthCheck': {'Type': 'Map',
'Implemented': False,
'Schema': healthcheck_schema},
'Instances': {'Type': 'List'},
'Listeners': {'Type': 'List',
'Schema': listeners_schema},
'AppCookieStickinessPolicy': {'Type': 'String',
'Implemented': False},
'LBCookieStickinessPolicy': {'Type': 'String',
'Implemented': False},
'SecurityGroups': {'Type': 'String',
'Implemented': False},
'Subnets': {'Type': 'List',
'Implemented': False}
}
def __init__(self, name, json_snippet, stack):
Resource.__init__(self, name, json_snippet, stack)
self._nested = None
def _params(self):
# total hack - probably need an admin key here.
params = {'KeyName': {'Ref': 'KeyName'}}
p = self.stack.resolve_static_data(params)
return p
def nested(self):
if self._nested is None:
if self.instance_id is None:
return None
st = db_api.stack_get(self.stack.context, self.instance_id)
if not st:
raise exception.NotFound('Nested stack not found in DB')
n = parser.Stack(self.stack.context, st.name,
st.raw_template.parsed_template.template,
self.instance_id, self._params())
self._nested = n
return self._nested
def _instance_to_ipaddress(self, inst):
'''
Return the server's IP address, fetching it from Nova
'''
try:
server = self.nova().servers.get(inst)
except NotFound as ex:
logger.warn('Instance IP address not found (%s)' % str(ex))
else:
for n in server.networks:
return server.networks[n][0]
return '0.0.0.0'
def _haproxy_config(self, templ):
# initial simplifications:
# - only one Listener
# - static (only use Instances)
# - only http (no tcp or ssl)
#
# option httpchk HEAD /check.txt HTTP/1.0
gl = '''
global
daemon
maxconn 256
defaults
mode http
timeout connect 5000ms
timeout client 50000ms
timeout server 50000ms
'''
listener = self.properties['Listeners'][0]
lb_port = listener['LoadBalancerPort']
inst_port = listener['InstancePort']
spaces = ' '
frontend = '''
frontend http
bind *:%s
''' % (lb_port)
backend = '''
default_backend servers
backend servers
balance roundrobin
option http-server-close
option forwardfor
'''
servers = []
n = 1
for i in self.properties['Instances']:
ip = self._instance_to_ipaddress(i)
servers.append('%sserver server%d %s:%s' % (spaces, n,
ip, inst_port))
n = n + 1
return '%s%s%s%s\n' % (gl, frontend, backend, '\n'.join(servers))
def handle_create(self):
templ = json.loads(lb_template)
md = templ['Resources']['LoadBalancerInstance']['Metadata']
files = md['AWS::CloudFormation::Init']['config']['files']
cfg = self._haproxy_config(templ)
files['/etc/haproxy/haproxy.cfg']['content'] = cfg
self._nested = parser.Stack(self.stack.context,
self.name,
templ,
parms=self._params(),
metadata_server=self.stack.metadata_server)
rt = {'template': templ, 'stack_name': self.name}
new_rt = db_api.raw_template_create(None, rt)
parent_stack = db_api.stack_get(self.stack.context, self.stack.id)
s = {'name': self.name,
'owner_id': self.stack.id,
'raw_template_id': new_rt.id,
'user_creds_id': parent_stack.user_creds_id,
'username': self.stack.context.username}
new_s = db_api.stack_create(None, s)
self._nested.id = new_s.id
pt = {'template': self._nested.t, 'raw_template_id': new_rt.id}
new_pt = db_api.parsed_template_create(None, pt)
self._nested.parsed_template_id = new_pt.id
self._nested.create()
self.instance_id_set(self._nested.id)
def handle_delete(self):
try:
stack = self.nested()
except exception.NotFound:
logger.info("Stack not found to delete")
else:
if stack is not None:
stack.delete()
def FnGetAtt(self, key):
'''
We don't really support any of these yet.
'''
allow = ('CanonicalHostedZoneName',
'CanonicalHostedZoneNameID',
'DNSName',
'SourceSecurityGroupName',
'SourceSecurityGroupOwnerAlias')
if not key in allow:
raise exception.InvalidTemplateAttribute(resource=self.name,
key=key)
stack = self.nested()
if stack is None:
# This seems like a hack, to get past validation
return ''
if key == 'DNSName':
return stack.output('PublicIp')
else:
return ''

2
heat/engine/resource_types.py

@ -23,6 +23,7 @@ from heat.engine import resources
from heat.engine import cloud_watch
from heat.engine import eip
from heat.engine import instance
from heat.engine import loadbalancer
from heat.engine import security_group
from heat.engine import stack
from heat.engine import user
@ -42,6 +43,7 @@ _resource_classes = {
'AWS::EC2::SecurityGroup': security_group.SecurityGroup,
'AWS::EC2::Volume': volume.Volume,
'AWS::EC2::VolumeAttachment': volume.VolumeAttachment,
'AWS::ElasticLoadBalancing::LoadBalancer': loadbalancer.LoadBalancer,
'AWS::IAM::User': user.User,
'AWS::IAM::AccessKey': user.AccessKey,
'HEAT::HA::Restarter': instance.Restarter,

66
templates/WordPress_With_LB.template

@ -109,39 +109,59 @@
},
"WikiServerOne": {
"Type": "AWS::CloudFormation::Stack",
"DependsOn": "DatabaseServer",
"Properties": {
"TemplateURL": "https://raw.github.com/heat-api/heat/master/templates/WordPress_And_Http.template",
"Parameters": {
"KeyName" : { "Ref": "KeyName" },
"InstanceType" : { "Ref": "InstanceType" },
"DBName" : { "Ref": "DBName" },
"DBUsername" : { "Ref": "DBUsername" },
"DBPassword" : { "Ref": "DBPassword" },
"DBIpaddress" : { "Fn::GetAtt": [ "DatabaseServer", "Outputs.PublicIp" ]},
"LinuxDistribution": { "Ref": "LinuxDistribution" }
"Type": "AWS::EC2::Instance",
"DependsOn" : "DatabaseServer",
"Metadata": {
"AWS::CloudFormation::Init": {
"config": {
"packages": {
"yum": {
"httpd" : [],
"wordpress" : []
}
},
"services": {
"systemd": {
"httpd" : { "enabled": "true", "ensureRunning": "true" }
}
}
}
}
},
"Properties": {
"ImageId": { "Fn::FindInMap": [ "DistroArch2AMI", { "Ref": "LinuxDistribution" },
{ "Fn::FindInMap": [ "AWSInstanceType2Arch", { "Ref": "InstanceType" }, "Arch" ] } ] },
"InstanceType" : { "Ref": "InstanceType" },
"KeyName" : { "Ref": "KeyName" },
"UserData" : { "Fn::Base64": { "Fn::Join": ["", [
"#!/bin/bash -v\n",
"/opt/aws/bin/cfn-init\n",
"sed --in-place --e s/database_name_here/", { "Ref": "DBName" },
"/ --e s/username_here/", { "Ref": "DBUsername" },
"/ --e s/password_here/", { "Ref": "DBPassword" },
"/ --e s/localhost/", { "Fn::GetAtt": [ "DatabaseServer", "Outputs.PublicIp" ]},
"/ /usr/share/wordpress/wp-config.php\n"
]]}}
}
},
"LoadBalancer": {
"Type": "AWS::CloudFormation::Stack",
"DependsOn": "WikiServerOne",
"Properties": {
"TemplateURL": "https://raw.github.com/heat-api/heat/master/templates/HAProxy_Single_Instance.template",
"Parameters": {
"KeyName" : { "Ref": "KeyName" },
"InstanceType" : { "Ref": "InstanceType" },
"Server1" : { "Fn::Join": ["", [{ "Fn::GetAtt": [ "WikiServerOne", "Outputs.PublicIp" ]}, ":80"]] }
}
"LoadBalancer" : {
"Type" : "AWS::ElasticLoadBalancing::LoadBalancer",
"Properties" : {
"AvailabilityZones" : { "Fn::GetAZs" : "" },
"Instances" : [{"Ref": "WikiServerOne"}],
"Listeners" : [ {
"LoadBalancerPort" : "80",
"InstancePort" : "80",
"Protocol" : "HTTP"
}]
}
}
},
"Outputs": {
"WebsiteURL": {
"Value": { "Fn::Join": ["", ["http://", { "Fn::GetAtt": [ "LoadBalancer", "Outputs.PublicIp" ]}, "/wordpress"]] },
"Value": { "Fn::Join": ["", ["http://", { "Fn::GetAtt": [ "LoadBalancer", "DNSName" ]}, "/wordpress"]] },
"Description": "URL for Wordpress wiki"
}
}

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