feat: add JVM wide truststore configuration and tests

src/main/java/io/github/ktestify/config/KtestifyConfig.java

@@ -64,6 +64,7 @@ private KtestifyConfig(Config config) {
         this.schemaRegistry = new SchemaRegistryConfig(config.getConfig("ktestify.schema-registry"));
         this.framework = new FrameworkConfig(config.getConfig("ktestify.framework"));
         applyLogLevels(config);
+        applyJvmTruststore(config);
         log.info("KtestifyConfig loaded successfully");
         log.debug("Kafka bootstrap servers: {}", kafka.getBootstrapServers());
         log.debug("Schema Registry URL: {}", schemaRegistry.getUrl());
@@ -105,6 +106,44 @@ private static void applyLogLevels(Config config) {
                 lc.getString("confluent-level"));
     }
 
+    /**
+     * Applies the JVM-level truststore defined in {@code ktestify.jvm.truststore} HOCON section by setting the
+     * corresponding {@code javax.net.ssl.*} system properties. This truststore is shared by all plugins and underlying
+     * libraries that don't provide their own SSL configuration.
+     *
+     * <p>If {@code location} is blank, no system properties are set and the JVM's built-in cacerts are used.
+     *
+     * <p>Supported keys and their environment variable overrides:
+     *
+     * <ul>
+     *   <li>{@code location} / {@code KTESTIFY_JVM_TRUSTSTORE_LOCATION}
+     *   <li>{@code password} / {@code KTESTIFY_JVM_TRUSTSTORE_PASSWORD}
+     *   <li>{@code type} / {@code KTESTIFY_JVM_TRUSTSTORE_TYPE} — {@code JKS} or {@code PKCS12}
+     * </ul>
+     *
+     * @param config the resolved Config object containing {@code ktestify.jvm.truststore}
+     */
+    public static void applyJvmTruststore(Config config) {
+        String location = config.getString("ktestify.jvm.truststore.location");
+        if (location == null || location.isBlank()) {
+            log.debug("No JVM truststore location configured; keeping JVM default cacerts");
+            return;
+        }
+
+        System.setProperty("javax.net.ssl.trustStore", location);
+        System.setProperty("javax.net.ssl.trustStoreType", config.getString("ktestify.jvm.truststore.type"));
+
+        String password = config.getString("ktestify.jvm.truststore.password");
+        if (password != null && !password.isBlank()) {
+            System.setProperty("javax.net.ssl.trustStorePassword", password);
+        }
+
+        log.info(
+                "JVM truststore applied — location={} type={}",
+                location,
+                config.getString("ktestify.jvm.truststore.type"));
+    }
+
     /**
      * Loads the default configuration using the standard HOCON loading mechanism. Configuration is loaded from:
      *

src/main/resources/reference.conf

@@ -193,5 +193,25 @@ ktestify {
     confluent-level    = "WARN"
     confluent-level    = ${?KTESTIFY_CONFLUENT_LOG_LEVEL}
   }
-}
 
+  # JVM Configuration
+  # =================
+  # Settings applied to the JVM itself at KtestifyConfig load time.
+  jvm {
+    # Default JVM truststore (javax.net.ssl.trustStore system properties).
+    # Used by any HTTPS/TLS client that doesn't have its own SSL config,
+    # e.g. plain HTTP calls, OAuth endpoints, etc.
+    # Leave location blank to keep the JVM's built-in cacerts.
+    truststore {
+      location = ""
+      location = ${?KTESTIFY_JVM_TRUSTSTORE_LOCATION}
+
+      password = ""
+      password = ${?KTESTIFY_JVM_TRUSTSTORE_PASSWORD}
+
+      # JKS or PKCS12
+      type = "JKS"
+      type = ${?KTESTIFY_JVM_TRUSTSTORE_TYPE}
+    }
+  }
+}

src/test/java/io/github/ktestify/config/KtestifyConfigTest.java

@@ -693,4 +693,112 @@ void testFrameworkTimeoutHelpers() {
         assertEquals(100L, fw.getPollIntervalMillis());
         assertEquals(5000L, fw.getBufferTimeMillis());
     }
+
+    // ==========================================
+    // JVM TRUSTSTORE TESTS
+    // ==========================================
+
+    @Nested
+    @DisplayName("JVM Truststore")
+    class JvmTruststoreTests {
+
+        @BeforeEach
+        void cleanSslProperties() {
+            System.clearProperty("javax.net.ssl.trustStore");
+            System.clearProperty("javax.net.ssl.trustStoreType");
+            System.clearProperty("javax.net.ssl.trustStorePassword");
+        }
+
+        @AfterEach
+        void restoreSslProperties() {
+            System.clearProperty("javax.net.ssl.trustStore");
+            System.clearProperty("javax.net.ssl.trustStoreType");
+            System.clearProperty("javax.net.ssl.trustStorePassword");
+        }
+
+        @Test
+        @DisplayName("Should not set truststore properties when location is blank")
+        void shouldNotSetTruststoreWhenLocationBlank() {
+            Config customConfig = ConfigFactory.parseString("""
+                    ktestify {
+                      jvm {
+                        truststore {
+                          location = ""
+                          password = ""
+                          type = "JKS"
+                        }
+                      }
+                    }
+                    """);
+
+            KtestifyConfig.load(customConfig);
+
+            assertNull(System.getProperty("javax.net.ssl.trustStore"));
+            assertNull(System.getProperty("javax.net.ssl.trustStoreType"));
+            assertNull(System.getProperty("javax.net.ssl.trustStorePassword"));
+        }
+
+        @Test
+        @DisplayName("Should set truststore location and type when location is provided")
+        void shouldSetTruststoreWhenLocationProvided() {
+            Config customConfig = ConfigFactory.parseString("""
+                    ktestify {
+                      jvm {
+                        truststore {
+                          location = "/path/to/truststore.jks"
+                          password = ""
+                          type = "PKCS12"
+                        }
+                      }
+                    }
+                    """);
+
+            KtestifyConfig.load(customConfig);
+
+            assertEquals("/path/to/truststore.jks", System.getProperty("javax.net.ssl.trustStore"));
+            assertEquals("PKCS12", System.getProperty("javax.net.ssl.trustStoreType"));
+            assertNull(System.getProperty("javax.net.ssl.trustStorePassword"));
+        }
+
+        @Test
+        @DisplayName("Should set truststore password when provided")
+        void shouldSetTruststorePasswordWhenProvided() {
+            Config customConfig = ConfigFactory.parseString("""
+                    ktestify {
+                      jvm {
+                        truststore {
+                          location = "/path/to/truststore.jks"
+                          password = "secret"
+                          type = "JKS"
+                        }
+                      }
+                    }
+                    """);
+
+            KtestifyConfig.load(customConfig);
+
+            assertEquals("/path/to/truststore.jks", System.getProperty("javax.net.ssl.trustStore"));
+            assertEquals("JKS", System.getProperty("javax.net.ssl.trustStoreType"));
+            assertEquals("secret", System.getProperty("javax.net.ssl.trustStorePassword"));
+        }
+
+        @Test
+        @DisplayName("Should default truststore type to JKS from reference.conf")
+        void shouldDefaultTruststoreTypeToJks() {
+            Config customConfig = ConfigFactory.parseString("""
+                    ktestify {
+                      jvm {
+                        truststore {
+                          location = "/path/to/truststore.jks"
+                        }
+                      }
+                    }
+                    """);
+
+            KtestifyConfig.load(customConfig);
+
+            assertEquals("/path/to/truststore.jks", System.getProperty("javax.net.ssl.trustStore"));
+            assertEquals("JKS", System.getProperty("javax.net.ssl.trustStoreType"));
+        }
+    }
 }