Merge pull request #18 from pagopa/add_healthcheck

Add Healthcheck endpoint

docker-compose.yml

@@ -66,10 +66,8 @@ services:
             - spid-net
 
     storage:
-        image: azurite
-        build:
-            context: ./
-            dockerfile: docker/azurite/Dockerfile
+        container_name: storage
+        image: mcr.microsoft.com/azure-storage/azurite
         ports:
             - "10000:10000"
             - "10001:10001"

src/app.ts

@@ -48,6 +48,7 @@ import {
   EntityType
 } from "@pagopa/io-spid-commons/dist/utils/middleware";
 import { AdeAPIClient } from "./clients/ade";
+import { healthcheckHandler } from "./handlers/general";
 import { logger } from "./utils/logger";
 import { REDIS_CLIENT } from "./utils/redis";
 
@@ -255,6 +256,8 @@ export const createAppTask = withSpid({
     });
   });
 
+  withSpidApp.get("/healthcheck", healthcheckHandler(redisClient));
+
   withSpidApp.post("/introspect", introspectHandler);
 
   withSpidApp.post("/invalidate", invalidateHandler);

src/handlers/general.ts

@@ -0,0 +1,42 @@
+import * as express from "express";
+import { toError } from "fp-ts/lib/Either";
+import {
+  fromEither,
+  fromLeft,
+  taskEither,
+  tryCatch
+} from "fp-ts/lib/TaskEither";
+import { RedisClient } from "redis";
+import { AdeAPIClient } from "../clients/ade";
+import { getConfigOrThrow } from "../utils/config";
+import { errorsToError } from "../utils/conversions";
+import { pingTask } from "../utils/redis_storage";
+
+const config = getConfigOrThrow();
+
+export const healthcheckHandler = (redisClient: RedisClient) => (
+  _: express.Request,
+  res: express.Response
+) =>
+  // first ping for redis
+  pingTask(redisClient)
+    .chain(() =>
+      // if Attribute Authority is enabled check for service is up&running
+      config.ENABLE_ADE_AA
+        ? tryCatch(
+            () => AdeAPIClient(config.ADE_AA_API_ENDPOINT).ping({}),
+            toError
+          )
+            .chain(__ => fromEither(__).mapLeft(errs => errorsToError(errs)))
+            .chain(response =>
+              response.status === 200
+                ? taskEither.of(true)
+                : fromLeft(new Error(response.value.detail))
+            )
+        : taskEither.of(true)
+    )
+    .fold(
+      err => res.status(500).json(err.message),
+      () => res.status(200).json("OK")
+    )
+    .run();

src/utils/redis_storage.ts

@@ -3,6 +3,23 @@ import { fromNullable, Option } from "fp-ts/lib/Option";
 import { fromEither, TaskEither, tryCatch } from "fp-ts/lib/TaskEither";
 import { RedisClient } from "redis";
 
+/**
+ * Parse a Redis given string reply.
+ *
+ * @see https://redis.io/topics/protocol#simple-string-reply.
+ */
+export const givenStringReply = (
+  err: Error | null,
+  reply: string | undefined,
+  message: string
+): Either<Error, boolean> => {
+  if (err) {
+    return left<Error, boolean>(err);
+  }
+
+  return right<Error, boolean>(reply === message);
+};
+
 /**
  * Parse a Redis single string reply.
  *
@@ -162,3 +179,19 @@ export const existsKeyTask = (
       ),
     toError
   ).chain(fromEither);
+
+export const pingTask = (redisClient: RedisClient): TaskEither<Error, true> =>
+  tryCatch(
+    () =>
+      new Promise<Either<Error, true>>(resolve =>
+        redisClient.ping("ping message", (err, response) =>
+          resolve(
+            falsyResponseToError(
+              givenStringReply(err, response, "ping message"),
+              new Error("Error while pinging redis")
+            )
+          )
+        )
+      ),
+    toError
+  ).chain(fromEither);