[fix apache#8089] expose PulsarAdmin client through Function Context (a…

…pache#9246)

Fixes apache#8089

### Motivation

apache#8089 addressed that making pulsar admin client api calls is conflict with Jersey library. This PR expose `PulsarAdmin` client through `Function Context`, so the function implementers can use PulsarAdmin to do whatever they want to do.

### Modifications

- add `getPulsarAdmin()` and `getPulsarAdmin(String clusterName)` in function `Context` 
- add implementation of above interface in `ContextImpl`
- add passing `pulsarWebServiceUrl` to function runtimes
- add passing `pulsarWebServiceUrl` to `LocalRunner` / `JavaInstanceStarter`
- add `"--web-service-url"` parameter to `LocalRunner` admin command
- add unit tests
- add example function
- add `exposeAdminClientEnabled` in `functions_worker.yml`

conf/functions_worker.yml

@@ -104,6 +104,8 @@ assignmentWriteMaxRetries: 60
 instanceLivenessCheckFreqMs: 30000
 # Frequency how often worker performs compaction on function-topics
 topicCompactionFrequencySec: 1800
+# should the function context have pulsar admin client exposed? Default is disabled.
+exposeAdminClientEnabled: false
 
 
 ###############################

pom.xml

@@ -1656,6 +1656,7 @@ flexible messaging model and an intuitive client API.</description>
         <module>pulsar-client</module>
         <module>pulsar-client-shaded</module>
         <module>pulsar-client-1x-base</module>
+        <module>pulsar-client-admin-api</module>
         <module>pulsar-client-admin</module>
         <module>pulsar-client-admin-shaded</module>
         <module>pulsar-client-tools</module>
@@ -1717,6 +1718,7 @@ flexible messaging model and an intuitive client API.</description>
         <module>pulsar-broker</module>
         <module>pulsar-client-api</module>
         <module>pulsar-client</module>
+        <module>pulsar-client-admin-api</module>
         <module>pulsar-client-admin</module>
         <module>pulsar-client-tools</module>
         <module>pulsar-client-tools-test</module>

pulsar-broker/src/test/java/org/apache/pulsar/broker/loadbalance/LoadBalancerTest.java

@@ -63,6 +63,7 @@
 import org.apache.pulsar.broker.loadbalance.impl.SimpleResourceUnit;
 import org.apache.pulsar.client.admin.PulsarAdmin;
 import org.apache.pulsar.client.admin.internal.NamespacesImpl;
+import org.apache.pulsar.client.admin.internal.PulsarAdminImpl;
 import org.apache.pulsar.common.naming.NamespaceName;
 import org.apache.pulsar.common.naming.TopicName;
 import org.apache.pulsar.common.policies.data.AutoFailoverPolicyData;
@@ -635,7 +636,7 @@ public void testNamespaceBundleAutoSplit() throws Exception {
 
         // fake Namespaces Admin
         NamespacesImpl namespaceAdmin = mock(NamespacesImpl.class);
-        setObjectField(PulsarAdmin.class, pulsarServices[0].getAdminClient(), "namespaces", namespaceAdmin);
+        setObjectField(PulsarAdminImpl.class, pulsarServices[0].getAdminClient(), "namespaces", namespaceAdmin);
 
         // create load report
         // namespace 01~09 need to be split

pulsar-client-admin-api/.gitignore

@@ -0,0 +1 @@
+/target/

pulsar-client-admin-api/pom.xml

@@ -0,0 +1,73 @@
+<!--
+
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you 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.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.apache.pulsar</groupId>
+        <artifactId>pulsar</artifactId>
+        <version>2.8.0-SNAPSHOT</version>
+        <relativePath>..</relativePath>
+    </parent>
+
+    <artifactId>pulsar-client-admin-api</artifactId>
+    <name>Pulsar Client Admin :: API</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>pulsar-common</artifactId>
+            <version>${project.parent.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>pulsar-client-original</artifactId>
+            <version>${project.parent.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>pulsar-package-core</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-checkstyle-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>checkstyle</id>
+                        <phase>verify</phase>
+                        <goals>
+                            <goal>check</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

pulsar-client-admin-api/src/main/java/org/apache/pulsar/client/admin/PulsarAdmin.java

@@ -0,0 +1,166 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.pulsar.client.admin;
+
+import java.io.Closeable;
+import org.apache.pulsar.client.admin.utils.DefaultImplementation;
+import org.apache.pulsar.client.impl.conf.ClientConfigurationData;
+import org.apache.pulsar.common.classification.InterfaceAudience;
+import org.apache.pulsar.common.classification.InterfaceStability;
+
+@InterfaceAudience.Public
+@InterfaceStability.Stable
+public interface PulsarAdmin extends Closeable {
+
+    /**
+     * Get a new builder instance that can used to configure and build a {@link PulsarAdmin} instance.
+     *
+     * @return the {@link PulsarAdminBuilder}
+     *
+     */
+    static PulsarAdminBuilder builder() {
+        return DefaultImplementation.newAdminClientBuilder();
+    }
+
+    /**
+     * @return the clusters management object
+     */
+    Clusters clusters();
+
+    /**
+     * @return the brokers management object
+     */
+    Brokers brokers();
+
+    /**
+     * @return the tenants management object
+     */
+    Tenants tenants();
+
+    /**
+     *
+     * @deprecated since 2.0. See {@link #tenants()}
+     */
+    @Deprecated
+    Properties properties();
+
+    /**
+     * @return the namespaces management object
+     */
+    Namespaces namespaces();
+
+    /**
+     * @return the topics management object
+     */
+    Topics topics();
+
+    /**
+     * @return the bookies management object
+     */
+    Bookies bookies();
+
+    /**
+     * @return the persistentTopics management object
+     * @deprecated Since 2.0. See {@link #topics()}
+     */
+    @Deprecated
+    NonPersistentTopics nonPersistentTopics();
+
+    /**
+     * @return the resource quota management object
+     */
+    ResourceQuotas resourceQuotas();
+
+    /**
+     * @return does a looks up for the broker serving the topic
+     */
+    Lookup lookups();
+
+    /**
+     *
+     * @return the functions management object
+     */
+    Functions functions();
+
+    /**
+     * @return the sources management object
+     * @deprecated in favor of {@link #sources()}
+     */
+    @Deprecated
+    Source source();
+
+    /**
+     * @return the sources management object
+     */
+    Sources sources();
+
+    /**
+     * @return the sinks management object
+     * @deprecated in favor of {@link #sinks}
+     */
+    @Deprecated
+    Sink sink();
+
+    /**
+     * @return the sinks management object
+     */
+    Sinks sinks();
+
+    /**
+     * @return the Worker stats
+     */
+    Worker worker();
+
+    /**
+     * @return the broker statics
+     */
+    BrokerStats brokerStats();
+
+    /**
+     * @return the proxy statics
+     */
+    ProxyStats proxyStats();
+
+    /**
+     * @return the service HTTP URL that is being used
+     */
+    String getServiceUrl();
+
+    /**
+     * @return the client Configuration Data that is being used
+     */
+    ClientConfigurationData getClientConfigData();
+
+    /**
+     * @return the schemas
+     */
+    Schemas schemas();
+
+    /**
+     * @return the packages management object
+     */
+    Packages packages();
+
+    /**
+     * Close the PulsarAdminClient and release all the resources.
+     *
+     */
+    @Override
+    void close();
+}

pulsar-client-admin-api/src/main/java/org/apache/pulsar/client/admin/package-info.java

@@ -0,0 +1,19 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.pulsar.client.admin;

pulsar-client-admin-api/src/main/java/org/apache/pulsar/client/admin/utils/DefaultImplementation.java

@@ -0,0 +1,36 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.pulsar.client.admin.utils;
+
+import lombok.experimental.UtilityClass;
+import org.apache.pulsar.client.admin.PulsarAdminBuilder;
+
+/**
+ * Helper class for class instantiations and it also contains methods to work with schemas.
+ */
+@SuppressWarnings("unchecked")
+@UtilityClass
+public class DefaultImplementation {
+    private static final Class<PulsarAdminBuilder> ADMIN_CLIENT_BUILDER_IMPL = ReflectionUtils.newClassInstance(
+            "org.apache.pulsar.client.admin.internal.PulsarAdminBuilderImpl");
+
+    public static PulsarAdminBuilder newAdminClientBuilder() {
+        return ReflectionUtils.catchExceptions(() -> ADMIN_CLIENT_BUILDER_IMPL.newInstance());
+    }
+}