Resolve Dependencies Once

[citruspi]

A common pattern in Tyr is inheriting from a parent Server type and then in the configure method:

• Calling super(Type).configure()
• Modifying the server's configuration (e.g. IAM policies, security groups, etc)
• Re-resolving these dependencies

However, this means that when provisioning e.g. a MongoDataNode you end up setting the Chef attributes 4 times, resolving the security groups twice, and resolving the IAM policies thrice. That's a lot of wasted time.

This moves

• resolution of IAM stuff
• resolution of security groups
• resolution of ingress groups to add
• setting of Chef attributes

to a method called resolve_dependencies which should be invoked once before invoking launch and after every invocation of configure has been completed.

I've made the necessary adjustments to autorun in Server and provision in the IIS and Nginx clusters to invoke it.

Essentially this significantly reduces the time spent between establish_logger and launch and removes a number of API requests for information that we already have.

[citruspi]

In addition, the resolve_dependencies method formats each IAM policy, security group, and ingress group to add. So instead of writing

self.ingress_groups_to_add.extend([		
    "{env}-web".format(env=env_prefix),		
    "{env}-nginx".format(env=env_prefix),		
    "{env}-queueproc-jobs".format(env=env_prefix)		
])

you can just write

self.ingress_groups_to_add.extend([		
    '{env}-web',
    '{env}-nginx',
    '{env}-queueproc-jobs'
])

The following variables are available during formatting:

Variable	Value	Example
environment	environment	prod
env	environment[0]	p
group	group	speedtest
type	server_type	mongo
envcl	{env}-{group}-{type}	p-speedtest-mongo

I've set the default security groups for each server to

['management', '{env}-{type}-management',  '{envcl}', 'chef-nodes']