Introduce support for reference repository paths ending with /${GIT_URL} to replace by url => funny dir subtree in filesystem

Author: jimklimov

src/main/java/org/jenkinsci/plugins/gitclient/CliGitAPIImpl.java

@@ -762,6 +762,39 @@ public void execute() throws GitException, InterruptedException {
 
                 if (reference != null && !reference.isEmpty()) {
                     File referencePath = new File(reference);
+                    if (!referencePath.exists()) {
+                        if (reference.endsWith("/${GIT_URL}")) {
+                            // See also JGitAPIImpl.java and keep the two blocks in
+                            // sync (TODO: refactor into a method both would use?)
+                            // For mass-configured jobs, like Organization Folders,
+                            // allow to support parameterized paths to many refrepos.
+                            // End-users can set up webs of symlinks to same repos
+                            // known by different URLs (and/or including their forks
+                            // also cached in same index). Luckily all URL chars are
+                            // valid parts of path name... in Unix... Maybe parse or
+                            // escape chars for URLs=>paths with Windows in mind?
+                            // https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions
+                            // Further ideas: beside "GIT_URL" other meta variables
+                            // can be introduced, e.g. to escape non-ascii chars for
+                            // portability? Support SHA or MD5 hashes of URLs as
+                            // pathnames?
+                            reference = reference.replaceAll("\\$\\{GIT_URL\\}$", url).replaceAll("/*$", "").replaceAll(".git$", "");
+                            referencePath = new File(reference);
+                            if (!referencePath.exists()) {
+                                // Normalize the URLs with or without .git suffix to
+                                // be served by same dir with the refrepo contents
+                                reference += ".git";
+                                referencePath = new File(reference);
+                            }
+                            // Note: both these logs are needed, they are used in selftest
+                            if (referencePath.exists()) {
+                                listener.getLogger().println("[WARNING] Parameterized reference path replaced with: " + reference);
+                            } else {
+                                listener.getLogger().println("[WARNING] Parameterized reference path replaced with: " + reference + " was not found");
+                            }
+                        }
+                    }
+
                     if (!referencePath.exists())
                         listener.getLogger().println("[WARNING] Reference path does not exist: " + reference);
                     else if (!referencePath.isDirectory())

src/main/java/org/jenkinsci/plugins/gitclient/JGitAPIImpl.java

@@ -1434,6 +1434,27 @@ public void execute() throws GitException, InterruptedException {
                     // the repository builder does not create the alternates file
                     if (reference != null && !reference.isEmpty()) {
                         File referencePath = new File(reference);
+                        if (!referencePath.exists()) {
+                            if (reference.endsWith("/${GIT_URL}")) {
+                                // See comments in CliGitAPIImpl.java for details
+                                // Keep the two blocks in sync (refactor into method?)
+                                reference = reference.replaceAll("\\$\\{GIT_URL\\}$", url).replaceAll("/*$", "").replaceAll(".git$", "");
+                                referencePath = new File(reference);
+                                if (!referencePath.exists()) {
+                                    // Normalize the URLs with or without .git suffix to
+                                    // be served by same dir with the refrepo contents
+                                    reference += ".git";
+                                    referencePath = new File(reference);
+                                }
+                                // Note: both these logs are needed, they are used in selftest
+                                if (referencePath.exists()) {
+                                    listener.getLogger().println("[WARNING] Parameterized reference path replaced with: " + reference);
+                                } else {
+                                    listener.getLogger().println("[WARNING] Parameterized reference path replaced with: " + reference + " was not found");
+                                }
+                            }
+                        }
+
                         if (!referencePath.exists())
                             listener.getLogger().println("[WARNING] Reference path does not exist: " + reference);
                         else if (!referencePath.isDirectory())

src/test/java/org/jenkinsci/plugins/gitclient/GitClientCloneTest.java

@@ -238,6 +238,21 @@ public void test_clone_reference() throws Exception, IOException, InterruptedExc
         assertThat("Reference repo logged in: " + messages, handler.containsMessageSubstring("Using reference repository: "), is(true));
     }
 
+    @Test
+    public void test_clone_reference_parameterized() throws Exception, IOException, InterruptedException {
+        testGitClient.clone_().url(workspace.localMirror()).repositoryName("origin").reference(workspace.localMirror() + "/${GIT_URL}").execute();
+        testGitClient.checkout().ref("origin/master").branch("master").execute();
+        check_remote_url(workspace, testGitClient, "origin");
+        // Verify JENKINS-46737 expected log message is written
+        String messages = StringUtils.join(handler.getMessages(), ";");
+        assertThat("Reference repo name-parsing logged in: " + messages, handler.containsMessageSubstring("Parameterized reference path replaced with: "), is(true));
+        // Skip: Missing if clone failed - currently would, with bogus path above and not pre-created path structure
+        //assertThat("Reference repo logged in: " + messages, handler.containsMessageSubstring("Using reference repository: "), is(true));
+        //assertAlternateFilePointsToLocalMirror();
+        //assertBranchesExist(testGitClient.getBranches(), "master");
+        //assertNoObjectsInRepository();
+    }
+
     private static final String SRC_DIR = (new File(".")).getAbsolutePath();
 
     @Test