can puppet help you run docker on a t2.micro?
TRANSCRIPT
Can Puppet help you run Docker on a T2.micro?
Presented by: Neil Millardwww.mitese.co.uk
whoami
• Always programming
• IT professional since 1995
• Devops / Infrastructure as Code
• Helicopter pilot
Encryptinator!
• Uses https://github.com/TomPoulton/hiera-eyaml Ruby gem
• Containerised Sinatra app
agenda
• Masterless puppet
• Hieradata
• Roles and Profiles
• Modules
• Ordering
• AWS EC2
• Stages
• Docker
Why Masterless puppet
• Pets VS
• Scale UP
Cattle
Scale OUT
http://www.slideshare.net/gmccance/cern-data-centre-evolution - attrib Bill Baker/Microsoft
https://www.iha.com
Why Masterless puppet
• Puppet Masters
• Pets
• Maintenance
• Care
• Sometimes fragile
Why Masterless puppet
• Rebuild rather than reconfigure
• Temporary
• Build Server
-> work/develop
-> destroy server
Masterless puppet
• Bootstrapping
• Cloud-init
• userdata- Environment- Role
Masterless puppet
• Bake or not to bake?
• Preparing to run puppetTru-strap https://github.com/MSMFG/tru-strapArgs: Provisioning or configuration repository
Role + Environment Facts, for hiera lookup
• Install puppet
Masterless puppet
• Fetch configuration (infrastructure as code)
• Puppet• hieradata
• Puppetfiles
• manifests
• modules• profiles
• roles
• https://github.com/neilmillard/puppet-dockerhost
agenda
• Masterless puppet
• Hieradata
• Roles and Profiles
• Modules (via Puppetfiles)
• Ordering
• AWS EC2
• Stages
• Docker
hieradata
• Separation of data from codedocker::run { $container:
image => $image,
command => $command,
memory_limit => $memory_limit,
cpuset => $cpuset,
ports => $ports,
expose => $expose,
volumes => $volumes,
links => $links,
use_name => $use_name,
running => $running,
volumes_from => $volumes_from,
net => $net,
username => $username,
hostname => $hostname,
env => $env,
dns => $dns,
dns_search => $dns_search,
lxc_conf => $lxc_conf,
restart_service => $restart_service,
disable_network => $disable_network,
privileged => $privileged,
detach => $detach,
extra_parameters => $extra_parameters,
pull_on_start => $pull_on_start,
depends => $depends,
tty => $tty,
require => $requires,
}
eyamld:
image: "nginx"
ports:
- "80:80"
env:
- NGINX_HOST=foobar.com
- NGINX_PORT=80
use_name: true
docker::run { ‘eyamld’:
image => "nginx",
command => undef,
memory_limit => 0b,
cpuset => [],
ports => ["80:80“],
expose => [],
volumes => [],
links => [],
use_name => true,
running => true,
volumes_from => [],
net => 'bridge',
username => false,
hostname => false,
env => [NGINX_HOST=foobar.com,
NGINX_PORT=80
],
dns => [],
dns_search => [],
lxc_conf => [],
restart_service => true,
disable_network => false,
privileged => false,
detach => true,
extra_parameters => undef,
pull_on_start => false,
depends => [],
tty => false,
require => [],
}
+ =
hieradata
• Separation of data from code
• Automatic parameter lookup# In this example, $parameter's value gets set # when `myclass` is eventually declared.# Class definition:class myclass ($parameter_one = "default text") {
file {'/tmp/foo':ensure => file,content => $parameter_one,
}}
hieradata
• Separation of data from code
• Automatic parameter lookup
• Code reuse with lookups
profile::docker_containers::containers:
eyamld:
image: "nginx"
ports:
- "80:80"
env:
- NGINX_HOST=foobar.com
- NGINX_PORT=80
use_name: true
# profile::docker_containers
class profile::docker_containers
($containers={}) {
create_resources (
'profile::docker_container', $containers )
}
hieradata
• Hiera.yaml – configuration
---
:backends:
- eyaml
- yaml
:eyaml:
:datadir: /etc/puppetlabs/puppet/hieradata
:pkcs7_private_key: /etc/puppet/secure/keys/private_key.pkcs7.pem
:pkcs7_public_key: /etc/puppet/secure/keys/public_key.pkcs7.pem
:yaml:
:datadir: /etc/puppetlabs/puppet/hieradata
:hierarchy:
- "%{::init_env}/%{::init_role}"
- "%{::init_role}"
- "%{::init_env}"
- common
Roles and Profiles• Business Layer (Roles)
only includes profilesno logicone server, one role
• Implementation Layer (Profiles)Includes classesModules and Resourcescreate_resources{}
Craig Dunn - http://www.slideshare.net/PuppetLabs/roles-talkPuppet - https://docs.puppet.com/pe/2016.2/r_n_p_intro.html
http://www.slideshare.net/DaeHyung/learning-puppet-basic-thing #64
Roles and Profiles
• Defined as classes within either Roles Module or Profiles Module
• Roles contain Profiles
• Use include, require or class
class role::dockerhost {
include ::profile::base
include ::profile::os_limits
include ::profile::docker_base
include ::profile::docker_containers
class { '::profile::swapfile':
before => Class['profile::base']
}
}
# profile::docker_containers
class profile::docker_containers
($containers={}) {
create_resources (
'profile::docker_container', $containers )
}
Modules
• Puppetforge or Git (Github)
Modules
• Librarian or r10k from Puppetfile
forge "https://forgeapi.puppetlabs.com"
# Base modules
mod "saz/timezone", "3.0.1"
mod "saz/rsyslog", "4.0.2"
agenda
• Masterless puppet
• Hieradata
• Roles and Profiles
• Modules
• Ordering
• AWS EC2
• Stages
• Docker
ordering
• Puppet execution is in parallel
• Dependencies need order
anchor { 'ntp::begin': } ->
class { '::ntp::install': } ->
class { '::ntp::config': } ~>
class { '::ntp::service': } ->
anchor { 'ntp::end': }
ordering
• Require and beforeclass { ‘install-ssl':
installdir => "$installdir",
require => Exec['unarchive-source'],
before => File['copy-init-file'],
}
ordering
• ->
• Everything else is attempted at the same time
->
class { ‘install-ssl':
installdir => "$installdir",
}
->
The Puppet Run
• Puppet catalog compilation
• Puppet catalog apply
http://www.slideshare.net/bernstein_aaron/puppet-introduction-26593192 #25
Data
Hieradata
agenda
• Masterless puppet
• Hieradata
• Roles and Profiles
• Modules
• Ordering
• AWS EC2
• Stages
• Docker
AWS EC2
• Flexible workloads
• Is limiting on memory
• May need a swapfile
Model vCPU (burst) Mem (GiB)
t2.nano 1 0.5
t2.micro 1 1
t2.small 1 2
t2.medium 2 4
t2.large 2 8
Stages
• Simple manifests best
• swapfile stage
stage { 'swapfile':
before => Stage['main'],
}
class { '::profile::swapfile':
stage => swapfile
before => Class['profile::base']
}
Stages
• Catalog compiles
• Runs each stage based on order
Notice: Compiled catalog for ip-10-96-4-130.internal in environment production in 2.10
Notice: /Stage[swapfile]/Profile::Swapfile/Exec[Create swap file /mnt/swap.1]/returns:
Notice: /Stage[swapfile]/Profile::Swapfile/File[/mnt/swap.1]/mode: mode changed '0644'
...
Notice: /Stage[main]/Profile::Docker_base/Exec[yum install -y docker-io]/returns:
Notice: /Stage[main]/Docker::Service/File[/etc/sysconfig/docker]/content: content
Stages
• Ordering across stages WILL break
• WARNING – use with care. Can cause dependency cycles
agenda
• Masterless puppet
• Hieradata
• Roles and Profiles
• Modules
• Ordering
• AWS EC2
• Stages
• Docker
Docker
• Containershttps://docs.docker.com/engine/understanding-docker/
Docker
• WhaleSay$ docker run docker/whalesay cowsay boo Unable to find image 'docker/whalesay:latest' locally latest: Pulling from docker/whalesaye9e06b06e14c: Pull completea82efea989f9: Pull complete37bea4ee0c81: Pull complete...99da72cfe067: Pull complete5d5bd9951e26: Pull completefb434121fc77: Already exists Digest: sha256:d6ee73f978a366cf97974115abe9c4099ed59c6f75c23d03c64446bb9cd49163 Status: Downloaded newer image for docker/whalesay:latest_____ < boo >-----\
Docker
• Dockerhost configurationdocker run --name eweb -p 80:80 –e “NGINX_HOST=foobar.com” –e “NGINX_PORT=80” –d nginx
• Docker compose
profile::docker_containers::containers:
eweb:
image: "nginx"
ports:
- "80:80"
env:
- NGINX_HOST=foobar.com
- NGINX_PORT=80
use_name: true
# profile::docker_containers
class profile::docker_containers
($containers={}) {
create_resources (
'profile::docker_container', $containers )
}
Docker
• Volumes
• Network
• Resource Constraints
• Ref: https://docs.docker.com/engine/reference/run/
Docker
• Production?
• Serverless
• Jenkins builds
• Scale
Docker
• Swarm
https://docs.docker.com/engine/swarm/swarm-tutorial/
https://github.com/jimfdavies/vagrant-docker-swarm
• Amazon EC2 Container Servicecontainer management that supports Docker containers
Can Puppet help you run Docker on a T2.micro?
• Boot, prep and build instance
• Puppet builds catalog and apply configuration from your heiradata
• Fetch images and run dockercontainers
