Merge pull request #17 from seglo/master

Support docker-compose variable substitution

README.md

@@ -67,6 +67,7 @@ plugin will attempt to locate it in one of three places with the precedence orde
     testTagsToExecute =: // Set of ScalaTest Tags to execute when dockerComposeTest is run. Separate multiple tags by a comma. It defaults to executing all tests.
     testDependenciesClasspath =: // The path to all managed and unmanaged Test and Compile dependencies. This path needs to include the ScalaTest Jar for the tests to execute. This defaults to all managedClasspath and unmanagedClasspath in the Test and fullClasspath in the Compile Scope.
     testCasesJar =: // The path to the Jar file containing the tests to execute. This defaults to the Jar file with the tests from the current sbt project.
+    variablesForSubstitution =: // A Map[String,String] of variables to substitute in your docker-compose file.  These are substituted substituted by the plugin and not using environment variables.
 
 There are several sample projects showing how to configure sbt-docker-compose that can be found in the [**examples**] (examples) folder.
 
@@ -274,6 +275,24 @@ launch a running instance that consists of both images:
 Note how the docker-compose.yml file for the root project tags each image with "\<localBuild\>". This allows dockerComposeUp 
 to know that these images should not be updated from the Docker Registry.
 
+5) [**basic-variable-substitution**] (examples/basic-variable-substitution): This project demonstrates how you can re-use your 
+existing docker-compose.yml with [variable substitution](https://docs.docker.com/compose/compose-file/#variable-substitution) 
+using sbt-docker-compose.  Instead of passing your variables as environment variables you can define them in your build.sbt 
+programmatically.
+
+build.sbt:
+
+    variablesForSubstitution := Map("SOURCE_PORT" -> "5555")
+
+docker-compose.yml:
+
+    basic:
+      image: basic:1.0.0
+      environment:
+        JAVA_TOOL_OPTIONS: -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005
+      ports:
+        - "${SOURCE_PORT}:5005"
+
 Currently Unsupported Docker Compose Fields
 -------------------------------------------
 1) "build:" - All docker compose services need to specify an "image:" field.

examples/basic-variable-substitution/build.sbt

@@ -0,0 +1,11 @@
+name := "basic"
+
+version := "1.0.0"
+
+scalaVersion := "2.10.6"
+
+enablePlugins(JavaAppPackaging, DockerComposePlugin)
+
+dockerImageCreationTask := (publishLocal in Docker).value
+
+variablesForSubstitution := Map("SOURCE_PORT" -> "5555")

examples/basic-variable-substitution/docker/docker-compose.yml

@@ -0,0 +1,6 @@
+basic:
+  image: basic:1.0.0
+  environment:
+    JAVA_TOOL_OPTIONS: -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005
+  ports:
+    - "${SOURCE_PORT}:5005"

examples/basic-variable-substitution/project/build.properties

@@ -0,0 +1 @@
+sbt.version=0.13.11

examples/basic-variable-substitution/project/plugins.sbt

@@ -0,0 +1,3 @@
+addSbtPlugin("com.typesafe.sbt" %% "sbt-native-packager" % "1.1.0")
+
+addSbtPlugin("com.tapad" % "sbt-docker-compose" % "1.0.8")

examples/basic-variable-substitution/src/main/scala/BasicApp.scala

@@ -0,0 +1,14 @@
+import scala.Console._
+import scala.concurrent.duration._
+
+object BasicApp extends App {
+  println("Application started....")
+
+  val deadline = 1.hour.fromNow
+  do {
+    println(s"Running application. Seconds left until showdown: ${deadline.timeLeft.toSeconds}")
+    Thread.sleep(1000)
+  } while (deadline.hasTimeLeft())
+
+  println("Application shutting down....")
+}

src/main/scala/com/tapad/docker/ComposeFile.scala

@@ -227,15 +227,25 @@ trait ComposeFile extends SettingsHelper with ComposeCustomTagHelpers with Print
     }
   }
 
-  def readComposeFile(composePath: String): yamlData = {
-    val fileReader = fromFile(composePath).reader()
-    try {
-      new Yaml().load(fileReader).asInstanceOf[java.util.Map[String, java.util.LinkedHashMap[String, Any]]].asScala.toMap
-    } finally {
-      fileReader.close()
-    }
+  def readComposeFile(composePath: String, variables: Vector[(String, String)] = Vector.empty): yamlData = {
+    val yamlString = fromFile(composePath).getLines().mkString("\n")
+    val yamlUpdated = processVariableSubstitution(yamlString, variables)
+
+    new Yaml().load(yamlUpdated).asInstanceOf[java.util.Map[String, java.util.LinkedHashMap[String, Any]]].asScala.toMap
   }
 
+  /**
+   * Substitute all docker-compose variables in the YAML file.  This is traditionally done by docker-compose itself,
+   * but is being performed by the plugin to support other functionality.
+   * @param yamlString Stringified docker-compose file.
+   * @param variables Substitution variables.
+   * @return An updated stringified docker-compile file.
+   */
+  def processVariableSubstitution(yamlString: String, variables: Vector[(String, String)]) =
+    variables.foldLeft(yamlString) {
+      case (y, (key, value)) => y.replaceAll("\\$\\{" + key + "\\}", value)
+    }
+
   def deleteComposeFile(composePath: String): Boolean = {
     Try(new File(composePath).delete()) match {
       case Success(i) => true

src/main/scala/com/tapad/docker/DockerComposeKeys.scala

@@ -18,4 +18,5 @@ trait DockerComposeKeysLocal {
   val testCasesJar = settingKey[String]("The path to the Jar file containing the tests to execute. This defaults to the Jar file with the tests from the current sbt project.")
   val testDependenciesClasspath = taskKey[String]("The path to all managed and unmanaged Test and Compile dependencies. This path needs to include the ScalaTest Jar for the tests to execute. This defaults to all managedClasspath and unmanagedClasspath in the Test and fullClasspath in the Compile Scope.")
   val runningInstances = AttributeKey[List[RunningInstanceInfo]]("For Internal Use: Contains information on the set of running Docker Compose instances.")
+  val variablesForSubstitution = settingKey[Map[String, String]]("Specify a Map of String to String that will be passed as environment variables to docker-compose and can be used for variable substitution.")
 }

src/main/scala/com/tapad/docker/DockerComposePlugin.scala

@@ -72,6 +72,7 @@ object DockerComposePlugin extends DockerComposePluginLocal {
     val testTagsToExecute = DockerComposeKeys.testTagsToExecute
     val testCasesJar = DockerComposeKeys.testCasesJar
     val scalaTestJar = DockerComposeKeys.testDependenciesClasspath
+    val variablesForSubstitution = DockerComposeKeys.variablesForSubstitution
   }
 }
 
@@ -166,11 +167,12 @@ class DockerComposePluginLocal extends AutoPlugin with ComposeFile with DockerCo
    */
   def startDockerCompose(implicit state: State, args: Seq[String]): (State, String) = {
     val composeFilePath = getSetting(composeFile)
+    val variables = getSetting(variablesForSubstitution).toVector
 
     printBold(s"Creating Local Docker Compose Environment.")
     printBold(s"Reading Compose File: $composeFilePath")
 
-    val composeYaml = readComposeFile(composeFilePath)
+    val composeYaml = readComposeFile(composeFilePath, variables)
     val servicesInfo = processCustomTags(state, args, composeYaml)
     val updatedComposePath = saveComposeFile(composeYaml)
     println(s"Created Compose File with Processed Custom Tags: $updatedComposePath")

src/main/scala/com/tapad/docker/DockerComposeSettings.scala

@@ -40,6 +40,7 @@ trait DockerComposeSettingsLocal extends PrintFormatting {
       (fullClasspathCompile.files ++ classpathTestManaged.files ++ classpathTestUnmanaged.files).map(_.getAbsoluteFile).mkString(":")
     },
     testCasesJar := artifactPath.in(Test, packageBin).value.getAbsolutePath,
+    variablesForSubstitution := Map[String, String](),
     commands ++= Seq(dockerComposeUpCommand, dockerComposeStopCommand, dockerComposeInstancesCommand, dockerComposeTest)
   )
 }

src/test/resources/variable_substitution.yml

@@ -0,0 +1,4 @@
+testservice:
+  image: testservice:0.0.1
+  ports:
+    - "${SOURCE_PORT}:5005"

src/test/scala/ComposeFileProcessingSpec.scala

@@ -244,6 +244,17 @@ class ComposeFileProcessingSpec extends FunSuite with BeforeAndAfter with OneIns
     }
   }
 
+  test("Validate that docker-compose variables are substituted") {
+    val composeMock = getComposeFileMock()
+    val composeFilePath = getClass.getResource("variable_substitution.yml").getPath
+    doReturn(composeFilePath).when(composeMock).getSetting(composeFile)(null)
+
+    val composeYaml = composeMock.readComposeFile(composeFilePath, Vector(("SOURCE_PORT", "5555")))
+
+    val ports = composeYaml.get("testservice").get.get("ports").asInstanceOf[util.ArrayList[String]].get(0)
+    assert(ports == "5555:5005")
+  }
+
   def getComposeFileMock(serviceName: String = "testservice", versionNumber: String = "1.0.0", noBuild: Boolean = false): ComposeFile = {
     val composeMock = spy(new DockerComposePluginLocal)