Containers  and  Heat  and  Health  Maintenance  

Mike  Spreitzer  IBM  Research  

The  Take-­‐Away  •  You  can  use  Docker  through  Nova  •  Heat  provides  desired-­‐state  based  management  

•  OpenStack  can  do  health  maintenance  today  

Docker  and  Nova  •  There  is  a  “Docker  driver”  for  Nova  •  Allows  you  to  create/manage  Docker  containers  through  the  normal  API  for  VMs  

•  Special  images  

Heat  •  A  “template”  is  a  model:  desired  state  – Has  inputs  (“parameters”)  and  outputs  – Has  resources  

•  Most  correspond  to  an  object  in  an  OpenStack  API  •  Some  are  synthePc  things  

–  E.g.,  autoscaling  group  •  Each  has  inputs  (“properPes”)  and  outputs  (“aTributes”)  

•  A  “stack”  is  an  instance  of  a  template  –  Yes,  recursion  allowed  

•  Heat  allows  CRUD  of  stacks  from  templates  

The  Picture  of  Health  

OS::Neutron::LoadBalancer  

OS::Neutron::Pool  

OS::Nova::Server  

OS::Heat::HARestarter  

OS::Neutron::PoolMember  

OS::Ceilometer::Alarm  OS::Neutron::HealthMonitor  

Template  for  a  Container  with  Health  Maintenance,  p1  

heat_template_version: 2013-05-23!description: A container subject to health maintenance!parameters:! image:! type: string! description: Image used for containers! flavor:! type: string! description: flavor used by the containers! default: m1.tiny!

Template  for  a  Container  with  Health  Maintenance,  p2  

private_network:! type: string! description:! Name or ID of the network to which! the container will be attached! protocol_port:! type: number! description: port number where container listens! default: 80! pool_id:! type: string! description: LB Pool of which to be a member!

Template  for  a  Container  with  Health  Maintenance,  p3  

resources:! server:! type: OS::Nova::Server! properties:! flavor: {get_param: flavor}! image: {get_param: image}! networks:! - {network: {get_param: private_network}}! ! restarter:! type: OS::Heat::HARestarter! properties:! InstanceId: {get_resource: server}!

Template  for  a  Container  with  Health  Maintenance,  p4  

member:! type: OS::Neutron::PoolMember! properties:! pool_id: {get_param: pool_id}! address: {get_attr: [server, first_address]}! protocol_port: {get_param: protocol_port}!

Template  for  a  Container  with  Health  Maintenance,  p5  (old  version)  

gone_alarm:! type: OS::Ceilometer::Alarm! properties:! description: Detect container being unresponsive! meter_name: network.services.lb.member! statistic: avg! period: 70! evaluation_periods: 2! threshold: 1! alarm_actions: [ {get_attr:! [restarter, AlarmUrl]} ]! matching_metadata: {resource:! {get_resource: member} }! comparison_operator: lt!

Template  for  a  Container  with  Health  Maintenance,  p5  (new  version)  

gone_alarm:! type: OS::Ceilometer::Alarm! properties:! description: Detect container being unresponsive! meter_name: network.services.lb.member! statistic: avg! period: 70! evaluation_periods: 2! threshold: 1! alarm_actions: [ {get_attr:! [restarter, AlarmUrl]} ]! query: {field: resource_id, op: eq,! value: {get_resource: member} }! comparison_operator: lt!

Template  for  a  Container  with  Health  Maintenance,  p6  

outputs:! ceilometer_query:! value:! str_replace:! template:! ceilometer statistics! -m network.services.lb.member! -q resource_id=memberid -p 70 -a avg! params:! memberid: {get_resource: member}! description:! This is a Ceilometer CLI command that produces! stats similar to those used by the alarm!

Template  for  a  Container  with  Health  Maintenance,  p7  

restart_url:! value: {get_attr: [restarter, AlarmUrl]}! description: the webhook for the HARestarter! !

Also  Talk  to  Me  About  •  PaaS  and  IaaS  for  Containers  •  Balancing  an  ASG  across  AZs  •  HolisPc  placement  in  OpenStack