Merge pull request #195 from fnproject/logFrame

Adding env vars to be logged before each invocation

Author: nishalad95

runtime/src/main/java/com/fnproject/fn/runtime/MethodFunctionInvoker.java

@@ -17,6 +17,26 @@
  */
 public class MethodFunctionInvoker implements FunctionInvoker {
 
+    /*
+    * If enabled, print the logging framing content
+    */
+    public void logFramer(FunctionRuntimeContext rctx, InputEvent evt) {
+        String framer = rctx.getConfigurationByKey("FN_LOGFRAME_NAME").orElse("");
+
+        if (framer != "") {
+            String valueSrc = rctx.getConfigurationByKey("FN_LOGFRAME_HDR").orElse("");
+
+            if (valueSrc != "") {
+                String id = evt.getHeaders().get(valueSrc).orElse("");
+                if (id != "") {
+                    System.out.println(framer + "=" + id);
+                    System.err.println(framer + "=" + id);
+                }
+            }
+        }
+    }
+
+
     /**
      * Invoke the function wrapped by this loader
      *
@@ -33,6 +53,8 @@ public Optional<OutputEvent> tryInvoke(InvocationContext ctx, InputEvent evt) th
 
         Object rawResult;
 
+        logFramer(runtimeContext, evt);
+
         try {
             rawResult = method.getTargetMethod().invoke(ctx.getRuntimeContext().getInvokeInstance().orElse(null), userFunctionParams);
         } catch (IllegalAccessException | InvocationTargetException e) {

runtime/src/test/java/com/fnproject/fn/runtime/EndToEndInvokeTest.java

@@ -211,6 +211,19 @@ public void shouldReadBytesOnDefaultCodec() throws Exception {
 
     }
 
+    @Test
+    public void shouldPrintLogFrame() throws Exception {
+        fn.setConfig("FN_LOGFRAME_NAME", "containerID");
+        fn.setConfig("FN_LOGFRAME_HDR", "fnID");
+        fn.givenEvent().withHeader("fnID", "fnIDVal").withBody( "Hello world!").enqueue();
+
+        fn.thenRun(TestFn.class, "fnEcho");
+        assertThat(fn.getOnlyOutputAsString()).isEqualTo("Hello world!");
+        // stdout gets redirected to stderr - hence printing out twice
+        assertThat(fn.getStdErrAsString()).isEqualTo("containerID=fnIDVal\ncontainerID=fnIDVal\n");
+
+    }
+
 
     @Test
     public void shouldWriteBytesOnDefaultCodec() throws Exception {