Add redux actions/reducer for metrics

ui/src/actions/metricsActions.ts

@@ -0,0 +1,45 @@
+import { Dispatch } from "redux";
+import { getMetrics, MetricsResponse } from "../api";
+import { toErrorString, toErrorStringWithHttpStatus } from "../utils";
+
+// List of metrics related action types.
+export const GET_METRICS_BEGIN = "GET_METRICS_BEGIN";
+export const GET_METRICS_SUCCESS = "GET_METRICS_SUCCESS";
+export const GET_METRICS_ERROR = "GET_METRICS_ERROR";
+
+interface GetMetricsBeginAction {
+  type: typeof GET_METRICS_BEGIN;
+}
+
+interface GetMetricsSuccessAction {
+  type: typeof GET_METRICS_SUCCESS;
+  payload: MetricsResponse;
+}
+
+interface GetMetricsErrorAction {
+  type: typeof GET_METRICS_ERROR;
+  error: string;
+}
+
+// Union of all metrics related actions.
+export type MetricsActionTypes =
+  | GetMetricsBeginAction
+  | GetMetricsSuccessAction
+  | GetMetricsErrorAction;
+
+export function getMetricsAsync() {
+  return async (dispatch: Dispatch<MetricsActionTypes>) => {
+    dispatch({ type: GET_METRICS_BEGIN });
+    try {
+      const response = await getMetrics();
+      console.log("DEBUG: got metrics: ", response);
+      dispatch({ type: GET_METRICS_SUCCESS, payload: response });
+    } catch (error) {
+      console.error(`getMetricsAsync: ${toErrorStringWithHttpStatus(error)}`);
+      dispatch({
+        type: GET_METRICS_ERROR,
+        error: toErrorString(error),
+      });
+    }
+  };
+}