feat: Use reference config for ssl context (#110)

* feat: Use reference config for ssl context

* comments

Author: hanny24

ssl-config/src/main/scala/com/avast/sst/ssl/SslContextModule.scala

@@ -1,7 +1,7 @@
 package com.avast.sst.ssl
 
 import cats.effect.Sync
-import com.typesafe.config.Config
+import com.typesafe.config.{Config, ConfigFactory}
 import com.typesafe.sslconfig.ssl.{
   ConfigSSLContextBuilder,
   DefaultKeyManagerFactoryWrapper,
@@ -14,13 +14,19 @@ import scala.language.higherKinds
 
 object SslContextModule {
 
-  /** Initializes [[javax.net.ssl.SSLContext]] from the provided config. */
-  def make[F[_]: Sync](config: Config): F[SSLContext] = Sync[F].delay {
+  /**
+    * Initializes [[javax.net.ssl.SSLContext]] from the provided config.
+    * @param withReference Whether we should use reference config of "ssl-config" library as well.
+    */
+  def make[F[_]: Sync](config: Config, withReference: Boolean = true): F[SSLContext] = Sync[F].delay {
     val loggerFactory = Slf4jLogger.factory
+    val finalConfig = if (withReference) config.withFallback(referenceConfigUnsafe()) else config
     new ConfigSSLContextBuilder(loggerFactory,
-                                SSLConfigFactory.parse(config, loggerFactory),
+                                SSLConfigFactory.parse(finalConfig, loggerFactory),
                                 new DefaultKeyManagerFactoryWrapper(KeyManagerFactory.getDefaultAlgorithm),
                                 new DefaultTrustManagerFactoryWrapper(TrustManagerFactory.getDefaultAlgorithm)).build
   }
 
+  private def referenceConfigUnsafe(): Config = ConfigFactory.defaultReference().getConfig("ssl-config")
+
 }

ssl-config/src/test/scala/com/avast/sst/ssl/SslContextModuleTest.scala

@@ -6,9 +6,19 @@ import org.scalatest.funsuite.AnyFunSuite
 
 class SslContextModuleTest extends AnyFunSuite {
 
-  test("SslContextModule initializes properly from JKS store") {
-    val sslContext = SslContextModule.make[SyncIO](ConfigFactory.load().getConfig("ssl-config")).unsafeRunSync()
+  test("SslContextModule initializes properly from JKS store with reference config") {
+    val sslContext = SslContextModule.make[SyncIO](ConfigFactory.empty()).unsafeRunSync()
     assert(sslContext.getProtocol === "TLSv1.2")
   }
 
+  test("SslContextModule initializes properly from JKS store with provided config") {
+    val sslContext = SslContextModule.make[SyncIO](ConfigFactory.load().getConfig("ssl-config"), withReference = false).unsafeRunSync()
+    assert(sslContext.getProtocol === "TLSv1.2")
+  }
+
+  test("SslContextModule fails to initialize for empty config and no reference config") {
+    val result = SslContextModule.make[SyncIO](ConfigFactory.empty(), withReference = false).attempt.unsafeRunSync()
+    assert(result.isLeft)
+  }
+
 }