oops, link:
http://groups.google.com/group/ec2-on-rails-discuss
On 10/11/07, Paul M <[EMAIL PROTECTED]> wrote:
>
> there is an Ec2-rails group that is about to move in to their
> territory. They are ripe for a code swap.
>
> Paul
>
> On Sep 30, 10:57 am, Joe <[EMAIL PROTECTED]> wrote:
> > Hi all,
> >
> > I've been working on a plugin to manage deployments of clusters on EC2
> > through Capistrano. I'm looking to see if anyone is interested in
> > collaborating on it, or using it in alpha form to give me some
> > feedback. I'm not going to release it yet since it needs more
> > development and testing, but I would like to get some suggestions on
> > features to add.
> >
> > The tool is meant to manage the setup and confiiguration of machines
> > prior to running a normal cap:deploy of a specific application. It is
> > not meant to replace that.
> >
> > Here's an example of a cluster recipe (this is made up, so there may
> > be some logical errors in the setup, but it should illiustrate the
> > idea):
> >
> > -----
> >
> > cluster = elasticize.creater_cluster("mykey") do
> > on_create do |cluster|
> > app_group = create_group(cluster, :app) do
> > authorize_ingress :proto => :tcp, :ports => 22
> > authorize_ingress :proto => [ :tcp, :udp ], :ports => 5036
> > end
> > webserver_group = create_group(cluster, :webserver_group) do
> > authorize_ingress :proto => :tcp, :ports => [ 22, 80 ]
> > end
> >
> > app_group.authorize_ingress :from => :webserver_group
> > webserver_group.authorize_ingress :from => :app_group
> > end
> > end
> >
> > app = elasticize.create_image :app, 'ami-12345678',
> > cluster, :app_group
> > web = elasticize.create_image :web, 'ami-87654321',
> > cluster, :webserver_group do
> > on_create do
> > # Get security updates
> > run "aptitude update -y"
> > run "aptitude upgrade -y"
> > end
> > end
> >
> > elasticize.create_role :postfix, web do
> > on_create do |process|
> > modify "/etc/postfix/main.cf" do |r|
> > r.sub(/(^myhostname[^=]*=.*$)/, "myhostname =
> > #{process.instance.dns}")
> > end
> > end
> >
> > on_stop { run "/etc/init.d/postfix stop" }
> > on_start do |process|
> > run "/etc/init.d/postfix start"
> > process.notify! :app, :port => 1234
> > end
> > end
> >
> > elasticize.create_role :app, rails do
> > needs :db, :primary => true
> > needs :postfix
> >
> > on_receive do |process, source, event, *rest|
> > if event == :on_start
> > case source.role.name.to_sym
> > when :db
> > ip = process.instance.private_dns
> > port = *rest
> > when :postfix
> > # TODO: modify the rails configuration to point to the postfix
> > server
> > ip = process.instance.private_dns
> > port = *rest
> > end
> > end
> > end
> > end
> >
> > # Create an elastic role for the web server, bound to the 'rails' AMI
> > elasticize.create_role :web, rails do
> > needs :app
> >
> > on_receive do |process, source, event, *rest|
> > if event == :on_start
> > case source.role.name.to_sym
> > when :app
> > end
> > end
> > end
> >
> > on_create do
> > # Install needed gems
> > install_gem "daemons"
> > install_gem "gem_plugin"
> > install_gem "mongrel_cluster"
> > install_gem "mongrel", :version => '1.0.1'
> > end
> > end
> >
> > -----
> >
> > You can then create the cluster with a cap cluster:create. This will
> > create the keys, security groups, permissions and instances. When a
> > particular instance is created, its corresponding image's 'on_start'
> > callback is called. Additionally, the create task will bind all
> > 'elasitc' roles to a particular machine and create the appropriate
> > capistrano role internally. When the binding occurs, the corresponding
> > on_start callback are called for the process' corresponding role.
> > There are additional callbacks when instances are terminated or leave
> > the cluster.
> >
> > The 'needs' method indicates that a particular elastic role is
> > dependent upon another, and that its' processes will accept
> > notifications (in the on_receive handler) of specific events within
> > the cluster from prerequisite processes (where a process represents a
> > binding of a role to an EC2 instance, since a role can have multiple
> > processes). The notifications are specified via the notify! method in
> > a process' on_start callback, and allows that process to deliver
> > dynamic configuration data to its dependent roles' processes.
> >
> > The 'provides' method specifies the number of processes which will
> > exist for a given role. Also, 'create_role' can specify capistrano
> > subroles (limited to a hash of keys to boolean values for now) like
> > this:
> >
> > primary = elasticize.create_role :db, some_image, :primary => true do
> > # Default is one if unspecified
> > provides :exactly => 1
> > end
> >
> > secondary = elasticize.create_role, :db, some_image do
> > provides :min => 2, :max => 4
> > end
> >
> > A planned feature will allow you to add and remove processes
> > dynamically, bounded by the min / max number specified in the recipe.
> >
> > cap cluster:add ROLE=db
> >
> > This is not meant to be a thorough write up, just a taste if what is
> > available.
> >
> > If you think you may be able to help, or just have some ideas for what
> > you'd like to see, please get in touch. In particular, API feedback or
> > help writing tests would be greatly appreciated.
> >
> > Joe
>
>
> >
>
--~--~---------~--~----~------------~-------~--~----~
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at http://groups.google.com/group/capistrano
-~----------~----~----~----~------~----~------~--~---
