Allow to configure base via coordinates (and CLI argument)

This closes bndtools#5721

Signed-off-by: Konrad Windszus <kwin@apache.org>

maven-plugins/bnd-baseline-maven-plugin/README.md

@@ -87,14 +87,23 @@ version artifact which matches these rules will be used as the baseline.
 By default the `bnd-baseline-maven-plugin` will use information from the
 current project to set its search parameters, however sometimes an artifact
 will move or change name over time, or a particular version should be 
-targeted. In this case the search parameters can be overridden. If a 
+targeted. In this case the search parameters can be overridden through {@code baseCoordinates} (since version 7.0.0)
+or {@code base} (the former taking precedence). If a 
 search parameter is omitted then it will take its default value:
 
+    <configuration>
+        <baseCoordinates>${a.different.groupId}:${a.different.artifactId}:${single.version.or.version.range}</baseCoordinates>
+    </configuration>
+
+or
+
     <configuration>
         <base>
             <groupId>${a.different.groupId}</groupId>
             <artifactId>${a.different.artifactId}</artifactId>
             <version>${single.version.or.version.range}</version>
+            <classifier>${an.optional.classifier}</version>
+            <extension>${an.optional.extension}</extension>
         </base>
     </configuration>
 
@@ -187,6 +196,7 @@ Note though that this will also completely ignore package removals, as in that c
 
 |Configuration Property | Description |
 | ---                   | ---         |
+|`baseCoordinates`       | The Maven coordinates of the base artifact in the format `<groupId>:<artifactId>[:<extension>[:<classifier>]]:<version>}`. If set, takes precedence over {@code base}. Override with property `bnd.baseline.baseCoordinates`. Available since version 7.0.0 |
 |`base`                 | See [Changing the baseline search parameters](#changing-the-baseline-search-parameters). _Defaults to the highest version of the project's artifact that is less than the version of the project's artifact._|
 |`failOnMissing`        | See [Fail on missing baseline](#fail-on-missing-baseline). _Defaults to `true`._ Override with property `bnd.baseline.fail.on.missing`.|
 |`includeDistributionManagement`| See [Include Distribution Management](#include-distribution-management). _Defaults to `true`._ Override with property `bnd.baseline.include.distribution.management`.|

maven-plugins/bnd-baseline-maven-plugin/src/it/invalid-with-provider/invoker.properties

@@ -1,4 +1,4 @@
-invoker.goals=--no-transfer-progress verify
+invoker.goals=--no-transfer-progress verify -Dbnd.baseline.baseCoordinates=biz.aQute.bnd-test:valid-no-previous:1.0.1
 
 # Run mvn with --debug for debug logging
 #invoker.debug=true

maven-plugins/bnd-baseline-maven-plugin/src/it/invalid-with-provider/pom.xml

@@ -28,9 +28,7 @@
 				<groupId>biz.aQute.bnd</groupId>
 				<artifactId>bnd-baseline-maven-plugin</artifactId>
 				<configuration>
-					<base>
-						<artifactId>valid-no-previous</artifactId>
-					</base>
+					<!-- base configured via CLI argument -->
 					<includeDistributionManagement>true</includeDistributionManagement>
 					<continueOnError>true</continueOnError>
 					<fullReport>true</fullReport>

maven-plugins/bnd-baseline-maven-plugin/src/main/java/aQute/bnd/maven/baseline/plugin/Base.java

@@ -1,5 +1,8 @@
 package aQute.bnd.maven.baseline.plugin;
 
+import org.eclipse.aether.artifact.Artifact;
+import org.eclipse.aether.artifact.DefaultArtifact;
+
 public class Base {
 
 	private String	groupId;
@@ -12,6 +15,14 @@ public class Base {
 
 	private String	extension;
 
+	public void setFromCoordinates(String coordinates) {
+		Artifact artifact = new DefaultArtifact(coordinates);
+		setGroupId(artifact.getGroupId());
+		setArtifactId(artifact.getArtifactId());
+		setVersion(artifact.getVersion());
+		setClassifier(artifact.getClassifier());
+		setExtension(artifact.getExtension());
+	}
 	public String getGroupId() {
 		return groupId;
 	}

maven-plugins/bnd-baseline-maven-plugin/src/main/java/aQute/bnd/maven/baseline/plugin/BaselineMojo.java

@@ -72,7 +72,15 @@ public class BaselineMojo extends AbstractMojo {
 	@Parameter(property = "bnd.baseline.continue.on.error", defaultValue = "false")
 	private boolean					continueOnError;
 
-	@Parameter
+	/**
+	 * The Maven coordinates of the base artifact in the format
+	 * {@code <groupId>:<artifactId>[:<extension>[:<classifier>]]:<version>}. If
+	 * set, takes precedence over {@link #base}.
+	 */
+	@Parameter(property = "bnd.baseline.baseCoordinates")
+	private String					baseCoordinates;
+
+	@Parameter(required = false)
 	private Base					base;
 
 	@Parameter(required = false, property = "bnd.baseline.diffignores")
@@ -164,6 +172,9 @@ private void setupBase(Artifact artifact) {
 		if (base == null) {
 			base = new Base();
 		}
+		if (baseCoordinates != null && !baseCoordinates.isBlank()) {
+			base.setFromCoordinates(baseCoordinates);
+		}
 		if (base.getGroupId() == null || base.getGroupId()
 			.isEmpty()) {
 			base.setGroupId(project.getGroupId());

maven-plugins/bnd-plugin-parent/pom.xml

@@ -216,6 +216,19 @@
 		</dependency>
 	</dependencies>
 
+	<repositories>
+		<repository>
+			<id>bnd-snapshots</id>
+			<releases>
+				<enabled>false</enabled>
+			</releases>
+			<snapshots>
+				<enabled>true</enabled>
+			</snapshots>
+			<url>https://bndtools.jfrog.io/bndtools/libs-snapshot/</url>
+		</repository>
+	</repositories>
+
 	<build>
 		<pluginManagement>
 			<plugins>