feat(about): reimplement git build info in /health (#589)

pom.xml

@@ -51,6 +51,7 @@
     <quarkus-quinoa.version>2.2.5</quarkus-quinoa.version>
     <io.netty.version>4.1.108.Final</io.netty.version>
     <org.codehaus.mojo.build.helper.plugin.version>3.6.0</org.codehaus.mojo.build.helper.plugin.version>
+    <org.codehaus.mojo.exec.plugin.version>3.3.0</org.codehaus.mojo.exec.plugin.version>
     <assembly-plugin.version>3.7.1</assembly-plugin.version>
 
     <com.github.spotbugs.version>4.8.6</com.github.spotbugs.version>
@@ -345,6 +346,29 @@
           </annotationProcessorPaths>
         </configuration>
       </plugin>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>${org.codehaus.mojo.exec.plugin.version}</version>
+        <executions>
+          <execution>
+            <id>generate-git-version</id>
+            <phase>generate-resources</phase>
+            <goals>
+              <goal>exec</goal>
+            </goals>
+            <configuration>
+              <executable>git</executable>
+              <arguments>
+                <argument>rev-parse</argument>
+                <argument>--verify</argument>
+                <argument>HEAD</argument>
+              </arguments>
+              <outputFile>${project.build.directory}/classes/META-INF/gitinfo</outputFile>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>build-helper-maven-plugin</artifactId>

src/main/java/io/cryostat/BuildInfo.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright The Cryostat Authors.
+ *
+ * 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 io.cryostat;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import jakarta.enterprise.context.ApplicationScoped;
+import jakarta.inject.Inject;
+import org.jboss.logging.Logger;
+
+@ApplicationScoped
+public class BuildInfo {
+
+    private static final String RESOURCE_LOCATION = "META-INF/gitinfo";
+
+    @Inject Logger logger;
+
+    private final GitInfo gitinfo = new GitInfo();
+
+    @JsonProperty("git")
+    public GitInfo getGitInfo() {
+        return gitinfo;
+    }
+
+    public class GitInfo {
+        public String getHash() {
+            try (BufferedReader br =
+                    new BufferedReader(
+                            new InputStreamReader(
+                                    Thread.currentThread()
+                                            .getContextClassLoader()
+                                            .getResourceAsStream(RESOURCE_LOCATION),
+                                    StandardCharsets.UTF_8))) {
+                return br.lines()
+                        .findFirst()
+                        .orElseThrow(
+                                () ->
+                                        new IllegalStateException(
+                                                String.format(
+                                                        "Resource file %s is empty",
+                                                        RESOURCE_LOCATION)))
+                        .trim();
+            } catch (Exception e) {
+                logger.warn("Version retrieval exception", e);
+                return "unknown";
+            }
+        }
+    }
+}

src/main/java/io/cryostat/Health.java

@@ -64,8 +64,9 @@ class Health {
     @ConfigProperty(name = ConfigProperties.REPORTS_SIDECAR_URL)
     String reportsClientURL;
 
-    @Inject Logger logger;
+    @Inject BuildInfo buildInfo;
     @Inject WebClient webClient;
+    @Inject Logger logger;
 
     @GET
     @Blocking
@@ -98,6 +99,8 @@ public Response health() {
                         Map.of(
                                 "cryostatVersion",
                                 String.format("v%s", version),
+                                "build",
+                                buildInfo,
                                 "dashboardConfigured",
                                 dashboardURL.isPresent(),
                                 "dashboardAvailable",