Class: Kube::Cluster::Middleware::Stack

Inherits:
Object
  • Object
show all
Defined in:
lib/kube/cluster/middleware/stack.rb

Overview

An ordered pipeline of middleware that processes a manifest. Each middleware receives the manifest and mutates it in place.

stack = Kube::Cluster::Middleware::Stack.new do
  use Middleware::ServiceForDeployment
  use Middleware::Labels, app: "web"
  use Middleware::Namespace, "production"
end

stack.call(manifest)

Instance Method Summary collapse

Constructor Details

#initialize(&block) ⇒ Stack

Returns a new instance of Stack.



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# File 'lib/kube/cluster/middleware/stack.rb', line 18

def initialize(&block)
  @middleware = []
  instance_eval(&block) if block
end

Instance Method Details

#call(manifest) ⇒ Object

Run the manifest through every middleware in order. Each middleware mutates the manifest in place.



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# File 'lib/kube/cluster/middleware/stack.rb', line 30

def call(manifest)
  @middleware.each do |klass, args, kwargs|
    klass.new(*args, **kwargs).call(manifest)
  end
end

#empty? ⇒ Boolean

True when no middleware has been registered.

Returns:

  • (Boolean) 


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# File 'lib/kube/cluster/middleware/stack.rb', line 37

def empty?
  @middleware.empty?
end

#use(klass, *args, **kwargs) ⇒ Object

Register a middleware class with optional positional and keyword arguments.



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# File 'lib/kube/cluster/middleware/stack.rb', line 24

def use(klass, *args, **kwargs)
  @middleware << [klass, args, kwargs]
end