Support local-to-remote mirroring (#717)

Motivation
We currently support only remote-to-local mirroring. We should support the opposite direction as well.

Modifications:
- Implement `GitMirror#mirrorToLocalRemote()` which used to throw `UnsupportedOperationException` before.

Result:
- Close #53
- You can now enable mirroring from Central Dogma to a remote Git server.

it/src/test/java/com/linecorp/centraldogma/it/mirror/git/GitMirrorTest.java

@@ -426,16 +426,19 @@ private void pushMirrorSettings(@Nullable String localPath, @Nullable String rem
 
     private void pushMirrorSettings(String localRepo, @Nullable String localPath, @Nullable String remotePath,
                                     @Nullable String gitignore) {
+        final String localPath0 = localPath == null ? "/" : localPath;
+        final String remoteUri = gitUri + firstNonNull(remotePath, "");
         client.forRepo(projName, Project.REPO_META)
               .commit("Add /mirrors.json",
                       Change.ofJsonUpsert("/mirrors.json",
                                           "[{" +
                                           "  \"type\": \"single\"," +
                                           "  \"direction\": \"REMOTE_TO_LOCAL\"," +
                                           "  \"localRepo\": \"" + localRepo + "\"," +
-                                          (localPath != null ? "\"localPath\": \"" + localPath + "\"," : "") +
-                                          "  \"remoteUri\": \"" + gitUri + firstNonNull(remotePath, "") + '"' +
-                                          ",\"gitignore\": " + firstNonNull(gitignore, "\"\"") +
+                                          "  \"localPath\": \"" + localPath0 + "\"," +
+                                          "  \"remoteUri\": \"" + remoteUri + "\"," +
+                                          "  \"schedule\": \"0 0 0 1 1 ? 2099\"," +
+                                          "  \"gitignore\": " + firstNonNull(gitignore, "\"\"") +
                                           "}]"))
               .push().join();
     }
@@ -453,8 +456,8 @@ private void addToGitIndex(String path, String content) throws IOException, GitA
         addToGitIndex(git, gitWorkTree, path, content);
     }
 
-    private static void addToGitIndex(Git git, File gitWorkTree,
-                                      String path, String content) throws IOException, GitAPIException {
+    static void addToGitIndex(Git git, File gitWorkTree,
+                              String path, String content) throws IOException, GitAPIException {
         final File file = Paths.get(gitWorkTree.getAbsolutePath(), path.split("/")).toFile();
         file.getParentFile().mkdirs();
         Files.asCharSink(file, StandardCharsets.UTF_8).write(content);

server/src/main/java/com/linecorp/centraldogma/server/internal/mirror/DefaultMirroringService.java

@@ -138,7 +138,7 @@ public void onSuccess(@Nullable Object result) {}
 
             @Override
             public void onFailure(Throwable cause) {
-                logger.error("Git-to-CD mirroring scheduler stopped due to an unexpected exception:", cause);
+                logger.error("Git mirroring scheduler stopped due to an unexpected exception:", cause);
             }
         }, MoreExecutors.directExecutor());
     }
@@ -207,7 +207,7 @@ public void onSuccess(@Nullable Object result) {}
 
                               @Override
                               public void onFailure(Throwable cause) {
-                                  logger.warn("Unexpected Git-to-CD mirroring failure: {}", m, cause);
+                                  logger.warn("Unexpected Git mirroring failure: {}", m, cause);
                               }
                           }, MoreExecutors.directExecutor());
                       });

server/src/main/java/com/linecorp/centraldogma/server/internal/mirror/MirrorState.java

@@ -20,8 +20,10 @@
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import com.google.common.annotations.VisibleForTesting;
 
-final class MirrorState {
+@VisibleForTesting
+public final class MirrorState {
 
     private final String sourceRevision;
 
@@ -30,7 +32,8 @@ final class MirrorState {
         this.sourceRevision = requireNonNull(sourceRevision, "sourceRevision");
     }
 
-    String sourceRevision() {
+    @JsonProperty("sourceRevision")
+    public String sourceRevision() {
         return sourceRevision;
     }
 }

server/src/main/java/com/linecorp/centraldogma/server/mirror/MirrorUtil.java

@@ -61,7 +61,7 @@ public static String normalizePath(String path) {
      *
      * <p>e.g. git+ssh://foo.com/bar.git/some-path#master is split into:
      * - remoteRepoUri: git+ssh://foo.com/bar.git
-     * - remotePath:    /some-path
+     * - remotePath:    /some-path/
      * - remoteBranch:  master
      *
      * <p>e.g. dogma://foo.com/bar/qux.dogma is split into:

site/src/sphinx/concepts.rst

@@ -42,7 +42,7 @@ Concepts
   - Meta repository
 
     - A *meta repository* is a repository whose name is ``meta`` in a project. It is dedicated to store the
-      metadata related with the project it belongs to, such as Git-to-CD mirroring settings.
+      metadata related with the project it belongs to, such as Git mirroring settings.
 
 - Commit
 

site/src/sphinx/mirroring.rst

@@ -217,6 +217,11 @@ If everything was configured correctly, the repository you specified in ``localR
       "sourceRevision": "22fb176e4d8096d709d34ffe985c5f3acea83ef2"
     }
 
+Setting up a CD-to-Git mirror
+-----------------------------
+It's exactly the same as setting up a Git-to-CD mirror which is described above, except you need to specify
+``direction`` with ``LOCAL_TO_REMOTE``.
+
 Mirror limit settings
 ---------------------
 Central Dogma limits the number of files and the total size of the files in a mirror for its reliability.

site/src/sphinx/setup-configuration.rst

@@ -182,7 +182,7 @@ Core properties
 
 - ``mirroringEnabled`` (boolean)
 
-  - whether to enable Git-to-CD mirroring. It's enabled by default. For more information about mirroring,
+  - whether to enable Git mirroring. It's enabled by default. For more information about mirroring,
     refer to :ref:`mirroring`.
 
 - ``numMirroringThreads`` (integer)

testing-internal/src/main/java/com/linecorp/centraldogma/testing/internal/TestUtil.java

@@ -47,7 +47,8 @@ public static <T> void assertJsonConversion(T value, Class<T> valueType, String
     }
 
     public static String normalizedDisplayName(TestInfo testInfo) {
-        return DISALLOWED_CHARS.matcher(testInfo.getDisplayName()).replaceAll("");
+        return DISALLOWED_CHARS.matcher(testInfo.getDisplayName() + testInfo.getTestMethod().get().getName())
+                               .replaceAll("");
     }
 
     private TestUtil() {}