[Docker] add dockerEnvVars support

src/main/scala/com/typesafe/sbt/packager/docker/DockerPlugin.scala

@@ -61,7 +61,7 @@ object DockerPlugin extends AutoPlugin {
     */
   val UnixSeparatorChar = '/'
 
-  override def requires = UniversalPlugin
+  override def requires: Plugins = UniversalPlugin
 
   override def projectConfigurations: Seq[Configuration] = Seq(Docker)
 
@@ -71,6 +71,7 @@ object DockerPlugin extends AutoPlugin {
     dockerExposedUdpPorts := Seq(),
     dockerExposedVolumes := Seq(),
     dockerLabels := Map(),
+    dockerEnvVars := Map(),
     dockerRepository := None,
     dockerUsername := None,
     dockerAlias := DockerAlias(
@@ -104,6 +105,7 @@ object DockerPlugin extends AutoPlugin {
       generalCommands ++
         Seq(makeWorkdir(dockerBaseDirectory)) ++ makeAdd(dockerVersion.value, dockerBaseDirectory, user, group) ++
         dockerLabels.value.map(makeLabel) ++
+        dockerEnvVars.value.map(makeEnvVar) ++
         makeExposePorts(dockerExposedPorts.value, dockerExposedUdpPorts.value) ++
         makeVolumes(dockerExposedVolumes.value, user, group) ++
         Seq(makeUser(user), makeEntrypoint(dockerEntrypoint.value), makeCmd(dockerCmd.value))
@@ -175,6 +177,15 @@ object DockerPlugin extends AutoPlugin {
     Cmd("LABEL", variable + "=\"" + value.toString + "\"")
   }
 
+  /**
+    * @param envVar
+    * @return ENV command
+    */
+  private final def makeEnvVar(envVar: (String, String)): CmdLike = {
+    val (variable, value) = envVar
+    Cmd("ENV", variable + "=\"" + value.toString + "\"")
+  }
+
   /**
     * @param dockerBaseDirectory, the installation directory
     */

src/main/scala/com/typesafe/sbt/packager/docker/Keys.scala

@@ -33,6 +33,8 @@ trait DockerKeys {
   val dockerBuildOptions = SettingKey[Seq[String]]("dockerBuildOptions", "Options used for the Docker build")
   val dockerBuildCommand = SettingKey[Seq[String]]("dockerBuildCommand", "Command for building the Docker image")
   val dockerLabels = SettingKey[Map[String, String]]("dockerLabels", "Labels applied to the Docker image")
+  val dockerEnvVars =
+    SettingKey[Map[String, String]]("dockerEnvVars", "Environment Variables applied to the Docker image")
   val dockerRmiCommand =
     SettingKey[Seq[String]]("dockerRmiCommand", "Command for removing the Docker image from the local registry")
 

src/main/scala/com/typesafe/sbt/packager/docker/dockerfile.scala

@@ -36,7 +36,7 @@ trait CmdLike {
   * }}}
   */
 case class ExecCmd(cmd: String, args: String*) extends CmdLike {
-  def makeContent =
+  def makeContent: String =
     "%s [%s]\n" format (cmd, args.map('"' + _ + '"').mkString(", "))
 }
 
@@ -59,7 +59,7 @@ case class ExecCmd(cmd: String, args: String*) extends CmdLike {
   * }}}
   */
 case class Cmd(cmd: String, args: String*) extends CmdLike {
-  def makeContent = "%s %s\n" format (cmd, args.mkString(" "))
+  def makeContent: String = "%s %s\n" format (cmd, args.mkString(" "))
 }
 
 /**
@@ -76,7 +76,7 @@ case class Cmd(cmd: String, args: String*) extends CmdLike {
   * }}}
   */
 case class CombinedCmd(cmd: String, arg: CmdLike) extends CmdLike {
-  def makeContent = "%s %s\n" format (cmd, arg.makeContent)
+  def makeContent: String = "%s %s\n" format (cmd, arg.makeContent)
 }
 
 /** Represents dockerfile used by docker when constructing packages. */

src/sbt-test/docker/envVars/build.sbt

@@ -0,0 +1,19 @@
+enablePlugins(DockerPlugin)
+
+name := "simple-test"
+
+version := "0.1.0"
+
+dockerEnvVars := Map("FOO" -> "bar", "FOO_BAR" -> "foo bar", "NUMBER" -> "123")
+
+
+TaskKey[Unit]("checkDockerfile") := {
+  val dockerfile = IO.read((stagingDirectory in Docker).value / "Dockerfile")
+
+  assert(dockerfile contains """ENV FOO="bar"""", s"does not contain foo=bar\n$dockerfile")
+  assert(dockerfile contains """ENV FOO_BAR="foo bar"""", s"does not contain foo=bar\n$dockerfile")
+  assert(dockerfile contains """ENV NUMBER="123"""", s"does not contain foo=bar\n$dockerfile")
+
+  streams.value.log.success("Successfully tested Dockerfile")
+  ()
+}

src/sbt-test/docker/envVars/project/plugins.sbt

@@ -0,0 +1 @@
+addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % sys.props("project.version"))

src/sbt-test/docker/envVars/test

@@ -0,0 +1,3 @@
+# Stage the distribution and ensure files show up.
+> docker:stage
+> checkDockerfile

src/sphinx/formats/docker.rst

@@ -110,6 +110,9 @@ Environment Settings
   ``dockerLabels``
     A map of labels that will be applied to the Docker image.
 
+  ``dockerEnvVars``
+    A map of environment variables that will be applied to the Docker image.
+
   ``dockerEntrypoint``
     Overrides the default entrypoint for docker-specific service discovery tasks before running the application.
     Defaults to the bash executable script, available at ``bin/<script name>`` in the current ``WORKDIR`` of ``/opt/docker``.