Add additional metrics for user/client/session count (#31)

src/test/java/io/kokuwa/keycloak/metrics/KeycloakIT.java

@@ -1,11 +1,14 @@
 package io.kokuwa.keycloak.metrics;
 
 import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import java.time.Instant;
 import java.util.UUID;
+import java.util.function.Supplier;
 
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -73,4 +76,41 @@ public class KeycloakIT {
 				() -> assertEquals(loginErrorBefore1 + 0, loginErrorAfter1, "login failure #1"),
 				() -> assertEquals(loginErrorBefore2 + 1, loginErrorAfter2, "login failure #2"));
 	}
+
+	@DisplayName("user count")
+	@Test
+	void userCount(KeycloakClient keycloak, Prometheus prometheus) {
+
+		var realmName1 = "userCount_1";
+		var realmName2 = "userCount_2";
+		var username = UUID.randomUUID().toString();
+
+		keycloak.createRealm(realmName1);
+		keycloak.createRealm(realmName2);
+
+		await(() -> prometheus.userCount(realmName1) == 0, prometheus, "realm 1 not found");
+		await(() -> prometheus.userCount(realmName2) == 0, prometheus, "realm 2 not found");
+
+		keycloak.createUser(realmName1, username, UUID.randomUUID().toString());
+		keycloak.createUser(realmName1, UUID.randomUUID().toString(), UUID.randomUUID().toString());
+		keycloak.createUser(realmName1, UUID.randomUUID().toString(), UUID.randomUUID().toString());
+		keycloak.createUser(realmName2, UUID.randomUUID().toString(), UUID.randomUUID().toString());
+
+		await(() -> prometheus.userCount(realmName1) == 3, prometheus, "realm 1 shoud have 3 users");
+		await(() -> prometheus.userCount(realmName2) == 1, prometheus, "realm 2 shoud have 1 users");
+
+		keycloak.deleteUser(realmName1, username);
+
+		await(() -> prometheus.userCount(realmName1) == 2, prometheus, "realm 1 shoud have 2 users after deletion");
+		await(() -> prometheus.userCount(realmName2) == 1, prometheus, "realm 2 shoud have 1 users");
+	}
+
+	void await(Supplier<Boolean> check, Prometheus prometheus, String message) {
+		var end = Instant.now().plusSeconds(10);
+		while (Instant.now().isBefore(end) && !check.get()) {
+			assertDoesNotThrow(() -> Thread.sleep(1000));
+			prometheus.scrap();
+		}
+		assertTrue(check.get(), message);
+	}
 }

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

@@ -1,5 +1,7 @@
 package io.kokuwa.keycloak.metrics.junit;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
@@ -45,7 +47,8 @@ public class KeycloakClient {
 		client.setClientId(clientId);
 		client.setPublicClient(true);
 		client.setDirectAccessGrantsEnabled(true);
-		keycloak.realms().realm(realmName).clients().create(client);
+		var response = keycloak.realms().realm(realmName).clients().create(client);
+		assertEquals(201, response.getStatus());
 	}
 
 	public void createUser(String realmName, String username, String password) {
@@ -59,7 +62,15 @@ public class KeycloakClient {
 		user.setEmailVerified(true);
 		user.setUsername(username);
 		user.setCredentials(List.of(credential));
-		keycloak.realms().realm(realmName).users().create(user);
+		var response = keycloak.realms().realm(realmName).users().create(user);
+		assertEquals(201, response.getStatus());
+	}
+
+	public void deleteUser(String realmName, String username) {
+		keycloak.realms().realm(realmName).users()
+				.searchByUsername(username, true).stream()
+				.map(UserRepresentation::getId)
+				.forEach(keycloak.realms().realm(realmName).users()::delete);
 	}
 
 	public boolean login(String clientId, String realmName, String username, String password) {

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

@@ -55,8 +55,11 @@ public class KeycloakExtension implements BeforeAllCallback, ParameterResolver {
 				.withEnv("KEYCLOAK_ADMIN", "admin")
 				.withEnv("KEYCLOAK_ADMIN_PASSWORD", "password")
 				.withEnv("KC_LOG_CONSOLE_COLOR", "true")
+				.withEnv("KC_LOG_LEVEL", "io.kokuwa:trace")
 				.withEnv("KC_HEALTH_ENABLED", "true")
 				.withEnv("KC_METRICS_ENABLED", "true")
+				.withEnv("KC_METRICS_STATS_ENABLED", "true")
+				.withEnv("KC_METRICS_STATS_INTERVAL", "PT1s")
 				.withCopyFileToContainer(MountableFile.forHostPath(jar), "/opt/keycloak/providers/metrics.jar")
 				.withLogConsumer(out -> System.out.print(out.getUtf8String()))
 				.withExposedPorts(8080)

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

@@ -41,6 +41,14 @@ public class Prometheus {
 				.sum();
 	}
 
+	public int userCount(String realm) {
+		return state.stream()
+				.filter(metric -> Objects.equals(metric.name(), "keycloak_users"))
+				.filter(metric -> Objects.equals(metric.tags().get("realm"), realm))
+				.mapToInt(metric -> metric.value().intValue())
+				.sum();
+	}
+
 	public void scrap() {
 		state.clear();
 		Stream.of(client.scrap().split("[\\r\\n]+"))