Support tracing on clone, fetch and ls-refs
If git protocol V2 is used clients can pass server options on clone,
fetch and ls-refs. Add support for a "trace" server option that enables
request tracing in Gerrit. E.g.:
git fetch origin -o trace=123
git ls-remote origin -o trace=456
git clone --server-option trace=789 <URL>
Note the git clone doesn't support server options by '-o' since git
clone uses '-o' to set the name of the origin.
Tracing git clone, fetch and ls-refs only works if git protocol V2 is
used. This means v2 must be enabled in:
- the repository's .git/config:
[protocol]
version = 2
- on the client side, by either passing -c protocol.version=2, or
setting globally in ~/.gitconfig:
[protocol]
version = 2
Extend existing GitProtocolV2IT integration test to pass -o trace=<num>
option. As the consequence the trace context is created with this trace
id, e.g.:
DEBUG com.google.gerrit.server.permissions.RefControl : 'user' cannot \
perform 'read' with force=false on project 'foo' for \
ref 'refs/heads/secret' [...] [CONTEXT forced=true TRACE_ID="12345" \
project="foo" ]
However, it is not clear how to verify that the trace context works as
expected.
Another open question is how we could return a generated trace ID to the
client. For now this is left as a todo, because the tracing
functionality is already usable by setting the trace server option with
an explicit trace ID (as shown in the examples above).
Change-Id: I04662a352eb9ceccdbe25eb398289badd07492e2
Signed-off-by: Edwin Kempin <ekempin@google.com>
diff --git a/Documentation/user-request-tracing.txt b/Documentation/user-request-tracing.txt
index d422dd9..b26f4c1 100644
--- a/Documentation/user-request-tracing.txt
+++ b/Documentation/user-request-tracing.txt
@@ -22,12 +22,19 @@
`--trace` option. More information about this can be found in
the link:cmd-index.html#trace[Trace] section of the
link:cmd-index.html[SSH command documentation].
-* Git: For Git pushes tracing can be enabled by setting the
- `trace` push option, the trace ID is returned in the command output.
- More information about this can be found in
- the link:user-upload.html#trace[Trace] section of the
- link:user-upload.html[upload documentation]. Tracing for Git requests
- other than Git push is not supported.
+* Git Push (requires usage of git protocol v2): For Git pushes tracing
+ can be enabled by setting the `trace` push option, the trace ID is
+ returned in the command output. More information about this can be
+ found in the link:user-upload.html#trace[Trace] section of the
+ link:user-upload.html[upload documentation].
+* Git Clone/Fetch/Ls-Remote (requires usage of git protocol v2): For
+ Git clone/fetch/ls-remote tracing can be enabled by setting the
+ `trace` server option. Use '-o trace=<TRACE-ID>' for `git fetch` and
+ `git ls-remote`, and '--server-option trace=<TRACE-ID>' for
+ `git clone`. If the `trace` server option is set without a value
+ (without trace ID) a trace ID is generated but the generated trace ID
+ is not returned to the client (hence a trace ID should always be
+ set).
When request tracing is enabled it is possible to provide an ID that
should be used as trace ID. If a trace ID is not provided a trace ID is
diff --git a/java/com/google/gerrit/httpd/GitOverHttpServlet.java b/java/com/google/gerrit/httpd/GitOverHttpServlet.java
index ff2a83d..858c173 100644
--- a/java/com/google/gerrit/httpd/GitOverHttpServlet.java
+++ b/java/com/google/gerrit/httpd/GitOverHttpServlet.java
@@ -32,6 +32,7 @@
import com.google.gerrit.server.cache.CacheModule;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.gerrit.server.git.PermissionAwareRepositoryManager;
+import com.google.gerrit.server.git.TracingHook;
import com.google.gerrit.server.git.TransferConfig;
import com.google.gerrit.server.git.UploadPackInitializer;
import com.google.gerrit.server.git.receive.AsyncReceiveCommits;
@@ -415,7 +416,11 @@
up.setPreUploadHook(
PreUploadHookChain.newChain(
Lists.newArrayList(up.getPreUploadHook(), uploadValidators)));
- next.doFilter(httpRequest, responseWrapper);
+
+ try (TracingHook tracingHook = new TracingHook()) {
+ up.setProtocolV2Hook(tracingHook);
+ next.doFilter(httpRequest, responseWrapper);
+ }
} finally {
groupAuditService.dispatch(
new HttpAuditEvent(
diff --git a/java/com/google/gerrit/server/git/TracingHook.java b/java/com/google/gerrit/server/git/TracingHook.java
new file mode 100644
index 0000000..4191373
--- /dev/null
+++ b/java/com/google/gerrit/server/git/TracingHook.java
@@ -0,0 +1,99 @@
+// Copyright (C) 2018 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.git;
+
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.common.collect.Iterables;
+import com.google.common.collect.LinkedListMultimap;
+import com.google.common.collect.ListMultimap;
+import com.google.gerrit.server.logging.TraceContext;
+import java.util.List;
+import java.util.Optional;
+import org.eclipse.jgit.transport.FetchV2Request;
+import org.eclipse.jgit.transport.LsRefsV2Request;
+import org.eclipse.jgit.transport.ProtocolV2Hook;
+
+/**
+ * Git hook for ls-refs and fetch that enables Gerrit request tracing if the user sets the 'trace'
+ * server option.
+ *
+ * <p>This hook is only invoked if Git protocol v2 is used.
+ *
+ * <p>If the 'trace' server option is specified without value, this means without providing a trace
+ * ID, a trace ID is generated, but it's not returned to the client. Hence users are advised to
+ * always provide a trace ID.
+ */
+public class TracingHook implements ProtocolV2Hook, AutoCloseable {
+ private TraceContext traceContext;
+
+ @Override
+ public void onLsRefs(LsRefsV2Request req) {
+ maybeStartTrace(req.getServerOptions());
+ }
+
+ @Override
+ public void onFetch(FetchV2Request req) {
+ maybeStartTrace(req.getServerOptions());
+ }
+
+ @Override
+ public void close() {
+ if (traceContext != null) {
+ traceContext.close();
+ }
+ }
+
+ /**
+ * Starts request tracing if 'trace' server option is set.
+ *
+ * @param serverOptionList list of provided server options
+ */
+ private void maybeStartTrace(List<String> serverOptionList) {
+ checkState(traceContext == null, "Trace was already started.");
+
+ Optional<String> traceOption = parseTraceOption(serverOptionList);
+ traceContext =
+ TraceContext.newTrace(
+ traceOption.isPresent(),
+ traceOption.orElse(null),
+ (tagName, traceId) -> {
+ // TODO(ekempin): Return trace ID to client
+ });
+ }
+
+ private Optional<String> parseTraceOption(List<String> serverOptionList) {
+ if (serverOptionList == null || serverOptionList.isEmpty()) {
+ return Optional.empty();
+ }
+
+ ListMultimap<String, String> serverOptions = LinkedListMultimap.create();
+ for (String option : serverOptionList) {
+ int e = option.indexOf('=');
+ if (e > 0) {
+ serverOptions.put(option.substring(0, e), option.substring(e + 1));
+ } else {
+ serverOptions.put(option, "");
+ }
+ }
+
+ List<String> traceValues = serverOptions.get("trace");
+ if (!traceValues.isEmpty()) {
+ return Optional.of(Iterables.getLast(traceValues));
+ }
+
+ return Optional.empty();
+ }
+}
diff --git a/java/com/google/gerrit/sshd/commands/Upload.java b/java/com/google/gerrit/sshd/commands/Upload.java
index 41323dd..87ae493 100644
--- a/java/com/google/gerrit/sshd/commands/Upload.java
+++ b/java/com/google/gerrit/sshd/commands/Upload.java
@@ -21,6 +21,7 @@
import com.google.gerrit.server.RequestInfo;
import com.google.gerrit.server.RequestListener;
import com.google.gerrit.server.git.PermissionAwareRepositoryManager;
+import com.google.gerrit.server.git.TracingHook;
import com.google.gerrit.server.git.TransferConfig;
import com.google.gerrit.server.git.UploadPackInitializer;
import com.google.gerrit.server.git.validators.UploadValidationException;
@@ -83,13 +84,14 @@
for (UploadPackInitializer initializer : uploadPackInitializers) {
initializer.init(projectState.getNameKey(), up);
}
- try (TraceContext traceContext = TraceContext.open()) {
+ try (TraceContext traceContext = TraceContext.open();
+ TracingHook tracingHook = new TracingHook()) {
RequestInfo requestInfo =
RequestInfo.builder(RequestInfo.RequestType.GIT_UPLOAD, user, traceContext)
.project(projectState.getNameKey())
.build();
requestListeners.runEach(l -> l.onRequest(requestInfo));
-
+ up.setProtocolV2Hook(tracingHook);
up.upload(in, out, err);
session.setPeerAgent(up.getPeerUserAgent());
} catch (UploadValidationException e) {
diff --git a/javatests/com/google/gerrit/integration/git/GitProtocolV2IT.java b/javatests/com/google/gerrit/integration/git/GitProtocolV2IT.java
index 4314a7a..ece4d4a 100644
--- a/javatests/com/google/gerrit/integration/git/GitProtocolV2IT.java
+++ b/javatests/com/google/gerrit/integration/git/GitProtocolV2IT.java
@@ -47,7 +47,7 @@
private final String[] SSH_KEYGEN_CMD =
new String[] {"ssh-keygen", "-t", "rsa", "-q", "-P", "", "-f"};
private final String[] GIT_LS_REMOTE =
- new String[] {"git", "-c", "protocol.version=2", "ls-remote"};
+ new String[] {"git", "-c", "protocol.version=2", "ls-remote", "-o", "trace=12345"};
private final String GIT_SSH_COMMAND =
"ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i";
