Fixed handling of malformed resource spec (#27)

* Fixed handling of malformed resource spec

Added logging to emit certain failures and basic generation flow.
No longer hard failing on malformed specification files.

Author: rjlohan

pom.xml

@@ -18,6 +18,13 @@
   </properties>
 
   <dependencies>
+    <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
+    <dependency>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-core</artifactId>
+      <version>2.11.2</version>
+    </dependency>
+
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>

src/main/java/aws/cfn/codegen/json/Codegen.java

@@ -10,6 +10,8 @@
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.github.mustachejava.DefaultMustacheFactory;
 import com.github.mustachejava.Mustache;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.LogManager;
 
 import java.io.File;
 import java.io.FileOutputStream;
@@ -32,6 +34,8 @@
 
 public final class Codegen {
 
+    private static Logger logger = LogManager.getLogger(Codegen.class);
+
     private final ObjectMapper mapper;
     private final ObjectNode definitions;
     private final Config config;
@@ -189,6 +193,7 @@ public void generate() throws Exception {
         config.getSettings().getRegions().stream()
             .map(region -> {
                 try {
+                    logger.debug("Loading specification for {}", region);
                     return new Object[] {
                         region,
                         loadSpecification(region),
@@ -197,17 +202,21 @@ public void generate() throws Exception {
                     };
                 }
                 catch (Exception e) {
+                    logger.fatal(String.format("Loading specification for %s failed", region), e);
                     throw new RuntimeException(e);
                 }
             })
             .forEach(result -> {
+                String region = (String)result[0];
+                logger.debug("Starting generation for {} specification", region);
                 CfnSpecification spec = (CfnSpecification) result[1];
                 Map<String, File> locations = (Map<String, File>) result[2];
                 Map<String, ObjectNode> defns = (Map<String, ObjectNode>) result[3];
                 try {
                     generate(spec, locations, defns);
                 }
                 catch (Exception e) {
+                    logger.fatal(String.format("Generation for %s specification failed", region), e);
                     throw new RuntimeException(e);
                 }
             });
@@ -227,12 +236,26 @@ private void generate(CfnSpecification specification,
 
         Map<List<String>, ObjectNode> definitions = new LinkedHashMap<>(sorted.size());
         for (final String name: sorted) {
-            ResourceType type = resources.get(name);
-            String defnName = name.replace("::", "_");
-            resDefns.add(defnName);
-            ObjectNode typeDefn = mapper.createObjectNode();
-            handleType(typeDefn, defnName, name, type, true, propertyNames);
-            definitions.put(Arrays.asList(name, defnName), typeDefn);
+            ResourceType type = null;
+            try {
+                type = resources.get(name);
+                String defnName = name.replace("::", "_");
+                resDefns.add(defnName);
+                ObjectNode typeDefn = mapper.createObjectNode();
+                handleType(typeDefn, defnName, name, type, true, propertyNames);
+                definitions.put(Arrays.asList(name, defnName), typeDefn);
+                logger.debug("Processed type {}", name);
+            }
+            catch (Exception e)
+            {
+                // ignore and emit warning for malformed types in the spec
+                if (type != null) {
+                    logger.error("An error occurred processing type {}", name);
+                }
+                else {
+                    throw e;
+                }
+            }
         }
         addToPerGroupRoots(definitions, groupSpecDefinitions);