Merge pull request sous-chefs#1044 from smcavallo/image_purge

Image prune

README.md

@@ -577,6 +577,44 @@ docker_image 'alpine' do
 end
 ```
 
+## docker_image_prune
+
+The `docker_image_prune` is responsible for pruning Docker images from the system. It speaks directly to the [Docker Engine API](https://docs.docker.com/engine/api/v1.35/#operation/ImagePrune).
+Note - this is best implemented by subscribing to `docker_image` changes.  There is no need to to clean up old images upon each converge.  It is best done at the end of a chef run (delayed) only if a new image was pulled.
+
+### Actions
+
+- `:prune` - Delete unused images
+
+### Properties
+
+The `docker_image_prune` resource properties map to filters
+
+- `dangling` - When set to true (or 1), prune only unused and untagged images. When set to false (or 0), all unused images are pruned
+- `prune_until` - Prune images created before this timestamp. The <timestamp> can be Unix timestamps, date formatted timestamps, or Go duration strings (e.g. 10m, 1h30m) computed relative to the daemon machine’s time.
+- `with_label/without_label` -  (label=<key>, label=<key>=<value>, label!=<key>, or label!=<key>=<value>) Prune images with (or without, in case label!=... is used) the specified labels.
+- `host` - A string containing the host the API should communicate with. Defaults to `ENV['DOCKER_HOST']` if set.
+
+### Examples
+
+- default action, default properties
+
+```ruby
+docker_image_prune 'prune-old-images'
+```
+
+- All filters
+
+```ruby
+docker_image_prune "prune-old-images" do
+  dangling true
+  prune_until '1h30m'
+  with_label 'com.example.vendor=ACME'
+  without_label 'no_prune'
+  action :prune
+end
+```
+
 ## docker_tag
 
 Docker tags work very much like hard links in a Unix filesystem. They are just references to an existing image. Therefore, the docker_tag resource has taken inspiration from the Chef `link` resource.

libraries/docker_image_prune.rb

@@ -0,0 +1,39 @@
+module DockerCookbook
+  class DockerImagePrune < DockerBase
+    resource_name :docker_image_prune
+    # Requires docker API v1.25
+    # Modify the default of read_timeout from 60 to 120
+    property :read_timeout, default: 120, desired_state: false
+    property :host, [String, nil], default: lazy { ENV['DOCKER_HOST'] }, desired_state: false
+
+    # https://docs.docker.com/engine/api/v1.35/#operation/ImagePrune
+    property :dangling, [TrueClass, FalseClass], default: true
+    property :prune_until, String
+    # https://docs.docker.com/engine/reference/builder/#label
+    property :with_label, String
+    property :without_label, String
+
+    #########
+    # Actions
+    #########
+
+    default_action :prune
+
+    action :prune do
+      # Have to call this method ourselves due to
+      # https://github.com/swipely/docker-api/pull/507
+      json = generate_json(new_resource)
+      # Post
+      res = connection.post('/images/prune', json)
+      Chef::Log.info res
+    end
+
+    def generate_json(new_resource)
+      opts = { filters: ["dangling=#{new_resource.dangling}"] }
+      opts[:filters].push("until=#{new_resource.prune_until}") if new_resource.property_is_set?(:prune_until)
+      opts[:filters].push("label=#{new_resource.with_label}") if new_resource.property_is_set?(:with_label)
+      opts[:filters].push("label!=#{new_resource.without_label}") if new_resource.property_is_set?(:without_label)
+      opts.to_json
+    end
+  end
+end

spec/docker_test/image_prune_spec.rb

@@ -0,0 +1,24 @@
+require 'spec_helper'
+
+describe 'docker_test::image_prune' do
+  context 'it steps over the provider' do
+    cached(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '18.04').converge(described_recipe) }
+
+    context 'testing default action, default properties' do
+      it 'prunes docker_image[hello-world]' do
+        expect(chef_run).to prune_docker_image_prune('hello-world').with(
+          dangling: true
+        )
+      end
+
+      it 'prunes docker_image[hello-world]' do
+        expect(chef_run).to prune_docker_image_prune('prune-old-images').with(
+          dangling: true,
+          prune_until: '1h30m',
+          with_label: 'com.example.vendor=ACME',
+          without_label: 'no_prune'
+        )
+      end
+    end
+  end
+end

spec/libraries/image_prune_spec.rb

@@ -0,0 +1,27 @@
+# Load all the libraries
+require 'chef'
+Dir['libraries/*.rb'].each { |f| require File.expand_path(f) }
+
+describe DockerCookbook::DockerImagePrune do
+  let(:resource) { DockerCookbook::DockerImagePrune.new('rspec') }
+
+  it 'has a default action of [:prune]' do
+    expect(resource.action).to eql([:prune])
+  end
+
+  it 'generates filter json' do
+    # Arrange
+    expected = '{"filters":["dangling=true","until=1h30m","label=com.example.vendor=ACME","label!=no_prune"]}'
+    resource.dangling = true
+    resource.prune_until = '1h30m'
+    resource.with_label = 'com.example.vendor=ACME'
+    resource.without_label = 'no_prune'
+    resource.action :prune
+
+    # Act
+    actual = resource.generate_json(resource)
+
+    # Assert
+    expect(actual).to eq(expected)
+  end
+end

test/cookbooks/docker_test/recipes/image_prune.rb

@@ -0,0 +1,15 @@
+#########################
+# :prune
+#########################
+
+docker_image_prune 'hello-world' do
+  dangling true
+end
+
+docker_image_prune "prune-old-images" do
+  dangling true
+  prune_until '1h30m'
+  with_label 'com.example.vendor=ACME'
+  without_label 'no_prune'
+  action :prune
+end