[[embedded-api]]
= Embedded API
:author:            James R. Perkins
:email:             jperkins@redhat.com
:idprefix:
:idseparator:       -

The embedded API can be used to launch {appservername} within a currently running process.

The embedded server can be reinitialized with a different JBoss Home. However the module directory, `module.path`
system property, and the modules system packages, `jboss.modules.system.pkgs` system property, are effectively static.
This means that creating a new embedded server or host controller within the same VM will not allow overriding the
modules directory or the system packages.

You can also set a hint to indicate which log manager is being used. The hint attempts to ensure that JBoss Logging
will bind to the correct log manager. It also adds the hinted logging package to the modules system packages.

IMPORTANT: If using the embedded API with Java 11 you'll need to add `--add-module=java.se` to your JVM arguments. See
https://issues.redhat.com/browse/MODULES-372[MODULES-372] for details.

== Standalone API

A standalone server allows you to manage the lifecycle of a server within the currently running process. The server
can be configured in admin-only mode or fully started and applications can be deployed.

=== Examples

.Simple Example
[source,java,options="nowrap"]
----
final StandaloneServer server = EmbeddedProcessFactory.createStandaloneServer(Configuration.Builder.of(jbossHome).build());
server.start();

try {
    // Print the listening address
    final ModelControllerClient client = server.getModelControllerClient();
    final ModelNode address = Operations.createAddress("interface", "public");
    final ModelNode op = Operations.createReadAttributeOperation(address, "inet-address");
    op.get("resolve-expressions").set(true);
    final ModelNode result = client.execute(op);
    if (!Operations.isSuccessfulOutcome((result))) {
        throw new RuntimeException("Failed to get the public inet-address: " + Operations.getFailureDescription(result));
    }
    System.out.printf("Listening on %s%n", Operations.readResult(result).asString());
} finally {
    server.stop();
}
----

.Server in admin-only Example
[source,java,options="nowrap"]
----
final StandaloneServer server = EmbeddedProcessFactory.createStandaloneServer(
    Configuration.Builder.of(jbossHome)
        .addCommandArgument("--admin-only")
        .build());
server.start();

try {
    // Print the listening address
    final ModelControllerClient client = server.getModelControllerClient();
    final ModelNode address = Operations.createAddress();
    final ModelNode op = Operations.createReadAttributeOperation(address, "running-mode");
    op.get("resolve-expressions").set(true);
    final ModelNode result = client.execute(op);
    if (!Operations.isSuccessfulOutcome((result))) {
        throw new RuntimeException("Failed to get the running-mode: " + Operations.getFailureDescription(result));
    }
    System.out.printf("Running mode is %s%n", Operations.readResult(result).asString());
} finally {
    server.stop();
}
----

.log4j2 Hint
[source,java,options="nowrap"]
----
final StandaloneServer server = EmbeddedProcessFactory.createStandaloneServer(Configuration.Builder.of(jbossHome)
        .setLoggerHint(Configuration.LoggerHint.LOG4J2)
        .build()
);
server.start();

try {
    // Print the listening address
    final ModelControllerClient client = server.getModelControllerClient();
    final ModelNode address = Operations.createAddress("interface", "public");
    final ModelNode op = Operations.createReadAttributeOperation(address, "inet-address");
    op.get("resolve-expressions").set(true);
    final ModelNode result = client.execute(op);
    if (!Operations.isSuccessfulOutcome((result))) {
        throw new RuntimeException("Failed to get the public inet-address: " + Operations.getFailureDescription(result));
    }
    org.apache.logging.log4j.LogManager.getFormatterLogger(Main.class).info("Listening on %s%n", Operations.readResult(result).asString());
} finally {
    server.stop();
}
----

== Host Controller API

The host controller API creates a host controller in the current process. The host controller is started in `admin-only`
mode therefore servers within the domain cannot be started. However the server configuration can be altered via
management operations.

=== Example

.Simple Example
[source,java,options="nowrap"]
----
final HostController server = EmbeddedProcessFactory.createHostController(Configuration.Builder.of(jbossHome).build());
server.start();

try {
    // Print the listening address
    final ModelControllerClient client = server.getModelControllerClient();
    final ModelNode address = new ModelNode().setEmptyList();
    final ModelNode op = Operations.createOperation(ClientConstants.READ_CHILDREN_NAMES_OPERATION, address);
    op.get(ClientConstants.CHILD_TYPE).set(ClientConstants.SERVER_GROUP);
    final ModelNode result = client.execute(op);
    if (!Operations.isSuccessfulOutcome(result)) {
        throw new RuntimeException("Failed to get the public inet-address: " + Operations.getFailureDescription(result));
    }
    System.out.println("Available server groups:");
    for (ModelNode value : Operations.readResult(result).asList()) {
        System.out.printf("\t%s%n", value.asString());
    }
} finally {
    server.stop();
}
----