Separate GUI into its own jar and add a servlet to serve the jar's content

Author: hlxid

.gitignore

@@ -37,6 +37,3 @@ project/plugins/project/
 
 # Plugin Data
 data/
-
-# Built gui
-/src/main/resources/chatoverflow-gui

build.sbt

@@ -99,6 +99,13 @@ bs := BootstrapUtility.bootstrapGenTask(streams.value.log, s"$scalaMajorVersion$
 deploy := BootstrapUtility.prepareDeploymentTask(streams.value.log, scalaMajorVersion)
 gui := BuildUtility(streams.value.log).guiTask(guiProjectPath.value, streams.value.cacheDirectory / "gui")
 
+Compile / packageBin := {
+  BuildUtility(streams.value.log).packageGUITask(guiProjectPath.value, scalaMajorVersion, crossTarget.value)
+  (Compile / packageBin).value
+}
+
+Compile / unmanagedJars := (crossTarget.value ** "chatoverflow-gui*.jar").classpath
+
 // ---------------------------------------------------------------------------------------------------------------------
 // UTIL
 // ---------------------------------------------------------------------------------------------------------------------
@@ -117,4 +124,3 @@ lazy val getDependencyList = Def.task[List[ModuleID]] {
 
 // Clears the built GUI dirs on clean
 cleanFiles += baseDirectory.value / guiProjectPath.value / "dist"
-cleanFiles += baseDirectory.value / "src" / "main" / "resources" / "chatoverflow-gui"

project/BootstrapUtility.scala

@@ -165,19 +165,15 @@ object BootstrapUtility {
   }
 
   /**
-    * Copies ONE jar file from the source to all target directories. Useful for single packaged jar files.
-    */
+   * Copies all jar files from the source to all target directories.
+   */
   private def copyJars(sourceDirectory: String, targetDirectories: List[String], logger: ManagedLogger): Unit = {
     val candidates = new File(sourceDirectory)
       .listFiles().filter(f => f.isFile && f.getName.toLowerCase.endsWith(".jar"))
-    if (candidates.length != 1) {
-      logger warn s"Unable to identify jar file in $sourceDirectory"
-    } else {
-      for (targetDirectory <- targetDirectories) {
-        Files.copy(Paths.get(candidates.head.getAbsolutePath),
-          Paths.get(s"$targetDirectory/${candidates.head.getName}"))
-        logger info s"Finished copying file '${candidates.head.getAbsolutePath}' to '$targetDirectory'."
-      }
+    for (targetDirectory <- targetDirectories; file <- candidates) {
+      Files.copy(Paths.get(file.getAbsolutePath),
+        Paths.get(s"$targetDirectory/${file.getName}"))
+      logger info s"Finished copying file '${file.getAbsolutePath}' to '$targetDirectory'."
     }
   }
 }

project/BuildUtility.scala

@@ -1,9 +1,13 @@
 import java.io.{File, IOException}
 import java.nio.file.{Files, StandardCopyOption}
+import java.util.jar.Manifest
 
+import com.fasterxml.jackson.databind.ObjectMapper
 import sbt.internal.util.ManagedLogger
 import sbt.util.{FileFunction, FilesInfo}
 
+import scala.io.Source
+
 /**
   * A build utility instance handles build tasks and prints debug information using the managed logger.
   *
@@ -151,15 +155,10 @@ class BuildUtility(logger: ManagedLogger) {
       val srcFiles = recursiveFileListing(new File(guiDir, "src"))
       val outDir = new File(guiDir, "dist")
 
-      if(!executeNpmCommand(guiDir, cacheDir, srcFiles + packageJson, "run build",
+      executeNpmCommand(guiDir, cacheDir, srcFiles + packageJson, "run build",
         () => logger error "GUI couldn't be built, please check above log for further details.",
         () => outDir
-      )) {
-        return // again early return on failure
-      }
-
-      // copy built gui into resources, will be included in the classpath on execution of the framework
-      sbt.IO.copyDirectory(outDir, new File("src/main/resources/chatoverflow-gui"))
+      )
     }
   }
 
@@ -212,6 +211,30 @@ class BuildUtility(logger: ManagedLogger) {
     }
   }
 
+  def packageGUITask(guiProjectPath: String, scalaMajorVersion: String, crossTargetDir: File): Unit = {
+    val dir = new File(guiProjectPath, "dist")
+    if (!dir.exists()) {
+      return
+    }
+
+    val files = recursiveFileListing(dir)
+
+    // contains tuples with the actual file as the first value and the name with directory in the jar as the second value
+    val jarEntries = files.map(file => (file, "/chatoverflow-gui/" + dir.toURI.relativize(file.toURI)))
+
+    val guiVersion = getGUIVersion(guiProjectPath)
+
+    sbt.IO.jar(jarEntries, new File(crossTargetDir, s"chatoverflow-gui_$scalaMajorVersion-$guiVersion.jar"), new Manifest())
+  }
+
+  private def getGUIVersion(guiProjectPath: String): String = {
+    val packageJson = Source.fromFile(s"$guiProjectPath/package.json")
+    val version = new ObjectMapper().reader().readTree(packageJson.mkString).get("version").asText()
+
+    packageJson.close()
+    version
+  }
+
   /**
     * Creates a file listing with all files including files in any sub-dir.
     *

project/plugins.sbt

@@ -1 +1,4 @@
-addSbtPlugin("net.virtual-void" % "sbt-dependency-graph" % "0.9.2")
+addSbtPlugin("net.virtual-void" % "sbt-dependency-graph" % "0.9.2")
+
+// JSON Lib (Jackson)
+libraryDependencies += "org.json4s" %% "json4s-jackson" % "3.5.2"

src/main/scala/ScalatraBootstrap.scala

@@ -4,7 +4,7 @@ import org.codeoverflow.chatoverflow.ui.web.rest.connector.ConnectorController
 import org.codeoverflow.chatoverflow.ui.web.rest.events.{EventsController, EventsDispatcher}
 import org.codeoverflow.chatoverflow.ui.web.rest.plugin.PluginInstanceController
 import org.codeoverflow.chatoverflow.ui.web.rest.types.TypeController
-import org.codeoverflow.chatoverflow.ui.web.{CodeOverflowSwagger, OpenAPIServlet}
+import org.codeoverflow.chatoverflow.ui.web.{CodeOverflowSwagger, GUIServlet, OpenAPIServlet}
 import org.scalatra._
 
 /**
@@ -30,5 +30,7 @@ class ScalatraBootstrap extends LifeCycle {
     context.mount(new PluginInstanceController(), "/instances/*", "instances")
     context.mount(new ConnectorController(), "/connectors/*", "connectors")
     context.mount(new OpenAPIServlet(), "/api-docs")
+
+    context.mount(new GUIServlet(), "/*")
   }
 }

src/main/scala/org/codeoverflow/chatoverflow/ui/web/GUIServlet.scala

@@ -0,0 +1,62 @@
+package org.codeoverflow.chatoverflow.ui.web
+
+import java.io.File
+import java.net.URI
+import java.util.jar.JarFile
+
+import org.codeoverflow.chatoverflow.WithLogger
+import org.eclipse.jetty.http.MimeTypes
+import org.eclipse.jetty.util.Loader
+import org.scalatra.{ActionResult, ScalatraServlet}
+
+import scala.io.Source
+
+/**
+ * A servlet to serve the GUI files of the chatoverflow-gui dir from the classpath.
+ * This directory is provided if the gui jar is added on the classpath.
+ * Responds with an error if the gui jar isn't on the classpath.
+ */
+class GUIServlet extends ScalatraServlet with WithLogger {
+
+  private val jarFilePath = {
+    val res = Loader.getResource(s"/chatoverflow-gui/")
+
+    // directory couldn't be found
+    if (res == null) {
+      logger error "GUI couldn't be found on the classpath! Has the GUI been built?"
+      null
+    } else {
+      // remove the path inside the jar and only keep the file path to the jar file
+      val jarPath = res.getFile.split("!").head
+      logger info s"GUI jar file found at ${new File(".").toURI.relativize(new URI(jarPath))}"
+
+      Some(jarPath)
+    }
+  }
+
+  get("/*") {
+    if (jarFilePath.isEmpty) {
+      ActionResult(500, "GUI couldn't be found on the classpath! Has the GUI been built?", Map())
+    } else {
+      val jarFile = new JarFile(new File(new URI(jarFilePath.get)))
+
+      val path = if (requestPath == "/")
+        "/index.html"
+      else
+        requestPath
+
+      val entry = jarFile.getEntry(s"/chatoverflow-gui$path")
+
+      val res = if (entry == null) {
+        ActionResult(404, s"Requested file '$path' couldn't be found in the GUI jar!", Map())
+      } else {
+        contentType = MimeTypes.getDefaultMimeByExtension(entry.getName)
+        Source.fromInputStream(jarFile.getInputStream(entry)).mkString
+      }
+
+      response.setHeader("Cache-Control", "no-cache,no-store")
+      jarFile.close()
+      res
+    }
+  }
+}

src/main/scala/org/codeoverflow/chatoverflow/ui/web/Server.scala

@@ -1,7 +1,6 @@
 package org.codeoverflow.chatoverflow.ui.web
 
 import org.codeoverflow.chatoverflow.{ChatOverflow, WithLogger}
-import org.eclipse.jetty.util.resource.Resource
 import org.eclipse.jetty.webapp.WebAppContext
 import org.scalatra.servlet.ScalatraListener
 
@@ -16,9 +15,8 @@ class Server(val chatOverflow: ChatOverflow, val port: Int) extends WithLogger {
   private val server = new org.eclipse.jetty.server.Server(port)
   private val context = new WebAppContext()
   context.setInitParameter("org.eclipse.jetty.servlet.Default.dirAllowed", "false")
-  context.setInitParameter("org.eclipse.jetty.servlet.Default.cacheControl", "no-cache,no-store")
   context setContextPath "/"
-  context.setBaseResource(Resource.newClassPathResource("/chatoverflow-gui/"))
+  context setResourceBase "/"
   context.addEventListener(new ScalatraListener)
 
   server.setHandler(context)