add major/minor version-aware HelpUrl builder

logstash-core/build.gradle

@@ -57,6 +57,7 @@ def versionMap = (Map) (new Yaml()).load(new File("$projectDir/../versions.yml")
 
 description = """Logstash Core Java"""
 
+String logstashCoreVersion = versionMap['logstash-core']
 String jacksonVersion = versionMap['jackson']
 String jacksonDatabindVersion = versionMap['jackson-databind']
 String jrubyVersion = versionMap['jruby']['version']
@@ -183,6 +184,23 @@ artifacts {
     }
 }
 
+task generateVersionInfoResources(type: DefaultTask) {
+    ext.outDir = layout.buildDirectory.dir("generated-resources/version-info").get()
+
+    inputs.property("version-info:logstash-core", logstashCoreVersion)
+    outputs.dir(ext.outDir)
+
+    doLast {
+        mkdir outDir;
+        def resourceFile = outDir.file('version-info.properties').asFile
+        resourceFile.text = "logstash-core: ${logstashCoreVersion}"
+    }
+}
+sourceSets {
+    main { output.dir(generateVersionInfoResources.outputs.files) }
+}
+processResources.dependsOn generateVersionInfoResources
+
 configurations {
     provided
 }

logstash-core/src/main/java/org/logstash/Logstash.java

@@ -26,6 +26,7 @@
 import java.io.PrintStream;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Properties;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -45,6 +46,25 @@
  */
 public final class Logstash implements Runnable, AutoCloseable {
 
+    public static final String VERSION_FULL;
+    public static final String VERSION_MAJOR;
+    public static final String VERSION_MINOR;
+    public static final String VERSION_PATCH;
+
+    static {
+        final Properties properties = new Properties();
+        try {
+            properties.load(Logstash.class.getResourceAsStream("/version-info.properties"));
+            VERSION_FULL = properties.getProperty("logstash-core");
+            final String[] versions = VERSION_FULL.split("\\.");
+            VERSION_MAJOR = versions[0];
+            VERSION_MINOR = versions[1];
+            VERSION_PATCH = versions[2];
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     private static final Logger LOGGER = LogManager.getLogger(Logstash.class);
 
     /**

logstash-core/src/main/java/org/logstash/health/HelpUrl.java

@@ -0,0 +1,50 @@
+package org.logstash.health;
+
+import org.logstash.Logstash;
+
+import java.util.Objects;
+
+public class HelpUrl {
+    static final String BASE_URL;
+    static {
+        final String versionAnchor;
+        if (Integer.parseInt(Logstash.VERSION_MAJOR) >= 9) {
+            versionAnchor = "master";
+        } else {
+            versionAnchor = String.format("%s.%s", Logstash.VERSION_MAJOR, Logstash.VERSION_MINOR);
+        }
+        BASE_URL = String.format("https://www.elastic.co/guide/en/logstash/%s/", versionAnchor);
+    }
+
+    public HelpUrl(final String page) {
+        this(page, null);
+    }
+
+    public HelpUrl withAnchor(final String anchor) {
+        return new HelpUrl(this.page, anchor);
+    }
+
+    private HelpUrl(final String page, final String anchor) {
+        Objects.requireNonNull(page, "page cannot be null");
+        this.page = page;
+        this.anchor = anchor;
+    }
+
+    private final String page;
+    private final String anchor;
+
+    private transient String resolved;
+
+    @Override
+    public String toString() {
+        if (resolved == null) {
+            final StringBuilder sb = new StringBuilder(BASE_URL);
+            sb.append(page).append(".html");
+            if (anchor != null) {
+                sb.append("#").append(anchor);
+            }
+            resolved = sb.toString();
+        }
+        return resolved;
+    }
+}

logstash-core/src/main/java/org/logstash/health/PipelineIndicator.java

@@ -111,6 +111,8 @@ static class StatusProbe implements Probe<Details> {
                 .withDescription("the pipeline is not currently processing")
                 .withAdditionalImpactArea(ImpactArea.PIPELINE_EXECUTION);
 
+        static final HelpUrl HELP_URL = new HelpUrl("health-report-pipeline-status");
+
         @Override
         public Analysis analyze(final Details details) {
             switch (details.getStatus().getState()) {
@@ -120,7 +122,8 @@ public Analysis analyze(final Details details) {
                             .withDiagnosis(db -> db
                                     .withId(diagnosisId("loading"))
                                     .withCause("pipeline is loading")
-                                    .withAction("if pipeline does not come up quickly, you may need to check the logs to see if it is stalled"))
+                                    .withAction("if pipeline does not come up quickly, you may need to check the logs to see if it is stalled")
+                                    .withHelpUrl(HELP_URL.withAnchor("loading").toString()))
                             .withImpact(NOT_PROCESSING.withSeverity(1).withDescription("pipeline is loading").build())
                             .build();
                 case RUNNING:
@@ -133,7 +136,8 @@ public Analysis analyze(final Details details) {
                             .withDiagnosis(db -> db
                                     .withId(diagnosisId("finished"))
                                     .withCause("pipeline has finished running because its inputs have been closed and events have been processed")
-                                    .withAction("if you expect this pipeline to run indefinitely, you will need to configure its inputs to continue receiving or fetching events"))
+                                    .withAction("if you expect this pipeline to run indefinitely, you will need to configure its inputs to continue receiving or fetching events")
+                                    .withHelpUrl(HELP_URL.withAnchor("finished").toString()))
                             .withImpact(NOT_PROCESSING.withSeverity(10).withDescription("pipeline has finished running").build())
                             .build();
                 case TERMINATED:
@@ -142,7 +146,8 @@ public Analysis analyze(final Details details) {
                             .withDiagnosis(db -> db
                                     .withId(diagnosisId("terminated"))
                                     .withCause("pipeline is not running, likely because it has encountered an error")
-                                    .withAction("view logs to determine the cause of abnormal pipeline shutdown"))
+                                    .withAction("view logs to determine the cause of abnormal pipeline shutdown")
+                                    .withHelpUrl(HELP_URL.withAnchor("terminated").toString()))
                             .withImpact(NOT_PROCESSING.withSeverity(1).build())
                             .build();
                 case UNKNOWN:
@@ -151,8 +156,9 @@ public Analysis analyze(final Details details) {
                             .withStatus(YELLOW)
                             .withDiagnosis(db -> db
                                     .withId(diagnosisId("unknown"))
-                                    .withCause("pipeline is not known; it may have been recently deleted")
-                                    .withAction("check logs"))
+                                    .withCause("pipeline is not known; it may have been recently deleted or failed to start")
+                                    .withAction("view logs to determine if the pipeline failed to start")
+                                    .withHelpUrl(HELP_URL.withAnchor("unknown").toString()))
                             .withImpact(NOT_PROCESSING.withSeverity(2).build())
                             .build();
             }