[NC-1970] Added handling in admin_addPeer for when p2p is disabled (#655)

Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

ethereum/jsonrpc/src/main/java/tech/pegasys/pantheon/ethereum/jsonrpc/internal/methods/AdminAddPeer.java

@@ -19,6 +19,7 @@ import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcError;
 import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcErrorResponse;
 import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcResponse;
 import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcSuccessResponse;
+import tech.pegasys.pantheon.ethereum.p2p.P2pDisabledException;
 import tech.pegasys.pantheon.ethereum.p2p.api.P2PNetwork;
 import tech.pegasys.pantheon.ethereum.p2p.peers.DefaultPeer;
 import tech.pegasys.pantheon.ethereum.p2p.peers.Peer;
@@ -52,6 +53,8 @@ public class AdminAddPeer implements JsonRpcMethod {
       return new JsonRpcErrorResponse(req.getId(), JsonRpcError.INVALID_PARAMS);
     } catch (final IllegalArgumentException e) {
       return new JsonRpcErrorResponse(req.getId(), JsonRpcError.PARSE_ERROR);
+    } catch (final P2pDisabledException e) {
+      return new JsonRpcErrorResponse(req.getId(), JsonRpcError.P2P_DISABLED);
     } catch (final Exception e) {
       LOG.error("Error processing request: " + req, e);
       throw e;

ethereum/jsonrpc/src/test/java/tech/pegasys/pantheon/ethereum/jsonrpc/internal/methods/AdminAddPeerTest.java

@@ -22,6 +22,7 @@ import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcError;
 import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcErrorResponse;
 import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcResponse;
 import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcSuccessResponse;
+import tech.pegasys.pantheon.ethereum.p2p.P2pDisabledException;
 import tech.pegasys.pantheon.ethereum.p2p.api.P2PNetwork;
 
 import org.junit.Before;
@@ -113,4 +114,31 @@ public class AdminAddPeerTest {
 
     assertThat(actualResponse).isEqualToComparingFieldByField(expectedResponse);
   }
+
+  @Test
+  public void requestReturnsErrorWhenP2pDisabled() {
+    when(p2pNetwork.addMaintainConnectionPeer(any()))
+        .thenThrow(
+            new P2pDisabledException("P2P networking disabled.  Unable to connect to add peer."));
+
+    final JsonRpcRequest request =
+        new JsonRpcRequest(
+            "2.0",
+            "admin_addPeer",
+            new String[] {
+              "enode://"
+                  + "00000000000000000000000000000000"
+                  + "00000000000000000000000000000000"
+                  + "00000000000000000000000000000000"
+                  + "00000000000000000000000000000000"
+                  + "@127.0.0.1:30303"
+            });
+
+    final JsonRpcResponse expectedResponse =
+        new JsonRpcErrorResponse(request.getId(), JsonRpcError.P2P_DISABLED);
+
+    final JsonRpcResponse actualResponse = method.response(request);
+
+    assertThat(actualResponse).isEqualToComparingFieldByField(expectedResponse);
+  }
 }