chaincode metadata changes added

Signed-off-by: SunnyAjin <ajin847@gmail.com>

app/platform/fabric/Proxy.ts

@@ -597,4 +597,24 @@ export class Proxy {
 		}
 		return results;
 	}
+
+	/*
+	 * @param {*} contract_name
+	 * @returns
+	 * @memberof Proxy
+	 */
+	async getContractMetadata(network_id, contract_name) {
+		const client = this.platform.getClient(network_id);
+		const channel_name = Object.keys(client.fabricGateway.config.channels)[0];
+		let metadata;
+		try {
+			metadata = await client.fabricGateway.queryContractMetadata(channel_name, contract_name);
+		} catch (e) {
+			logger.debug('getContractMetadata >> ', e);
+		} if (metadata) {
+			return metadata;
+		}
+		logger.error('response_payloads is null');
+		return 'response_payloads is null';
+	}
 }

app/platform/fabric/gateway/FabricGateway.ts

@@ -523,4 +523,14 @@ export class FabricGateway {
 			return null;
 		}
 	}
+	async queryContractMetadata(channel_name, contract_name) {
+		const network = await this.gateway.getNetwork(channel_name);
+		// Get the contract from the network.        
+		const contract = network.getContract(contract_name);
+		// Get the contract metadata from the network.
+		const result = await contract.evaluateTransaction('org.hyperledger.fabric:GetMetadata');
+		const metadata = JSON.parse(result.toString('utf8'));
+		logger.debug('queryContractMetadata', metadata)
+		return metadata;
+	}
 }

app/rest/platformroutes.ts

@@ -254,6 +254,21 @@ export async function platformroutes(
 			}
 		});
 	});
-
+
+	/**
+	 * Return channel metadata
+	 * GET /metadata
+	 * curl -i 'http://<host>:<port>/metadata/<chaincode>'
+	 */
+	router.get('/metadata/:chaincode', (req, res) => {
+		const chaincode = req.params.chaincode;
+		if (chaincode) {
+			proxy.getContractMetadata(req.network, chaincode).then((data: any) => {
+				res.send({ status: 200, data: data });
+			});
+		} else {
+			return requtil.invalidRequest(req, res);
+		}
+	});
 
 } // End platformroutes()