Fix dead links and add checker to detect them (#6394)

.dlc.json

@@ -0,0 +1,18 @@
+{
+  "ignorePatterns": [
+    {
+      "pattern": "^http://localhost"
+    },
+    {
+      "pattern": "^https://github.com/apache/skywalking/blob/master/changes/changes-x.y.z.md$"
+    }
+  ],
+  "timeout": "10s",
+  "retryOn429": true,
+  "retryCount": 10,
+  "fallbackRetryDelay": "1000s",
+  "aliveStatusCodes": [
+    200,
+    401
+  ]
+}

.github/actions/skip/action.yml

@@ -28,6 +28,8 @@ inputs:
       "*.md"
       "skywalking-ui"
       ".asf.yaml"
+      ".dlc.yaml"
+      ".licenserc.yaml"
 runs:
   using: "composite"
   steps:

.github/workflows/dead-link-checker.yaml

@@ -0,0 +1,32 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+name: Dead Link Checker
+
+on:
+  pull_request:
+
+jobs:
+  CheckDeadLinks:
+    runs-on: ubuntu-18.04
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@v2
+      - run: sudo npm install -g markdown-link-check
+      - run: |
+          for file in $(find . -name "*.md"); do
+            markdown-link-check -c .dlc.json -q "$file"
+          done

CODE_OF_CONDUCT.md

@@ -71,7 +71,7 @@ This statement thanks the following, on which it draws for content and inspirati
 
 * [CouchDB Project Code of conduct](http://couchdb.apache.org/conduct.html)
 * [Fedora Project Code of Conduct](http://fedoraproject.org/code-of-conduct)
-* [Speak Up! Code of Conduct](http://speakup.io/coc.html)
+* [Speak Up! Code of Conduct](https://code-of-conduct.roche.com/en/speak-up.html)
 * [Django Code of Conduct](https://www.djangoproject.com/conduct/)
 * [Debian Code of Conduct](http://www.debian.org/vote/2014/vote_002)
 * [Twitter Open Source Code of Conduct](https://github.com/twitter/code-of-conduct/blob/master/code-of-conduct.md)

README.md

@@ -101,4 +101,4 @@ SkyWalking enriches the <a href="https://landscape.cncf.io/landscape=observabili
 </p>
 
 # License
-[Apache 2.0 License.](/LICENSE)
+[Apache 2.0 License.](LICENSE)

changes/changes-8.4.0.md

@@ -61,7 +61,7 @@ Release Notes.
 * Improve query performance in storage-influxdb-plugin.
 * Fix the uuid field in GRPCConfigWatcherRegister is not updated.
 * Support Envoy {AccessLog,Metrics}Service API V3.
-* Adopt the [MAL](docs/en/concepts-and-designs/mal.md) in Envoy metrics service analyzer.
+* Adopt the [MAL](../docs/en/concepts-and-designs/mal.md) in Envoy metrics service analyzer.
 * Fix the priority setting doesn't work of the ALS analyzers.
 * Fix bug that `endpoint-name-grouping.yml` is not customizable in Dockerized case.
 * Fix bug that istio version metric type on UI template mismatches the otel rule.

docs/en/concepts-and-designs/probe-introduction.md

@@ -33,6 +33,6 @@ like logs, just save them, and build the links between traces and metrics, like
 
 ## What is next?
 - Learn the SkyWalking supported probes in [Service auto instrument agent](service-agent.md), [Manual instrument SDK](manual-sdk.md),
-[Service Mesh probe](service-mesh-probe.md) and [Zipkin receiver](trace-receiver.md).
+[Service Mesh probe](service-mesh-probe.md) and [Zipkin receiver](../setup/backend/backend-receivers.md#zipkin-receiver).
 - After understand the probe, read [backend overview](backend-overview.md) for understanding analysis and persistence.
 

docs/en/guides/Java-Plugin-Development-Guide.md

@@ -321,7 +321,7 @@ tomcat-7.x/8.x=TomcatInstrumentation
      return witnessMethodList;
    }
    ```
-   For more example, see [WitnessTest.java](/apm-sniffer/apm-agent-core/src/test/java/org/apache/skywalking/apm/agent/core/plugin/witness/WitnessTest.java)
+   For more example, see [WitnessTest.java](../../../apm-sniffer/apm-agent-core/src/test/java/org/apache/skywalking/apm/agent/core/plugin/witness/WitnessTest.java)
 
    
 

docs/en/protocols/Browser-HTTP-API-Protocol.md

@@ -41,7 +41,7 @@ Http Status: 204
 
 ## Error Log Report
 
-Detail information about data format can be found in [BrowserPerf.proto](https://github.com/apache/skywalking-data-collect-protocol/blob/master/Browser/BrowserPerf.proto).
+Detail information about data format can be found in [BrowserPerf.proto](https://github.com/apache/skywalking-data-collect-protocol/blob/master/browser/BrowserPerf.proto).
 
 ### POST http://localhost:12800/browser/errorLogs
 

docs/en/protocols/JVM-Protocol.md

@@ -2,4 +2,4 @@
 ## Abstract
 Uplink the JVM metrics, including PermSize, HeapSize, CPU, Memory, etc., every second.
 
-[gRPC service define](https://github.com/apache/skywalking-data-collect-protocol/blob/v2.0/JVMMetricsService.proto)
+[gRPC service define](https://github.com/apache/skywalking-data-collect-protocol/blob/master/language-agent/JVMMetric.proto)

docs/en/setup/envoy/metrics_service_setting.md

@@ -50,7 +50,7 @@ static_resources:
 
 A more complete static configuration, can be observed [here](config.yaml).
 
-Note that Envoy can also be configured dynamically through [xDS Protocol](https://github.com/envoyproxy/data-plane-api/blob/master/XDS_PROTOCOL.md).
+Note that Envoy can also be configured dynamically through [xDS Protocol](https://github.com/envoyproxy/data-plane-api/blob/main/xds_protocol.rst).
 
 As mentioned above, SkyWalking also builds the topology of services from the metrics, this is because Envoy also carries the service metadata along with the metrics, to feed the Envoy such metadata, another configuration part is as follows:
 
@@ -65,7 +65,7 @@ node:
 
 ## Configure Envoy to send metrics to SkyWalking with Istio
 
-Typically, Envoy can be also used under Istio's control, where the configurations are much more simple because Istio composes the configurations for you and sends them to Envoy via [xDS Protocol](https://github.com/envoyproxy/data-plane-api/blob/master/XDS_PROTOCOL.md).
+Typically, Envoy can be also used under Istio's control, where the configurations are much more simple because Istio composes the configurations for you and sends them to Envoy via [xDS Protocol](https://github.com/envoyproxy/data-plane-api/blob/master/xds_protocol.rst).
 Istio also automatically injects the metadata such as service name and instance name into the bootstrap configurations.
 
 Under this circumstance, emitting the metrics to SyWalking is as simple as adding the option `--set meshConfig.defaultConfig.envoyMetricsService.address=<skywalking.address.port.11800>` to Istio install command, for example:

docs/en/setup/service-agent/java-agent/README.md

@@ -134,7 +134,7 @@ property key | Description | Default |
 `plugin.solrj.trace_statement`|If true, trace all the query parameters(include deleteByIds and deleteByQuery) in Solr query request, default is false.|`false`|
 `plugin.solrj.trace_ops_params`|If true, trace all the operation parameters in Solr request, default is false.|`false`|
 `plugin.light4j.trace_handler_chain`|If true, trace all middleware/business handlers that are part of the Light4J handler chain for a request.|false|
-`plugin.opgroup.*`|Support operation name customize group rules in different plugins. Read [Group rule supported plugins](op_name_group_rule.md)|Not set|
+`plugin.opgroup.*`|Support operation name customize group rules in different plugins. Read [Group rule supported plugins](../../backend/endpoint-grouping-rules.md)|Not set|
 `plugin.springtransaction.simplify_transaction_definition_name`|If true, the transaction definition name will be simplified.|false|
 `plugin.jdkthreading.threading_class_prefixes` | Threading classes (`java.lang.Runnable` and `java.util.concurrent.Callable`) and their subclasses, including anonymous inner classes whose name match any one of the `THREADING_CLASS_PREFIXES` (splitted by `,`) will be instrumented, make sure to only specify as narrow prefixes as what you're expecting to instrument, (`java.` and `javax.` will be ignored due to safety issues) | Not set |
 `plugin.tomcat.collect_http_params`| This config item controls that whether the Tomcat plugin should collect the parameters of the request. Also, activate implicitly in the profiled trace. | `false` |

docs/en/setup/service-agent/java-agent/Supported-list.md

@@ -26,7 +26,7 @@ metrics based on the tracing data.
   * [Apache httpcomponent HttpClient](http://hc.apache.org/) 2.0 -> 3.1, 4.2, 4.3
   * [Spring RestTemplete](https://github.com/spring-projects/spring-framework) 4.x
   * [Jetty Client](http://www.eclipse.org/jetty/) 9
-  * [Apache httpcomponent AsyncClient](https://hc.apache.org/httpcomponents-asyncclient-dev/) 4.x
+  * [Apache httpcomponent AsyncClient](https://hc.apache.org/httpcomponents-asyncclient-4.1.x/) 4.x
   * [AsyncHttpClient](https://github.com/AsyncHttpClient/async-http-client) 2.x
   * JRE HttpURLConnection (Optional²)
 * HTTP Gateway