detect installation root dir via marker file (#1404)

* use current working dir for workspace

some users may want to install joern/ocular system-wide in a read-only
directory, and have their workspace e.g. in their user home
re https://discord.com/channels/832209896089976854/832214243230744626/887106423341875200

* make console/basedir configurable, mostly for tests

* detect installation root dir via marker file

#1387
introduced the assumption that the root directory is always two levels
up from the lib dir. That's not true for ocular, and a little brittle anyway.
This PR changes the behaviour to instead search for a marker file.

* adjust test

Author: mpollmeier

.installation_root

@@ -28,4 +28,7 @@ object ProjectRoot {
     else ???
   }
 
+  def find: File =
+    File(findRelativePath)
+
 }

codepropertygraph/src/main/scala/io/shiftleft/utils/ProjectRoot.scala

@@ -10,15 +10,28 @@ import scala.collection.mutable
   * @param environment A map of system environment variables.
   * */
 class InstallConfig(environment: Map[String, String] = sys.env) {
-  var rootPath: File = {
+  lazy val rootPath: File = {
     if (environment.contains("SHIFTLEFT_OCULAR_INSTALL_DIR")) {
       environment("SHIFTLEFT_OCULAR_INSTALL_DIR").toFile
     } else {
       val uriToLibDir = classOf[io.shiftleft.console.InstallConfig].getProtectionDomain.getCodeSource.getLocation.toURI
-      val pathToLibDir = new java.io.File(uriToLibDir).toPath
-      pathToLibDir.getParent.getParent.toFile.toScala
+      val pathToLibDir = File(uriToLibDir)
+      findRootDirectory(pathToLibDir).getOrElse(throw new AssertionError(s"""unable to find root installation directory
+           | context: tried to find marker file `$rootDirectoryMarkerFilename`
+           | started search in $pathToLibDir and searched $maxSearchDepth directories upwards""".stripMargin))
     }
   }
+
+  private val rootDirectoryMarkerFilename = ".installation_root"
+  private val maxSearchDepth = 10
+  private def findRootDirectory(currentSearchDir: File, currentSearchDepth: Int = 0): Option[File] = {
+    if (currentSearchDir.list.map(_.name).contains(rootDirectoryMarkerFilename))
+      Some(currentSearchDir)
+    else if (currentSearchDepth < maxSearchDepth && currentSearchDir.parentOption.isDefined)
+      findRootDirectory(currentSearchDir.parent)
+    else
+      None
+  }
 }
 
 object InstallConfig {

console/src/main/scala/io/shiftleft/console/ConsoleConfig.scala

@@ -1,16 +1,15 @@
 package io.shiftleft.console
 
-import better.files.{File, FileExtensions}
+import better.files.File
+import io.shiftleft.utils.ProjectRoot
 import org.scalatest.matchers.should.Matchers
 import org.scalatest.wordspec.AnyWordSpec
 
 class ConsoleConfigTest extends AnyWordSpec with Matchers {
   "An InstallConfig" should {
-    "set the rootPath to parent of directory containing jar by default" in {
+    "set the rootPath to directory containing `.installation_root` by default" in {
       val config = new InstallConfig(environment = Map.empty)
-      val uriToLibDir = classOf[io.shiftleft.console.InstallConfig].getProtectionDomain.getCodeSource.getLocation.toURI
-      val pathToLibDir = new java.io.File(uriToLibDir).toPath
-      config.rootPath shouldBe pathToLibDir.getParent.getParent.toFile.toScala
+      config.rootPath shouldBe ProjectRoot.find
     }
 
     "set the rootPath to SHIFTLEFT_OCULAR_INSTALL_DIR if it is defined" in {