Class: K8s::Stack

Inherits:
Object
  • Object
show all
Includes:
Logging
Defined in:
lib/k8s/stack.rb

Overview

Usage: customize the LABEL and CHECKSUM_ANNOTATION

Constant Summary collapse

LABEL =

Label used to identify resources belonging to this stack

'k8s.kontena.io/stack'
CHECKSUM_ANNOTATION =

Annotation used to identify resource versions

'k8s.kontena.io/stack-checksum'
LAST_CONFIG_ANNOTATION =

Annotation used to identify last applied configuration

'kubectl.kubernetes.io/last-applied-configuration'
PRUNE_IGNORE =

List of apiVersion:kind combinations to skip for stack prune These would lead to stack prune misbehaving if not skipped.

[
  'v1:ComponentStatus', # apiserver ignores GET /v1/componentstatuses?labelSelector=... and returns all resources
  'v1:Endpoints' # inherits stack label from service, but not checksum annotation
].freeze

Constants included from Logging

Logging::LOG_LEVEL, Logging::LOG_TARGET

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Logging

included, #logger, #logger!

Methods included from Logging::ModuleMethods

#debug!, #log_level, #log_level=, #quiet!, #verbose!

Constructor Details

#initialize(name, resources = [], debug: false, label: self.class::LABEL, checksum_annotation: self.class::CHECKSUM_ANNOTATION, last_configuration_annotation: self.class::LAST_CONFIG_ANNOTATION) ⇒ Stack 



61
62
63
64
65
66
67
68
69
70
 
# File 'lib/k8s/stack.rb', line 61

def initialize(name, resources = [], debug: false, label: self.class::LABEL, checksum_annotation: self.class::CHECKSUM_ANNOTATION, last_configuration_annotation: self.class::LAST_CONFIG_ANNOTATION)
  @name = name
  @resources = resources
  @keep_resources = {}
  @label = label
  @checksum_annotation = checksum_annotation
  @last_config_annotation = last_configuration_annotation

  logger! progname: name, debug: debug
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



53
54
55
 
# File 'lib/k8s/stack.rb', line 53

def name
  @name
end

#resources ⇒ Object (readonly)

Returns the value of attribute resources.



53
54
55
 
# File 'lib/k8s/stack.rb', line 53

def resources
  @resources
end

Class Method Details

.apply(name, path, client, prune: true, **options) ⇒ K8s::Stack 



41
42
43
 
# File 'lib/k8s/stack.rb', line 41

def self.apply(name, path, client, prune: true, **options)
  load(name, path, **options).apply(client, prune: prune)
end

.delete(name, client, **options) ⇒ Object

Remove any installed stack resources.



49
50
51
 
# File 'lib/k8s/stack.rb', line 49

def self.delete(name, client, **options)
  new(name, **options).delete(client)
end

.load(name, path, **options) ⇒ K8s::Stack 



30
31
32
33
 
# File 'lib/k8s/stack.rb', line 30

def self.load(name, path, **options)
  resources = K8s::Resource.from_files(path)
  new(name, resources, **options)
end

Instance Method Details

#apply(client, prune: true) ⇒ Array<K8s::Resource> 



97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
 
# File 'lib/k8s/stack.rb', line 97

def apply(client, prune: true)
  server_resources = client.get_resources(resources)

  resources.zip(server_resources).map do |resource, server_resource|
    if !server_resource
      logger.info "Create resource #{resource.apiVersion}:#{resource.kind}/#{resource.metadata.name} in namespace #{resource.metadata.namespace} with checksum=#{resource.checksum}"
      keep_resource! client.create_resource(prepare_resource(resource))
    elsif server_resource.metadata.annotations&.dig(@checksum_annotation) != resource.checksum
      logger.info "Update resource #{resource.apiVersion}:#{resource.kind}/#{resource.metadata.name} in namespace #{resource.metadata.namespace} with checksum=#{resource.checksum}"
      r = prepare_resource(resource)
      if server_resource.can_patch?(@last_config_annotation)
        keep_resource! client.patch_resource(server_resource, server_resource.merge_patch_ops(r.to_hash, @last_config_annotation))
      else
        # try to update with PUT
        keep_resource! client.update_resource(server_resource.merge(prepare_resource(resource)))
      end
    else
      logger.info "Keep resource #{server_resource.apiVersion}:#{server_resource.kind}/#{server_resource.metadata.name} in namespace #{server_resource.metadata.namespace} with checksum=#{server_resource.metadata.annotations[@checksum_annotation]}"
      keep_resource! server_resource
    end
  end

  prune(client, keep_resources: true) if prune
end

#delete(client) ⇒ Object

Delete all stack resources



182
183
184
 
# File 'lib/k8s/stack.rb', line 182

def delete(client)
  prune(client, keep_resources: false)
end

#keep_resource!(resource) ⇒ K8s::Resource

key MUST NOT include resource.apiVersion: the same kind can be aliased in different APIs



125
126
127
 
# File 'lib/k8s/stack.rb', line 125

def keep_resource!(resource)
  @keep_resources["#{resource.kind}:#{resource.metadata.name}@#{resource.metadata.namespace}"] = resource.metadata.annotations[@checksum_annotation]
end

#keep_resource?(resource) ⇒ Boolean 



131
132
133
134
135
136
 
# File 'lib/k8s/stack.rb', line 131

def keep_resource?(resource)
  keep_annotation = @keep_resources["#{resource.kind}:#{resource.metadata.name}@#{resource.metadata.namespace}"]
  return false unless keep_annotation

  keep_annotation == resource.metadata&.annotations.dig(@checksum_annotation)
end

#prepare_resource(resource, base_resource: nil) ⇒ K8s::Resource

rubocop:disable Lint/UnusedMethodArgument



76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
 
# File 'lib/k8s/stack.rb', line 76

def prepare_resource(resource, base_resource: nil)
  # TODO: base_resource is not used anymore, kept for backwards compatibility for a while

  # calculate checksum  only from the "local" source
  checksum = resource.checksum

  # add stack metadata
  resource.merge(
    metadata: {
      labels: { @label => name },
      annotations: {
        @checksum_annotation => checksum,
        @last_config_annotation => Util.recursive_compact(resource.to_h).to_json
      }
    }
  )
end

#prune(client, keep_resources:, skip_forbidden: true) ⇒ Object

Delete all stack resources that were not applied



142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
 
# File 'lib/k8s/stack.rb', line 142

def prune(client, keep_resources:, skip_forbidden: true)
  # using skip_forbidden: assume we can't create resource types that we are forbidden to list, so we don't need to prune them either
  client.list_resources(labelSelector: { @label => name }, skip_forbidden: skip_forbidden).sort do |a, b|
    # Sort resources so that namespaced objects are deleted first
    if a.metadata.namespace == b.metadata.namespace
      0
    elsif a.metadata.namespace.nil? && !b.metadata.namespace.nil?
      1
    else
      -1
    end
  end.each do |resource|
    next if PRUNE_IGNORE.include? "#{resource.apiVersion}:#{resource.kind}"

    resource_label = resource.metadata.labels ? resource.metadata.labels[@label] : nil
    resource_checksum = resource.metadata.annotations ? resource.metadata.annotations[@checksum_annotation] : nil

    logger.debug { "List resource #{resource.apiVersion}:#{resource.kind}/#{resource.metadata.name} in namespace #{resource.metadata.namespace} with checksum=#{resource_checksum}" }

    if resource_label != name
      # apiserver did not respect labelSelector
    elsif resource.metadata&.ownerReferences && !resource.metadata.ownerReferences.empty?
      logger.info "Server resource #{resource.apiVersion}:#{resource.apiKind}/#{resource.metadata.name} in namespace #{resource.metadata.namespace} has ownerReferences and will be kept"
    elsif keep_resources && keep_resource?(resource)
      # resource is up-to-date
    else
      logger.info "Delete resource #{resource.apiVersion}:#{resource.kind}/#{resource.metadata.name} in namespace #{resource.metadata.namespace}"
      begin
        client.delete_resource(resource, propagationPolicy: 'Background')
      rescue K8s::Error::NotFound => e
        # assume aliased objects in multiple API groups, like for Deployments
        # alternatively, a custom resource whose definition was already deleted earlier
        logger.debug { "Ignoring #{e} : #{e.message}" }
      end
    end
  end
end