Log tail

README.md

@@ -32,7 +32,14 @@ your can change the port adding `-e "port=xxx"` param
 
 See the content of `docker` directory. There are Dockerfile and docker-compose template. E.g. run `docker build -f docker/Dockerfile -t abaplint-backend .` to build your image from scratch.
 
-TODO: https docker compose, logging advices
+*TODO: https docker compose, logging advices*
+
+### Env variables
+
+The package respects `.env` file (must not be committed to the repo though!). Here are the available variables:
+
+- PORT - port to listen at
+- ALB_SUPPRESS_FRONPAGE_LOG - disable frontpage log: set `1` to disable
 
 ## Development
 
@@ -50,3 +57,5 @@ Useful scripts
 - docker
   - `bin/docker-build.sh` - build docker container from command line (supposes bash environment)
   - `bin/docker-run.sh` - run the built above container
+
+See also: [docker dev notes](./docker/dev-notes.md)

docker/Dockerfile

@@ -27,6 +27,6 @@ COPY ["package*.json", "LICENSE", "./"]
 RUN npm ci --quiet --only=production && npm cache clean --force --silent
 COPY --from=builder /usr/src/app/build/ ./build
 
-# HEALTHCHECK --interval=30s CMD node healthcheck.js ?
+# HEALTHCHECK --interval=30s CMD node healthcheck.js ? or curl localhost/healthz = OK ?
 
 ENTRYPOINT [ "/sbin/tini", "--", "node", "build/server.js" ]

src/api/index.ts

@@ -1,36 +1,42 @@
 import * as express from "express";
 import {checkObject} from "./check_object";
+import { addInfoEx } from "../lib/log-tail";
 
 const router = express.Router();
 
 router.use(express.json({limit: "50mb"}));
 router.use(express.urlencoded({limit: "50mb", extended: false}));
 
 router.post("/ping", (_req, res) => {
-  // addInfo("ping, " + new Date());
+  addInfoEx("ping");
   res.json({ success: true, payload: "abap is forevah!" });
 });
 
 router.post("/check_file", (req, res) => {
   // TODO validate request
   // TODO define response type ?
   // TODO capture exceptions, return json with error
+  const hrstart = process.hrtime();
   const result = checkObject(req.body);
-  // addInfo("check_file, " +
-  //   result.object.objectType + " " +
-  //   result.object.objectName + ", " +
-  //   result.issues.length + " issues, " +
-  //   new Date() + ", " +
-  //    req.socket.bytesRead + " bytes");
+  const hrend = process.hrtime(hrstart);
+  addInfoEx([
+    "check_file",
+    result.object.objectType,
+    result.object.objectName,
+    `${result.issues.length} issues`,
+    `${req.socket.bytesRead} bytes`,
+    `${(hrend[0] * 1000 + hrend[1] / 1000000).toFixed()} ms`,
+  ]);
   res.json(result);
 });
 
 // app.post("/api/v1/check_configuration",
 // app.post("/api/v1/get_default_configuration",
 // app.post("/api/v1/pretty_print",
 
-router.all("*", (_req, res) => {
-  return res.status(404).json({ success: false, error: { message: "Wrong API call" } });
+router.all("*", (req, res) => {
+  addInfoEx("unexpected API call: " + req.originalUrl);
+  res.status(404).json({ success: false, error: { message: "Wrong API call" } });
 });
 
 export default router;

src/app.ts

@@ -3,27 +3,22 @@ import * as morgan from "morgan";
 import * as helmet from "helmet";
 import { frontPage } from "./front_page";
 import api from "./api";
+import { addInfoEx } from "./lib/log-tail";
 
 const app  = express();
 
-// const info: string[] = [];
-
-// function addInfo(s: string): void {
-//   info.push(s);
-//   if (info.length > 10) {
-//     info.shift();
-//   }
-// }
-
 if (process.env.NODE_ENV !== "test") {
   // app.use(cors());
   app.use(helmet());
   app.use(morgan("common"));
 }
 
-app.get("/", (_req, res) => res.send(frontPage([])));
+app.get("/", (_req, res) => res.send(frontPage()));
 app.get("/healthz", (_req, res) => res.send("OK"));
 app.use("/api/v1", api);
-app.use("*", (_req, res) => res.status(404).send("forbidden") );
+app.use("*", (req, res) => {
+  addInfoEx("unexpected request: " + req.originalUrl);
+  res.status(404).send("forbidden");
+});
 
 export default app;

src/front_page.ts

@@ -1,5 +1,6 @@
 import * as abaplint from "@abaplint/core";
 import * as os from "os";
+import { getLogTail } from "./lib/log-tail";
 
 function osInfo(): string {
   return "load: " + os.loadavg() + "<br>" +
@@ -10,7 +11,16 @@ function osInfo(): string {
     "cpus: " + JSON.stringify(os.cpus()) + "<br>";
 }
 
-export function frontPage(info: string[]): string {
+function renderLogTail(): string {
+  if (process.env.ALB_SUPPRESS_FRONPAGE_LOG === "1") {
+    return "";
+  } else {
+    const info = getLogTail();
+    return info.join("<br>");
+  }
+}
+
+export function frontPage(): string {
   return `<!DOCTYPE html>
 <html>
   <head>
@@ -21,7 +31,7 @@ export function frontPage(info: string[]): string {
     <hr>
     ${osInfo()}
     <hr>
-    ${info.join("<br>")}
+    ${renderLogTail()}
   </body>
 </html>
 `;

src/lib/log-tail.test.ts

@@ -0,0 +1,10 @@
+import { addInfo, getLogTail } from "./log-tail";
+
+test("should add", () => {
+  addInfo("hello");
+  addInfo("world");
+  expect(getLogTail()).toEqual([
+    "hello",
+    "world",
+  ]);
+});

src/lib/log-tail.ts

@@ -0,0 +1,29 @@
+const logTail: string[] = [];
+let tailLength = 10; // default
+
+export function setTailLength(newTailLength: number): void {
+  if (newTailLength <= 0) {
+    throw Error("Unexpected tailLength");
+  }
+  tailLength = newTailLength;
+}
+
+export function addInfo(s: string): void {
+  logTail.push(s);
+  if (logTail.length > tailLength) {
+    logTail.shift();
+  }
+}
+
+export function getLogTail(): string[] {
+  return logTail;
+}
+
+export function formatDate(date: Date): string {
+  return date.toISOString().substr(0, 19).replace("T", " ");
+}
+
+export function addInfoEx(entries: string | string[]): void {
+  entries = Array.isArray(entries) ? entries : [entries];
+  addInfo([ formatDate(new Date()), ...entries ].join(", "));
+}