Add markdown link check (#74)

Resolves #65

Author: trask

.github/config/markdown-link-check-config.json

@@ -0,0 +1,11 @@
+{
+  "retryOn429" : true,
+  "ignorePatterns" : [
+    {
+      "pattern" : "^http://localhost:.*"
+    },
+    {
+      "pattern" : "^http://0\\.0\\.0\\.0:.*"
+    }
+  ]
+}

.github/scripts/markdown-link-check-with-retry.sh

@@ -0,0 +1,17 @@
+#!/bin/bash -e
+
+# this script helps to reduce sporadic link check failures by retrying at a file-by-file level
+
+retry_count=3
+
+for file in "$@"; do
+  for i in $(seq 1 $retry_count); do
+    if markdown-link-check --config "$(dirname "$0")/../config/markdown-link-check-config.json" \
+                           "$file"; then
+      break
+    elif [[ $i -eq $retry_count ]]; then
+      exit 1
+    fi
+    sleep 5
+  done
+done

.github/workflows/build.yml

@@ -43,6 +43,10 @@ jobs:
 
       - run: java -cp sdk-usage/build/libs/opentelemetry-examples-sdk-usage-0.1.0-SNAPSHOT-all.jar io.opentelemetry.sdk.example.ConfigureSpanProcessorExample
 
+  # this is not a required check to avoid blocking pull requests if external links break
+  markdown-link-check:
+    uses: ./.github/workflows/reusable-markdown-link-check.yml
+
   required-status-check:
     needs:
       - gradle-wrapper-validation

.github/workflows/reusable-markdown-link-check.yml

@@ -0,0 +1,19 @@
+name: Reusable - Markdown link check
+
+on:
+  workflow_call:
+
+jobs:
+  markdown-link-check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Install markdown-link-check
+        run: npm install -g markdown-link-check
+
+      - name: Run markdown-link-check
+        run: |
+          find . -type f \
+                 -name '*.md' \
+               | xargs .github/scripts/markdown-link-check-with-retry.sh

jaeger/README.md

@@ -34,4 +34,4 @@ java -cp build/libs/opentelemetry-examples-jaeger-0.1.0-SNAPSHOT-all.jar io.open
 
 Navigate to http://localhost:16686
 
-[jaeger]:[https://www.jaegertracing.io/docs/1.16/getting-started/
+[jaeger]: https://www.jaegertracing.io/docs/1.16/getting-started/

micrometer-shim/README.md

@@ -1,7 +1,7 @@
 # Micrometer Shim Example
 
 This example demonstrates a typical use case
-of [micrometer1-shim](https://github.com/open-telemetry/opentelemetry-java/tree/main/micrometer1-shim).
+of [micrometer shim](https://github.com/open-telemetry/opentelemetry-java-instrumentation/tree/main/instrumentation/micrometer/micrometer-1.5/library).
 
 It consists of a spring boot application with: