NIFIREG-242 Two-way synchronization of git repository backed flows

.gitattributes

@@ -0,0 +1,9 @@
+# Set the default behavior, in case people don't have core.autocrlf set.
+* text=auto
+
+# Explicitly declare text files you want to always be normalized and converted
+# to native line endings on checkout.
+*.sh text eol=lf
+*.py text eol=lf
+*.yml text eol=lf
+*.conf text eol=lf

.gitignore

@@ -13,5 +13,4 @@ nb-configuration.xml
 *.iml
 *.iws
 *~
-
 /bin/

nifi-registry-core/nifi-registry-data-model/src/main/java/org/apache/nifi/registry/sync/RepositorySyncStatus.java

@@ -0,0 +1,63 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.registry.sync;
+
+import io.swagger.annotations.ApiModel;
+import io.swagger.annotations.ApiModelProperty;
+
+import javax.xml.bind.annotation.XmlRootElement;
+import java.util.Collection;
+
+@XmlRootElement
+@ApiModel(value = "RepositorySyncStatus")
+public class RepositorySyncStatus {
+    private boolean isClean;
+    private boolean hasChanges;
+    private Collection<String> changes;
+
+    public RepositorySyncStatus(boolean isClean, boolean hasChanges, Collection<String> changes) {
+        this.isClean = isClean;
+        this.hasChanges = hasChanges;
+        this.changes = changes;
+    }
+
+    public RepositorySyncStatus(){}
+
+    @ApiModelProperty(value = "Repository is in sync with registry.", required = true)
+    public boolean getIsClean() {
+        return isClean;
+    }
+    public void setIsClean(boolean isClean) {
+        this.isClean = isClean;
+    }
+
+    @ApiModelProperty(value = "The repository contains changes not reflected in registry.", required = true)
+    public boolean getHasChanges() {
+        return this.hasChanges;
+    }
+    public void setHasChanges(boolean hasChanges) {
+        this.hasChanges = hasChanges;
+    }
+
+    @ApiModelProperty(value = "List of changes in the repository which should be synchronized with registry.", required = true)
+    public Collection<String> getChanges() {
+        return this.changes;
+    }
+    public void setChanges(Collection<String> changes) {
+        this.changes = changes;
+    }
+}

nifi-registry-core/nifi-registry-framework/src/main/java/org/apache/nifi/registry/provider/flow/FileSystemFlowPersistenceProvider.java

@@ -23,6 +23,7 @@
 import org.apache.nifi.registry.flow.FlowSnapshotContext;
 import org.apache.nifi.registry.provider.ProviderConfigurationContext;
 import org.apache.nifi.registry.provider.ProviderCreationException;
+import org.apache.nifi.registry.provider.sync.RepositorySyncStatus;
 import org.apache.nifi.registry.util.FileUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -183,4 +184,23 @@ protected File getSnapshotFile(final String bucketId, final String flowId, final
         return new File(flowStorageDir, snapshotFilename);
     }
 
+    @Override
+    public Boolean canBeSynchronized() {
+        return false;
+    }
+
+    @Override
+    public void getLatestChangesOfRemoteRepository() {
+
+    }
+
+    @Override
+    public void resetRepository() {
+
+    }
+
+    @Override
+    public RepositorySyncStatus getStatus() {
+        return RepositorySyncStatus.SuccessfulSynchronizedRepository();
+    }
 }

nifi-registry-core/nifi-registry-framework/src/main/java/org/apache/nifi/registry/provider/flow/git/Flow.java

@@ -16,6 +16,8 @@
  */
 package org.apache.nifi.registry.provider.flow.git;
 
+import org.apache.nifi.registry.util.FileUtils;
+
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
@@ -39,10 +41,14 @@ public boolean hasVersion(int version) {
         return versions.containsKey(version);
     }
 
-    public FlowPointer getFlowVersion(int version) {
+    public FlowPointer getFlowVersion(int version){
         return versions.get(version);
     }
 
+    public String getFlowId(){
+        return this.flowId;
+    }
+
     public void putVersion(int version, FlowPointer pointer) {
         versions.put(version, pointer);
     }
@@ -65,7 +71,7 @@ public static class FlowPointer {
 
         /**
          * Create new FlowPointer instance.
-         * @param fileName The filename must be sanitized, use {@link org.apache.nifi.registry.util.FileUtils#sanitizeFilename(String)} to do so.
+         * @param fileName The filename must be sanitized, use {@link FileUtils#sanitizeFilename(String)} to do so.
          */
         public FlowPointer(String fileName) {
             this.fileName = fileName;