feat(corda): prometheus exporter metrics integration

        Primary Change
        ---
        1. The corda ledger connector plugin now includes the prometheus metrics exporter integration
        2. OpenAPI spec now has api endpoint for getting the prometheus metrics

        Refactorings that were also necessary to incorporate 1) and 2)
        ------
        3. GetPrometheusMetricsV1 class is created to handle the corresponding api endpoint
        4. IPluginLedgerConnectorCordaOptions interface in PluginLedgerConnectorCorda class now has a prometheusExporter object optional field
        5. The PluginLedgerConnectorCorda class has relevant functions to incorporate prometheus exporter
        6. Updated Readme.md about the prometheus exporter
        7. Updated the test case located at packages/cactus-plugin-ledger-connector-corda/src/test/typescript/integration/deploy-cordapp-jars-to-nodes.test.ts
        8. Updated the OpenAPI spec file to have run-transaction endpoint which currently returns NOT_IMPLEMENTED with 501 code.

Resolve #535

Signed-off-by: Jagpreet Singh Sasan <jagpreet.singh.sasan@accenture.com>

packages/cactus-plugin-ledger-connector-corda/README.md

@@ -2,6 +2,41 @@
 
 > TODO: description
 
+### Usage Prometheus
+The prometheus exporter object is initialized in the `PluginLedgerConnectorCorda` class constructor itself, so instantiating the object of the `PluginLedgerConnectorCorda` class, gives access to the exporter object.
+You can also initialize the prometheus exporter object seperately and then pass it to the `IPluginLedgerConnectorCordaOptions` interface for `PluginLedgerConnectoCorda` constructor.
+
+`getPrometheusExporterMetricsEndpointV1` function returns the prometheus exporter metrics, currently displaying the total transaction count, which currently increments everytime the `transact()` method of the `PluginLedgerConnectorCorda` class is called.
+
+### Prometheus Integration
+To use Prometheus with this exporter make sure to install [Prometheus main component](https://prometheus.io/download/).
+Once Prometheus is setup, the corresponding scrape_config needs to be added to the prometheus.yml
+
+```(yaml)
+- job_name: 'corda_ledger_connector_exporter'
+  metrics_path: api/v1/plugins/@hyperledger/cactus-plugin-ledger-connector-corda/get-prometheus-exporter-metrics
+  scrape_interval: 5s
+  static_configs:
+    - targets: ['{host}:{port}']
+```
+
+Here the `host:port` is where the prometheus exporter metrics are exposed. The test cases (For example, packages/cactus-plugin-ledger-connector-corda/src/test/typescript/integration/deploy-cordapp-jars-to-nodes.test.ts) exposes it over `0.0.0.0` and a random port(). The random port can be found in the running logs of the test case and looks like (42379 in the below mentioned URL)
+`Metrics URL: http://0.0.0.0:42379/api/v1/plugins/@hyperledger/cactus-plugin-ledger-connector-corda/get-prometheus-exporter-metrics`
+
+Once edited, you can start the prometheus service by referencing the above edited prometheus.yml file.
+On the prometheus graphical interface (defaulted to http://localhost:9090), choose **Graph** from the menu bar, then select the **Console** tab. From the **Insert metric at cursor** drop down, select **cactus_corda_total_tx_count** and click **execute**
+
+### Helper code
+
+###### response.type.ts
+This file contains the various responses of the metrics.
+
+###### data-fetcher.ts
+This file contains functions encasing the logic to process the data points
+
+###### metrics.ts
+This file lists all the prometheus metrics and what they are used for.
+
 ## Usage
 
 Take a look at how the API client can be used to run transactions on a corda ledger:

packages/cactus-plugin-ledger-connector-corda/package.json

@@ -89,6 +89,7 @@
     "@hyperledger/cactus-core-api": "0.4.1",
     "axios": "0.21.1",
     "express-openapi-validator": "4.10.5",
+    "prom-client": "13.0.0",
     "internal-ip": "6.2.0",
     "joi": "14.3.1",
     "node-ssh": "11.1.0",

packages/cactus-plugin-ledger-connector-corda/src/main-server/kotlin/gen/kotlin-spring/src/main/kotlin/org/hyperledger/cactus/plugin/ledger/connector/corda/server/api/ApiPluginLedgerConnectorCorda.kt

@@ -59,6 +59,15 @@ class ApiPluginLedgerConnectorCordaController(@Autowired(required = true) val se
     }
 
 
+    @GetMapping(
+        value = ["/api/v1/plugins/@hyperledger/cactus-plugin-ledger-connector-corda/get-prometheus-exporter-metrics"],
+        produces = ["text/plain"]
+    )
+    fun getPrometheusExporterMetricsV1(): ResponseEntity<kotlin.String> {
+        return ResponseEntity(service.getPrometheusExporterMetricsV1(), HttpStatus.valueOf(200))
+    }
+
+
     @PostMapping(
         value = ["/api/v1/plugins/@hyperledger/cactus-plugin-ledger-connector-corda/invoke-contract"],
         produces = ["application/json"],

packages/cactus-plugin-ledger-connector-corda/src/main-server/kotlin/gen/kotlin-spring/src/main/kotlin/org/hyperledger/cactus/plugin/ledger/connector/corda/server/api/ApiPluginLedgerConnectorCordaService.kt

@@ -16,6 +16,8 @@ interface ApiPluginLedgerConnectorCordaService {
 
 	fun diagnoseNodeV1(diagnoseNodeV1Request: DiagnoseNodeV1Request?): DiagnoseNodeV1Response
 
+	fun getPrometheusExporterMetricsV1(): kotlin.String
+
 	fun invokeContractV1(invokeContractV1Request: InvokeContractV1Request?): InvokeContractV1Response
 
 	fun listFlowsV1(listFlowsV1Request: ListFlowsV1Request?): ListFlowsV1Response

packages/cactus-plugin-ledger-connector-corda/src/main/json/openapi.json

@@ -721,6 +721,10 @@
                         "$ref": "#/components/schemas/NodeDiagnosticInfo"
                     }
                 }
+            },
+            "PrometheusExporterMetricsResponse": {
+                "type": "string",
+                "nullable": false
             }
         }
     },
@@ -904,6 +908,31 @@
                     }
                 }
             }
+        },
+        "/api/v1/plugins/@hyperledger/cactus-plugin-ledger-connector-corda/get-prometheus-exporter-metrics": {
+            "get": {
+                "x-hyperledger-cactus": {
+                    "http": {
+                        "verbLowerCase": "get",
+                        "path": "/api/v1/plugins/@hyperledger/cactus-plugin-ledger-connector-corda/get-prometheus-exporter-metrics"
+                    }
+                },
+                "operationId": "getPrometheusExporterMetricsV1",
+                "summary": "Get the Prometheus Metrics",
+                "parameters": [],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "content": {
+                            "text/plain": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/PrometheusExporterMetricsResponse"
+                                }
+                            }
+                        }
+                    }
+                }
+            }
         }
     }
 }

packages/cactus-plugin-ledger-connector-corda/src/main/typescript/generated/openapi/typescript-axios/api.ts

@@ -765,6 +765,42 @@ export const DefaultApiAxiosParamCreator = function (configuration?: Configurati
                 options: localVarRequestOptions,
             };
         },
+        /**
+         * 
+         * @summary Get the Prometheus Metrics
+         * @param {*} [options] Override http request option.
+         * @throws {RequiredError}
+         */
+        getPrometheusExporterMetricsV1: async (options: any = {}): Promise<RequestArgs> => {
+            const localVarPath = `/api/v1/plugins/@hyperledger/cactus-plugin-ledger-connector-corda/get-prometheus-exporter-metrics`;
+            // use dummy base URL string because the URL constructor only accepts absolute URLs.
+            const localVarUrlObj = new URL(localVarPath, 'https://example.com');
+            let baseOptions;
+            if (configuration) {
+                baseOptions = configuration.baseOptions;
+            }
+            const localVarRequestOptions = { method: 'GET', ...baseOptions, ...options};
+            const localVarHeaderParameter = {} as any;
+            const localVarQueryParameter = {} as any;
+
+
+
+            const query = new URLSearchParams(localVarUrlObj.search);
+            for (const key in localVarQueryParameter) {
+                query.set(key, localVarQueryParameter[key]);
+            }
+            for (const key in options.query) {
+                query.set(key, options.query[key]);
+            }
+            localVarUrlObj.search = (new URLSearchParams(query)).toString();
+            let headersFromBaseOptions = baseOptions && baseOptions.headers ? baseOptions.headers : {};
+            localVarRequestOptions.headers = {...localVarHeaderParameter, ...headersFromBaseOptions, ...options.headers};
+
+            return {
+                url: localVarUrlObj.pathname + localVarUrlObj.search + localVarUrlObj.hash,
+                options: localVarRequestOptions,
+            };
+        },
         /**
          * 
          * @summary Invokes a contract on a Corda ledger (e.g. a flow)
@@ -922,6 +958,19 @@ export const DefaultApiFp = function(configuration?: Configuration) {
                 return axios.request(axiosRequestArgs);
             };
         },
+        /**
+         * 
+         * @summary Get the Prometheus Metrics
+         * @param {*} [options] Override http request option.
+         * @throws {RequiredError}
+         */
+        async getPrometheusExporterMetricsV1(options?: any): Promise<(axios?: AxiosInstance, basePath?: string) => AxiosPromise<string>> {
+            const localVarAxiosArgs = await DefaultApiAxiosParamCreator(configuration).getPrometheusExporterMetricsV1(options);
+            return (axios: AxiosInstance = globalAxios, basePath: string = BASE_PATH) => {
+                const axiosRequestArgs = {...localVarAxiosArgs.options, url: basePath + localVarAxiosArgs.url};
+                return axios.request(axiosRequestArgs);
+            };
+        },
         /**
          * 
          * @summary Invokes a contract on a Corda ledger (e.g. a flow)
@@ -990,6 +1039,15 @@ export const DefaultApiFactory = function (configuration?: Configuration, basePa
         diagnoseNodeV1(diagnoseNodeV1Request?: DiagnoseNodeV1Request, options?: any): AxiosPromise<DiagnoseNodeV1Response> {
             return DefaultApiFp(configuration).diagnoseNodeV1(diagnoseNodeV1Request, options).then((request) => request(axios, basePath));
         },
+        /**
+         * 
+         * @summary Get the Prometheus Metrics
+         * @param {*} [options] Override http request option.
+         * @throws {RequiredError}
+         */
+        getPrometheusExporterMetricsV1(options?: any): AxiosPromise<string> {
+            return DefaultApiFp(configuration).getPrometheusExporterMetricsV1(options).then((request) => request(axios, basePath));
+        },
         /**
          * 
          * @summary Invokes a contract on a Corda ledger (e.g. a flow)
@@ -1051,6 +1109,17 @@ export class DefaultApi extends BaseAPI {
         return DefaultApiFp(this.configuration).diagnoseNodeV1(diagnoseNodeV1Request, options).then((request) => request(this.axios, this.basePath));
     }
 
+    /**
+     * 
+     * @summary Get the Prometheus Metrics
+     * @param {*} [options] Override http request option.
+     * @throws {RequiredError}
+     * @memberof DefaultApi
+     */
+    public getPrometheusExporterMetricsV1(options?: any) {
+        return DefaultApiFp(this.configuration).getPrometheusExporterMetricsV1(options).then((request) => request(this.axios, this.basePath));
+    }
+
     /**
      * 
      * @summary Invokes a contract on a Corda ledger (e.g. a flow)

packages/cactus-plugin-ledger-connector-corda/src/main/typescript/plugin-ledger-connector-corda.ts

@@ -23,11 +23,23 @@ import {
 
 import { DeployContractJarsEndpoint } from "./web-services/deploy-contract-jars-endpoint";
 
+import {
+  IGetPrometheusExporterMetricsEndpointV1Options,
+  GetPrometheusExporterMetricsEndpointV1,
+} from "./web-services/get-prometheus-exporter-metrics-endpoint-v1";
+
+import { PrometheusExporter } from "./prometheus-exporter/prometheus-exporter";
+import {
+  IInvokeContractEndpointV1Options,
+  InvokeContractEndpointV1,
+} from "./web-services/invoke-contract-endpoint-v1";
+
 export interface IPluginLedgerConnectorCordaOptions
   extends ICactusPluginOptions {
   logLevel?: LogLevelDesc;
   sshConfigAdminShell: SshConfig;
   corDappsDir: string;
+  prometheusExporter?: PrometheusExporter;
   cordaStartCmd?: string;
   cordaStopCmd?: string;
 }
@@ -38,6 +50,7 @@ export class PluginLedgerConnectorCorda
 
   private readonly instanceId: string;
   private readonly log: Logger;
+  public prometheusExporter: PrometheusExporter;
 
   private endpoints: IWebServiceEndpoint[] | undefined;
 
@@ -58,6 +71,23 @@ export class PluginLedgerConnectorCorda
     const label = "plugin-ledger-connector-corda";
     this.log = LoggerProvider.getOrCreate({ level, label });
     this.instanceId = this.options.instanceId;
+    this.prometheusExporter =
+      options.prometheusExporter ||
+      new PrometheusExporter({ pollingIntervalInMin: 1 });
+    Checks.truthy(
+      this.prometheusExporter,
+      `${fnTag} options.prometheusExporter`,
+    );
+  }
+
+  public getPrometheusExporter(): PrometheusExporter {
+    return this.prometheusExporter;
+  }
+
+  public async getPrometheusExporterMetrics(): Promise<string> {
+    const res: string = await this.prometheusExporter.getPrometheusMetrics();
+    this.log.debug(`getPrometheusExporterMetrics() response: %o`, res);
+    return res;
   }
 
   public async getConsensusAlgorithmFamily(): Promise<
@@ -83,7 +113,8 @@ export class PluginLedgerConnectorCorda
   }
 
   public async transact(): Promise<any> {
-    throw new Error("Method not implemented.");
+    this.prometheusExporter.addCurrentTransaction();
+    return null as any;
   }
 
   async registerWebServices(app: Express): Promise<IWebServiceEndpoint[]> {
@@ -111,6 +142,24 @@ export class PluginLedgerConnectorCorda
 
       endpoints.push(endpoint);
     }
+
+    {
+      const opts: IInvokeContractEndpointV1Options = {
+        connector: this,
+        logLevel: this.options.logLevel,
+      };
+      const endpoint = new InvokeContractEndpointV1(opts);
+      endpoints.push(endpoint);
+    }
+
+    {
+      const opts: IGetPrometheusExporterMetricsEndpointV1Options = {
+        connector: this,
+        logLevel: this.options.logLevel,
+      };
+      const endpoint = new GetPrometheusExporterMetricsEndpointV1(opts);
+      endpoints.push(endpoint);
+    }
     this.log.info(`Instantiated endpoints of ${pkgName}`);
     return endpoints;
   }

packages/cactus-plugin-ledger-connector-corda/src/main/typescript/prometheus-exporter/data-fetcher.ts

@@ -0,0 +1,7 @@
+import { Transactions } from "./response.type";
+
+import { totalTxCount, K_CACTUS_CORDA_TOTAL_TX_COUNT } from "./metrics";
+
+export async function collectMetrics(transactions: Transactions) {
+  totalTxCount.labels(K_CACTUS_CORDA_TOTAL_TX_COUNT).set(transactions.counter);
+}

packages/cactus-plugin-ledger-connector-corda/src/main/typescript/prometheus-exporter/metrics.ts

@@ -0,0 +1,9 @@
+import { Gauge } from "prom-client";
+
+export const K_CACTUS_CORDA_TOTAL_TX_COUNT = "cactus_corda_total_tx_count";
+
+export const totalTxCount = new Gauge({
+  name: K_CACTUS_CORDA_TOTAL_TX_COUNT,
+  help: "Total transactions executed",
+  labelNames: ["type"],
+});