providers/docker: can set environmental variables

plugins/providers/docker/action/create.rb

@@ -46,6 +46,7 @@ module VagrantPlugins
 
           {
             cmd:        @provider_config.cmd,
+            env:        @provider_config.env,
             extra_args: @provider_config.create_args,
             hostname:   @machine_config.vm.hostname,
             image:      @provider_config.image,

plugins/providers/docker/config.rb

@@ -9,6 +9,11 @@ module VagrantPlugins
       # @return [Array<String>]
       attr_accessor :create_args
 
+      # Environmental variables to set in the container.
+      #
+      # @return [Hash]
+      attr_accessor :env
+
       # True if the Docker container exposes SSH access. If this is true,
       # then Vagrant can do a bunch more things like setting the hostname,
       # provisioning, etc.
@@ -45,6 +50,7 @@ module VagrantPlugins
       def initialize
         @cmd        = UNSET_VALUE
         @create_args = []
+        @env        = {}
         @has_ssh    = UNSET_VALUE
         @image      = UNSET_VALUE
         @ports      = []
@@ -55,9 +61,19 @@ module VagrantPlugins
         @vagrant_vagrantfile = UNSET_VALUE
       end
 
+      def merge(other)
+        super.tap do |result|
+          env = {}
+          env.merge!(@env) if @env
+          env.merge!(other.env) if other.env
+          result.env = env
+        end
+      end
+
       def finalize!
         @cmd        = [] if @cmd == UNSET_VALUE
         @create_args = [] if @create_args == UNSET_VALUE
+        @env       ||= {}
         @has_ssh    = false if @has_ssh == UNSET_VALUE
         @image      = nil if @image == UNSET_VALUE
         @privileged = false if @privileged == UNSET_VALUE

plugins/providers/docker/driver.rb

@@ -20,8 +20,10 @@ module VagrantPlugins
         volumes = Array(params[:volumes])
         name    = params.fetch(:name)
         cmd     = Array(params.fetch(:cmd))
+        env     = params.fetch(:env)
 
         run_cmd = %W(docker run --name #{name} -d)
+        run_cmd += env.map { |k,v| ['-e', "#{k}=#{v}"] }
         run_cmd += ports.map { |p| ['-p', p.to_s] }
         run_cmd += volumes.map { |v| ['-v', v.to_s] }
         run_cmd += %W(--privileged) if params[:privileged]

test/unit/plugins/providers/docker/config_spec.rb

@@ -25,6 +25,7 @@ describe VagrantPlugins::DockerProvider::Config do
     before { subject.finalize! }
 
     its(:cmd) { should eq([]) }
+    its(:env) { should eq({}) }
     its(:image) { should be_nil }
     its(:privileged) { should be_false }
     its(:vagrant_machine) { should be_nil }
@@ -40,4 +41,23 @@ describe VagrantPlugins::DockerProvider::Config do
     subject.finalize!
     assert_valid
   end
+
+  describe "#merge" do
+    context "env vars" do
+      let(:one) { described_class.new }
+      let(:two) { described_class.new }
+
+      subject { one.merge(two) }
+
+      it "should merge the values" do
+        one.env["foo"] = "bar"
+        two.env["bar"] = "baz"
+
+        expect(subject.env).to eq({
+          "foo" => "bar",
+          "bar" => "baz",
+        })
+      end
+    end
+  end
 end