CCM-12649 Get Status healthcheck endpoint

infrastructure/terraform/components/api/README.md

@@ -37,6 +37,7 @@ No requirements.
 | <a name="module_get_letter"></a> [get\_letter](#module\_get\_letter) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.24/terraform-lambda.zip | n/a |
 | <a name="module_get_letter_data"></a> [get\_letter\_data](#module\_get\_letter\_data) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.24/terraform-lambda.zip | n/a |
 | <a name="module_get_letters"></a> [get\_letters](#module\_get\_letters) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.24/terraform-lambda.zip | n/a |
+| <a name="module_get_status"></a> [get\_status](#module\_get\_status) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.24/terraform-lambda.zip | n/a |
 | <a name="module_kms"></a> [kms](#module\_kms) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.20/terraform-kms.zip | n/a |
 | <a name="module_logging_bucket"></a> [logging\_bucket](#module\_logging\_bucket) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.20/terraform-s3bucket.zip | n/a |
 | <a name="module_patch_letter"></a> [patch\_letter](#module\_patch\_letter) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.24/terraform-lambda.zip | n/a |

infrastructure/terraform/components/api/iam_role_api_gateway_execution_role.tf

@@ -52,7 +52,8 @@ data "aws_iam_policy_document" "api_gateway_execution_policy" {
       module.get_letter.function_arn,
       module.get_letters.function_arn,
       module.patch_letter.function_arn,
-      module.get_letter_data.function_arn
+      module.get_letter_data.function_arn,
+      module.get_status.function_arn
     ]
   }
 }

infrastructure/terraform/components/api/locals.tf

@@ -12,6 +12,7 @@ locals {
     GET_LETTERS_LAMBDA_ARN  = module.get_letters.function_arn
     GET_LETTER_DATA_LAMBDA_ARN  = module.get_letter_data.function_arn
     PATCH_LETTER_LAMBDA_ARN  = module.patch_letter.function_arn
+    GET_STATUS_LAMBDA_ARN = module.get_status.function_arn
   })
 
   destination_arn = "arn:aws:logs:${var.region}:${var.shared_infra_account_id}:destination:nhs-main-obs-firehose-logs"

infrastructure/terraform/components/api/module_lambda_get_status.tf

@@ -0,0 +1,78 @@
+module "get_status" {
+  source = "https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.24/terraform-lambda.zip"
+
+  function_name = "get_status"
+  description   = "Healthcheck for service"
+
+  aws_account_id = var.aws_account_id
+  component      = var.component
+  environment    = var.environment
+  project        = var.project
+  region         = var.region
+  group          = var.group
+
+  log_retention_in_days = var.log_retention_in_days
+  kms_key_arn           = module.kms.key_arn
+
+  iam_policy_document = {
+    body = data.aws_iam_policy_document.get_status_lambda.json
+  }
+
+  function_s3_bucket      = local.acct.s3_buckets["lambda_function_artefacts"]["id"]
+  function_code_base_path = local.aws_lambda_functions_dir_path
+  function_code_dir       = "api-handler/dist"
+  function_include_common = true
+  handler_function_name   = "getStatus"
+  runtime                 = "nodejs22.x"
+  memory                  = 128
+  timeout                 = 5
+  log_level               = var.log_level
+
+  force_lambda_code_deploy = var.force_lambda_code_deploy
+  enable_lambda_insights   = false
+
+  send_to_firehose          = true
+  log_destination_arn       = local.destination_arn
+  log_subscription_role_arn = local.acct.log_subscription_role_arn
+
+  lambda_env_vars = merge(local.common_lambda_env_vars, {
+    MAX_LIMIT = var.max_get_limit
+  })
+}
+
+data "aws_iam_policy_document" "get_status_lambda" {
+  statement {
+    sid    = "KMSPermissions"
+    effect = "Allow"
+
+    actions = [
+      "kms:Decrypt",
+      "kms:GenerateDataKey",
+    ]
+
+    resources = [
+      module.kms.key_arn, ## Requires shared kms module
+    ]
+  }
+
+  statement {
+    sid    = "AllowDynamoDBAccess"
+    effect = "Allow"
+
+    actions = [
+      "dynamodb:DescribeTable"
+    ]
+
+    resources = [
+      aws_dynamodb_table.letters.arn,
+      "${aws_dynamodb_table.letters.arn}/index/supplierStatus-index"
+    ]
+  }
+
+
+  statement {
+    sid       = "S3ListAllMyBuckets"
+    actions   = ["s3:ListAllMyBuckets"]
+    resources = ["arn:aws:s3:::*"]
+  }
+}

infrastructure/terraform/components/api/resources/spec.tmpl.json

@@ -23,6 +23,39 @@
   },
   "openapi": "3.0.1",
   "paths": {
+    "/_status": {
+      "get": {
+        "operationId": "getStatusId",
+        "responses": {
+          "200": {
+            "description": "Empty body"
+          },
+          "500": {
+            "description": "Server error"
+          }
+        },
+        "security": [
+          {
+            "LambdaAuthorizer": []
+          }
+        ],
+        "summary": "Healthcheck endpoint",
+        "x-amazon-apigateway-integration": {
+          "contentHandling": "CONVERT_TO_TEXT",
+          "credentials": "${APIG_EXECUTION_ROLE_ARN}",
+          "httpMethod": "POST",
+          "passthroughBehavior": "WHEN_NO_TEMPLATES",
+          "responses": {
+            ".*": {
+              "statusCode": "200"
+            }
+          },
+          "timeoutInMillis": 29000,
+          "type": "AWS_PROXY",
+          "uri": "arn:aws:apigateway:${AWS_REGION}:lambda:path/2015-03-31/functions/${GET_STATUS_LAMBDA_ARN}/invocations"
+        }
+      }
+    },
     "/letters": {
       "get": {
         "description": "Returns 200 OK with paginated letter ids.",

internal/datastore/src/__test__/heathcheck.test.ts

@@ -0,0 +1,38 @@
+import { DynamoDBDocumentClient } from "@aws-sdk/lib-dynamodb";
+import { DBHealthcheck } from "../healthcheck";
+import { createTables, DBContext, deleteTables, setupDynamoDBContainer } from "./db";
+
+// Database tests can take longer, especially with setup and teardown
+jest.setTimeout(30000);
+
+describe('DBHealthcheck', () => {
+
+  let db: DBContext;
+
+  beforeAll(async () => {
+    db = await setupDynamoDBContainer();
+  });
+
+  beforeEach(async () => {
+    await createTables(db);
+  });
+
+  afterEach(async () => {
+    await deleteTables(db);
+  });
+
+  it('passes when the database is available', async () => {
+    const dbHealthCheck = new DBHealthcheck(db.docClient, db.config);
+    await dbHealthCheck.check();
+  });
+
+  it('fails when the database is unavailable', async () => {
+    const realFunction = db.docClient.send;
+    db.docClient.send = jest.fn().mockImplementation(() => { throw new Error('Failed to send')});
+
+    const dbHealthCheck = new DBHealthcheck(db.docClient, db.config);
+    await expect(dbHealthCheck.check()).rejects.toThrow();
+
+    db.docClient.send = realFunction;
+  });
+});

internal/datastore/src/healthcheck.ts

@@ -0,0 +1,13 @@
+import { DescribeTableCommand } from "@aws-sdk/client-dynamodb";
+import { DynamoDBDocumentClient } from "@aws-sdk/lib-dynamodb";
+import { LetterRepositoryConfig } from "./letter-repository";
+
+export class DBHealthcheck {
+  constructor(readonly ddbClient: DynamoDBDocumentClient,
+    readonly config: LetterRepositoryConfig) {}
+
+  async check(): Promise<void> {
+    await this.ddbClient.send(new DescribeTableCommand({
+      TableName: this.config.lettersTableName}));
+  }
+}

internal/datastore/src/index.ts

@@ -1,3 +1,4 @@
 export * from './types';
 export * from './letter-repository';
+export * from './healthcheck';
 export * from './types';

lambdas/api-handler/src/config/__tests__/deps.test.ts

@@ -1,4 +1,3 @@
-
 import type { Deps } from '../deps';
 
 describe('createDependenciesContainer', () => {
@@ -24,6 +23,7 @@ describe('createDependenciesContainer', () => {
     // Repo client
     jest.mock('../../../../../internal/datastore', () => ({
       LetterRepository: jest.fn(),
+      DBHealthcheck: jest.fn()
     }));
 
     // Env

lambdas/api-handler/src/config/deps.ts

@@ -2,13 +2,14 @@ import { S3Client } from "@aws-sdk/client-s3";
 import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
 import { DynamoDBDocumentClient } from '@aws-sdk/lib-dynamodb';
 import pino from 'pino';
-import { LetterRepository } from '../../../../internal/datastore';
+import { LetterRepository, DBHealthcheck } from '../../../../internal/datastore';
 import { envVars, EnvVars } from "../config/env";
 
 export type Deps = {
   s3Client: S3Client;
   letterRepo: LetterRepository;
-  logger: pino.Logger,
+  dbHealthcheck: DBHealthcheck;
+  logger: pino.Logger;
   env: EnvVars
 };
 
@@ -23,13 +24,25 @@ function createLetterRepository(log: pino.Logger, envVars: EnvVars): LetterRepos
   return new LetterRepository(docClient, log, config);
 }
 
+function createDBHealthcheck(envVars: EnvVars): DBHealthcheck {
+  const ddbClient = new DynamoDBClient({});
+  const docClient = DynamoDBDocumentClient.from(ddbClient);
+  const config = {
+    lettersTableName: envVars.LETTERS_TABLE_NAME,
+    ttlHours: envVars.LETTER_TTL_HOURS
+  };
+
+  return new DBHealthcheck(docClient, config);
+}
+
 export function createDependenciesContainer(): Deps {
 
   const log = pino();
 
   return {
     s3Client: new S3Client(),
     letterRepo: createLetterRepository(log, envVars),
+    dbHealthcheck: createDBHealthcheck(envVars),
     logger: log,
     env: envVars
   };

lambdas/api-handler/src/handlers/__tests__/get-letter-data.test.ts

@@ -18,7 +18,7 @@ import { makeApiGwEvent } from './utils/test-utils';
 import { ValidationError } from '../../errors';
 import * as errors from '../../contracts/errors';
 import { createGetLetterDataHandler } from '../get-letter-data';
-import { S3Client } from '@aws-sdk/client-s3';
+import { Destination, S3Client } from '@aws-sdk/client-s3';
 import pino from 'pino';
 import { LetterRepository } from '../../../../../internal/datastore/src';
 import { EnvVars } from '../../config/env';
@@ -37,7 +37,7 @@ describe('API Lambda handler', () => {
       LETTER_TTL_HOURS: 12960,
       DOWNLOAD_URL_TTL_SECONDS: 60
     } as unknown as EnvVars
-  }
+  } as Deps;
 
   beforeEach(() => {
     jest.clearAllMocks();

lambdas/api-handler/src/handlers/__tests__/get-letter.test.ts

@@ -28,7 +28,7 @@ describe('API Lambda handler', () => {
       DOWNLOAD_URL_TTL_SECONDS: 60,
       MAX_LIMIT: 2500
     } as unknown as EnvVars
-  };
+  } as Deps;
 
   beforeEach(() => {
     jest.clearAllMocks();

lambdas/api-handler/src/handlers/__tests__/get-letters.test.ts

@@ -38,7 +38,7 @@ describe('API Lambda handler', () => {
       DOWNLOAD_URL_TTL_SECONDS: 60,
       MAX_LIMIT: 2500
     } as unknown as EnvVars
-  }
+  } as Deps;
 
   beforeEach(() => {
     jest.clearAllMocks();

lambdas/api-handler/src/handlers/__tests__/get_status.test.ts

@@ -0,0 +1,83 @@
+import { S3Client } from "@aws-sdk/client-s3";
+import { DBHealthcheck } from "../../../../../internal/datastore/src";
+import pino from "pino";
+import { Deps } from "../../config/deps";
+import { makeApiGwEvent } from "./utils/test-utils";
+import { mockDeep } from "jest-mock-extended";
+import { Context } from "aws-lambda";
+import { createGetStatusHandler } from "../get-status";
+
+describe('API Lambda handler', () => {
+  it('passes if S3 and DynamoDB are available', async() => {
+
+    const event = makeApiGwEvent({path: '/_status',
+      headers: {'nhsd-supplier-id': 'supplier1', 'nhsd-correlation-id': 'correlationId', 'x-request-id': 'requestId'}
+    });
+
+    const getLetterDataHandler = createGetStatusHandler(getMockedDeps());
+    const result = await getLetterDataHandler(event,  mockDeep<Context>(), jest.fn());
+
+    expect(result).toEqual({
+      statusCode: 200,
+      body: JSON.stringify({}, null, 2),
+    });
+  });
+
+  it('fails if S3 is unavailable', async() => {
+    const mockedDeps = getMockedDeps();
+    mockedDeps.s3Client.send = jest.fn().mockRejectedValue(new Error('unexpected error'));
+
+    const event = makeApiGwEvent({path: '/_status',
+      headers: {'nhsd-supplier-id': 'supplier1', 'nhsd-correlation-id': 'correlationId', 'x-request-id': 'requestId'}
+    });
+
+    const getLetterDataHandler = createGetStatusHandler(mockedDeps);
+    const result = await getLetterDataHandler(event,  mockDeep<Context>(), jest.fn());
+
+    expect(result).toEqual(expect.objectContaining({
+      statusCode: 500
+    }));
+  });
+
+
+  it('fails if DynamoDB is unavailable', async() => {
+    const mockedDeps = getMockedDeps();
+    mockedDeps.dbHealthcheck.check = jest.fn().mockRejectedValue(new Error('unexpected error'));
+
+    const event = makeApiGwEvent({path: '/_status',
+      headers: {'nhsd-supplier-id': 'supplier1', 'nhsd-correlation-id': 'correlationId', 'x-request-id': 'requestId'}
+    });
+
+    const getLetterDataHandler = createGetStatusHandler(mockedDeps);
+    const result = await getLetterDataHandler(event,  mockDeep<Context>(), jest.fn());
+
+    expect(result).toEqual(expect.objectContaining({
+      statusCode: 500
+    }));
+  });
+
+  it('fails if request ID is absent', async() => {
+    const event = makeApiGwEvent({path: '/_status',
+      headers: {'nhsd-supplier-id': 'supplier1', 'nhsd-correlation-id': 'correlationId'}
+    });
+
+    const getLetterDataHandler = createGetStatusHandler(getMockedDeps());
+    const result = await getLetterDataHandler(event,  mockDeep<Context>(), jest.fn());
+
+    expect(result).toEqual(expect.objectContaining({
+      statusCode: 500
+    }));
+  });
+
+  function getMockedDeps(): jest.Mocked<Deps> {
+    return {
+      s3Client: { send: jest.fn()} as unknown as S3Client,
+      dbHealthcheck: {check: jest.fn()} as unknown as DBHealthcheck,
+      logger: { info: jest.fn(), error: jest.fn() } as unknown as pino.Logger,
+      env: {
+        SUPPLIER_ID_HEADER: 'nhsd-supplier-id',
+        APIM_CORRELATION_HEADER: 'nhsd-correlation-id'
+      }
+    } as Deps;
+  }
+});

lambdas/api-handler/src/handlers/__tests__/patch-letter.test.ts

@@ -57,7 +57,7 @@ describe('patchLetter API Handler', () => {
       LETTER_TTL_HOURS: 12960,
       DOWNLOAD_URL_TTL_SECONDS: 60
     } as unknown as EnvVars
-  }
+  } as Deps;
 
   it('returns 200 OK with updated resource', async () => {
     const event = makeApiGwEvent({