First draft of implementation (#1)

* First draft of implementation

Readme will follow

* Rename id.

* Exclude `commons-io` to disable build warnings

* Simplify metrics and add documentation

src/test/java/io/kokuwa/keycloak/metrics/junit/KeycloakClient.java

@@ -0,0 +1,72 @@
+package io.kokuwa.keycloak.metrics.junit;
+
+import java.util.List;
+import java.util.Map;
+
+import javax.ws.rs.NotAuthorizedException;
+import javax.ws.rs.core.MultivaluedHashMap;
+
+import org.keycloak.OAuth2Constants;
+import org.keycloak.admin.client.Keycloak;
+import org.keycloak.admin.client.token.TokenService;
+import org.keycloak.representations.idm.ClientRepresentation;
+import org.keycloak.representations.idm.CredentialRepresentation;
+import org.keycloak.representations.idm.RealmRepresentation;
+import org.keycloak.representations.idm.UserRepresentation;
+
+/**
+ * Client for keycloak.
+ *
+ * @author Stephan Schnabel
+ */
+public class KeycloakClient {
+
+	private final Keycloak keycloak;
+	private final TokenService token;
+
+	KeycloakClient(Keycloak keycloak, TokenService token) {
+		this.keycloak = keycloak;
+		this.token = token;
+	}
+
+	public String createRealm(String realmName) {
+		var client = new ClientRepresentation();
+		client.setClientId("test");
+		client.setPublicClient(true);
+		client.setDirectAccessGrantsEnabled(true);
+		var realm = new RealmRepresentation();
+		realm.setEnabled(true);
+		realm.setRealm(realmName);
+		realm.setEventsListeners(List.of("metrics-listener"));
+		realm.setClients(List.of(client));
+		keycloak.realms().create(realm);
+		return keycloak.realms().realm(realmName).toRepresentation().getId();
+	}
+
+	public void createUser(String realmName, String username, String password) {
+		var credential = new CredentialRepresentation();
+		credential.setType(CredentialRepresentation.PASSWORD);
+		credential.setValue(password);
+		credential.setTemporary(false);
+		var user = new UserRepresentation();
+		user.setEnabled(true);
+		user.setEmail(username + "@example.org");
+		user.setEmailVerified(true);
+		user.setUsername(username);
+		user.setCredentials(List.of(credential));
+		keycloak.realms().realm(realmName).users().create(user);
+	}
+
+	public boolean login(String realmName, String username, String password) {
+		try {
+			token.grantToken(realmName, new MultivaluedHashMap<>(Map.of(
+					OAuth2Constants.CLIENT_ID, "test",
+					OAuth2Constants.GRANT_TYPE, OAuth2Constants.PASSWORD,
+					OAuth2Constants.USERNAME, username,
+					OAuth2Constants.PASSWORD, password)));
+			return true;
+		} catch (NotAuthorizedException e) {
+			return false;
+		}
+	}
+}

src/test/java/io/kokuwa/keycloak/metrics/junit/KeycloakExtension.java

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+package io.kokuwa.keycloak.metrics.junit;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.IOException;
+import java.time.Duration;
+import java.util.Properties;
+import java.util.Set;
+
+import javax.ws.rs.client.ClientBuilder;
+
+import org.junit.jupiter.api.extension.BeforeAllCallback;
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.ParameterContext;
+import org.junit.jupiter.api.extension.ParameterResolver;
+import org.keycloak.admin.client.Keycloak;
+import org.keycloak.admin.client.token.TokenService;
+import org.testcontainers.containers.GenericContainer;
+import org.testcontainers.containers.wait.strategy.Wait;
+import org.testcontainers.utility.MountableFile;
+
+import io.kokuwa.keycloak.metrics.prometheus.Prometheus;
+import io.kokuwa.keycloak.metrics.prometheus.PrometheusClient;
+
+/**
+ * JUnit extension to start keycloak.
+ *
+ * @author Stephan Schnabel
+ */
+public class KeycloakExtension implements BeforeAllCallback, ParameterResolver {
+
+	private static KeycloakClient client;
+	private static Prometheus prometheus;
+
+	@Override
+	public void beforeAll(ExtensionContext context) throws Exception {
+
+		if (client != null) {
+			return;
+		}
+
+		// get test properties
+
+		var properties = new Properties();
+		try {
+			properties.load(getClass().getResourceAsStream("/test.properties"));
+		} catch (IOException e) {
+			throw new Exception("Failed to read properties", e);
+		}
+		var version = properties.getProperty("version");
+		var jar = properties.getProperty("jar");
+		var timeout = properties.getProperty("timeout");
+
+		// create and start container
+
+		@SuppressWarnings("resource")
+		var container = new GenericContainer<>("quay.io/keycloak/keycloak:" + version)
+				.withEnv("KEYCLOAK_ADMIN", "admin")
+				.withEnv("KEYCLOAK_ADMIN_PASSWORD", "password")
+				.withEnv("KC_LOG_CONSOLE_COLOR", "true")
+				.withEnv("KC_HEALTH_ENABLED", "true")
+				.withEnv("KC_METRICS_ENABLED", "true")
+				.withCopyFileToContainer(MountableFile.forHostPath(jar), "/opt/keycloak/providers/metrics.jar")
+				.withLogConsumer(out -> System.out.print(out.getUtf8String()))
+				.withExposedPorts(8080)
+				.withStartupTimeout(Duration.parse(timeout))
+				.waitingFor(Wait.forHttp("/health").forPort(8080))
+				.withCommand("start-dev");
+		try {
+			container.start();
+		} catch (RuntimeException e) {
+			throw new Exception("Failed to start keycloak", e);
+		}
+
+		// create client for keycloak container
+
+		var url = "http://" + container.getHost() + ":" + container.getMappedPort(8080);
+		var keycloak = Keycloak.getInstance(url, "master", "admin", "password", "admin-cli");
+		assertEquals(version, keycloak.serverInfo().getInfo().getSystemInfo().getVersion(), "version invalid");
+		var target = ClientBuilder.newClient().target(url);
+		var token = Keycloak.getClientProvider().targetProxy(target, TokenService.class);
+		prometheus = new Prometheus(Keycloak.getClientProvider().targetProxy(target, PrometheusClient.class));
+		client = new KeycloakClient(keycloak, token);
+	}
+
+	@Override
+	public boolean supportsParameter(ParameterContext parameterContext, ExtensionContext extensionContext) {
+		return Set.of(KeycloakClient.class, Prometheus.class).contains(parameterContext.getParameter().getType());
+	}
+
+	@Override
+	public Object resolveParameter(ParameterContext parameterContext, ExtensionContext extensionContext) {
+		return parameterContext.getParameter().getType().equals(KeycloakClient.class) ? client : prometheus;
+	}
+}