JVMCBC-1652 Read library version from version.properties

instead of JAR manifest.

Motivation
----------
When the client library is shaded, its JAR manifest
may be discarded or corrupted. In this scenario,
reading the version from a dedicated class path
resource is more reliable.

A secondary benefit: unlike the manifest-based solution,
reading a class path resource does not require building a JAR.

Modifications
-------------
Define a `src/main/resources-filtered` resource directory
in the parent POM.

Add a `version.properties` resource to each project that
requires version introspection.

Change-Id: I73e39587934028a614cf543ed7fe0235e8395383
Reviewed-on: https://review.couchbase.org/c/couchbase-jvm-clients/+/228834
Tested-by: Build Bot <[email protected]>
Reviewed-by: Michael Reiche <[email protected]>

Author: dnault

columnar-java-client/src/main/resources-filtered/com/couchbase/columnar/client/java/version.properties

@@ -0,0 +1,2 @@
+version=${project.version}
+gitHash=${buildNumber}

core-io/src/main/java/com/couchbase/client/core/env/VersionAndGitHash.java

@@ -17,11 +17,19 @@
 package com.couchbase.client.core.env;
 
 import com.couchbase.client.core.annotation.Stability;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Properties;
 
 import static java.util.Objects.requireNonNull;
 
 @Stability.Internal
 public class VersionAndGitHash {
+  private static final Logger log = LoggerFactory.getLogger(VersionAndGitHash.class);
+
   private final String version;
   private final String gitHash;
 
@@ -46,13 +54,24 @@ public String toString() {
   }
 
   public static VersionAndGitHash from(Class<?> classInSamePackageAsVersionMetadata) {
-    String value = classInSamePackageAsVersionMetadata.getPackage().getImplementationVersion();
-    if (value == null) {
+    String resourceName = "version.properties";
+    try (InputStream is = classInSamePackageAsVersionMetadata.getResourceAsStream(resourceName)) {
+      if (is == null) {
+        log.warn("Resource '{}' not found in package {}", resourceName, classInSamePackageAsVersionMetadata.getPackage());
+        return UNKNOWN;
+      }
+      Properties properties = new Properties();
+      properties.load(is);
+      String version = properties.getProperty("version");
+      String gitHash = properties.getProperty("gitHash");
+
+      return new VersionAndGitHash(
+        version == null ? "0.0.0" : version,
+        gitHash == null ? "" : gitHash
+      );
+    } catch (IOException e) {
+      log.warn("Failed to load '{}' from {}", resourceName, classInSamePackageAsVersionMetadata, e);
       return UNKNOWN;
     }
-    String[] components = value.split("\\+", 2);
-    return components.length == 1
-      ? new VersionAndGitHash(value, "")
-      : new VersionAndGitHash(components[0], components[1]);
   }
 }

core-io/src/main/resources-filtered/com/couchbase/client/core/version.properties

@@ -0,0 +1,2 @@
+version=${project.version}
+gitHash=${buildNumber}

java-client/src/main/resources-filtered/com/couchbase/client/java/version.properties

@@ -0,0 +1,2 @@
+version=${project.version}
+gitHash=${buildNumber}

kotlin-client/src/main/resources-filtered/com/couchbase/client/kotlin/version.properties

@@ -0,0 +1,2 @@
+version=${project.version}
+gitHash=${buildNumber}

metrics-opentelemetry/src/main/resources-filtered/com/couchbase/client/metrics/opentelemetry/version.properties

@@ -0,0 +1,2 @@
+version=${project.version}
+gitHash=${buildNumber}

pom.xml

@@ -200,6 +200,16 @@
     </modules>
 
     <build>
+        <resources>
+            <resource>
+                <directory>src/main/resources-filtered</directory>
+                <filtering>true</filtering>
+            </resource>
+            <resource>
+                <directory>src/main/resources</directory>
+            </resource>
+        </resources>
+
         <pluginManagement>
             <plugins>
                 <!-- Declare flatten in pluginManagement so modules that also use shade plugin

scala-client/src/main/resources-filtered/com/couchbase/client/scala/version.properties

@@ -0,0 +1,2 @@
+version=${project.version}
+gitHash=${buildNumber}