providers/docker: pull setting, default false [hashicorpGH-5932]

CHANGELOG.md

@@ -8,7 +8,8 @@ BUG FIXES:
   - guests/ubuntu: setting hostname fixed in 12.04 [GH-5937]
   - hosts/linux: NFS can be configured without `$TMP` set on the host [GH-5954]
   - hosts/linux: NFS will sudo copying back to `/etc/exports` [GH-5957]
-  - providers/virtulabox: remove UNC path conversion on Windows since it
+  - providers/docker: Add `pull` setting, default to false [GH-5932]
+  - providers/virtualbox: remove UNC path conversion on Windows since it
       caused mounting regressions [GH-5933]
   - provisioners/puppet: Windows Puppet 4 paths work correctly [GH-5967]
   - provisioners/puppet: Fix config merging errors [GH-5958]

plugins/providers/docker/action/pull.rb

@@ -13,7 +13,7 @@ def call(env)
           @driver          = @machine.provider.driver
 
           # Skip pulling if the image is built
-          return @app.call(env) if @env[:create_image]
+          return @app.call(env) if @env[:create_image] || !@provider_config.pull
 
           image = @provider_config.image
           env[:ui].output(I18n.t("docker_provider.pull", image: image))

plugins/providers/docker/config.rb

@@ -61,6 +61,12 @@ class Config < Vagrant.plugin("2", :config)
       # @return [String]
       attr_accessor :name
 
+      # If true, the image will be pulled on every `up` and `reload`
+      # to ensure the latest image.
+      #
+      # @return [Bool]
+      attr_accessor :pull
+
       # True if the docker container is meant to stay in the "running"
       # state (is a long running process). By default this is true.
       #
@@ -140,6 +146,7 @@ def initialize
         @image      = UNSET_VALUE
         @name       = UNSET_VALUE
         @links      = []
+        @pull       = UNSET_VALUE
         @ports      = UNSET_VALUE
         @privileged = UNSET_VALUE
         @remains_running = UNSET_VALUE
@@ -199,6 +206,7 @@ def finalize!
         @has_ssh    = false if @has_ssh == UNSET_VALUE
         @image      = nil if @image == UNSET_VALUE
         @name       = nil if @name == UNSET_VALUE
+        @pull       = false if @pull == UNSET_VALUE
         @ports      = [] if @ports == UNSET_VALUE
         @privileged = false if @privileged == UNSET_VALUE
         @remains_running = true if @remains_running == UNSET_VALUE

website/docs/source/v2/docker/configuration.html.md

@@ -60,6 +60,9 @@ General settings:
     across all containers on the host VM. By default Vagrant will generate
     some random name.
 
+  * `pull` (bool) - If true, the image will be pulled on every `up` and
+    `reload`. Defaults to false.
+
   * `ports` (array of strings) - Ports to expose from the container to the
     host. These should be in the format of `host:container`.