Class: Kube::Schema::Manifest

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/kube/schema/manifest.rb

Overview

A flat, ordered collection of Kubernetes resources.

Manifest is Enumerable over Resource objects. It cannot be nested —appending one Manifest into another extracts and flattens its resources.

manifest = Kube::Schema::Manifest.new
manifest << deployment_resource
manifest << another_manifest   # flattened automatically
puts manifest.to_yaml          # multi-document YAML output

File I/O:

manifest = Kube::Schema::Manifest.open("cluster.yaml")
manifest << new_resource
manifest.write

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*resources, filename: nil) ⇒ Manifest

Create a new Manifest, optionally seeded with resources.

Parameters:

  • resources (Array<Resource, Manifest>) —

    initial resources to include

  • filename (String, nil) (defaults to: nil) —

    optional filename for file-backed manifests



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# File 'lib/kube/schema/manifest.rb', line 31

def initialize(*resources, filename: nil)
  @resources = []
  @filename  = filename

  resources.each { |r| self << r }
end

Instance Attribute Details

#filename ⇒ Object (readonly)

Returns the value of attribute filename.



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# File 'lib/kube/schema/manifest.rb', line 25

def filename
  @filename
end

Class Method Details

.open(path) ⇒ Manifest

Read a YAML file containing one or more Kubernetes resource documents and return a Manifest populated with Resource objects.

manifest = Kube::Schema::Manifest.open("deploy.yaml")
manifest.count  #=> 3
manifest.filename #=> "deploy.yaml"

Parameters:

  • path (String) —

    path to a YAML file

Returns:



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# File 'lib/kube/schema/manifest.rb', line 102

def self.open(path)
  contents = File.read(path)
  docs = if YAML.respond_to?(:safe_load_stream)
           YAML.safe_load_stream(contents, permitted_classes: [Symbol])
         else
           # Ruby < 3.1 fallback
           YAML.load_stream(contents)
         end

  resources = docs.compact.map { |doc| Resource.new(doc) }
  new(*resources, filename: path)
end

Instance Method Details

#<<(item) ⇒ self

Append a resource, manifest, or array of resources.

  • Resource objects are appended directly.

  • Manifest objects are flattened — their resources are extracted.

  • Arrays are iterated and each element is appended.

Parameters:

Returns:

  • (self) 


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# File 'lib/kube/schema/manifest.rb', line 46

def <<(item)
  case item
  when Manifest
    item.each { |r| @resources << r }
  when Array
    item.each { |r| self << r }
  when Resource
    @resources << item
  else
    raise ArgumentError,
      "Expected a Kube::Schema::Resource or Manifest, got #{item.class}. " \
      "Use Kube::Schema.parse(hash) once it is implemented to convert hashes."
  end

  self
end

#each {|Resource| ... } ⇒ Object

Yields:

  • (Resource) —

    each resource in insertion order



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# File 'lib/kube/schema/manifest.rb', line 64

def each(&block)
  @resources.each(&block)
end

#size ⇒ Object Also known as: length

Number of resources in the manifest.



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# File 'lib/kube/schema/manifest.rb', line 69

def size
  @resources.size
end

#to_a ⇒ Array<Hash>

Returns an array of resource hashes.

Returns:

  • (Array<Hash>) 


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# File 'lib/kube/schema/manifest.rb', line 85

def to_a
  @resources.dup
end

#to_yaml ⇒ String

Returns the manifest as multi-document YAML, separated by “—”. This is the standard format for Kubernetes manifest files.

Returns:

  • (String) 


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# File 'lib/kube/schema/manifest.rb', line 78

def to_yaml
  @resources.map { |r| r.to_yaml }.join("")
end

#write(path = nil) ⇒ String

Write the manifest to a file as multi-document YAML.

Parameters:

  • path (String, nil) (defaults to: nil) —

    destination path; defaults to the filename the manifest was opened from.

Returns:

  • (String) —

    the path written to

Raises:

  • (ArgumentError) —

    if no path is given and no filename is set



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# File 'lib/kube/schema/manifest.rb', line 121

def write(path = nil)
  path ||= @filename
  raise ArgumentError, "No filename set. Pass a path to #write or use Manifest.open." if path.nil?

  File.write(path, to_yaml)
  @filename = path
  path
end