Merge pull request #16 from jokester/revise-demo

Revise demo

README.md

@@ -44,9 +44,7 @@ Prepend `publicaddr` wrapper to your `node` binary (or other interpreter like `t
 
 And [prebuild/prebuildify](https://github.com/prebuild/prebuildify) [prebuild/prebuildify-cross](https://github.com/prebuild/prebuildify-cross) [prebuild/node-gyp-build](https://github.com/prebuild/node-gyp-build/blob/master/node-gyp-build.js), they made shipping multiarch prebuilt native modules incredibly simple.
 
-## Demo
-
-### Simple usage
+## Demo: Rolling update between 2 versions without downtime
 
 Clone [this repo](https://github.com/jokester/publicaddr) and run multiple instances like:
 
@@ -55,22 +53,19 @@ git clone https://github.com/jokester/publicaddr
 
 cd publicaddr/demo
 
-npm install
+# run version a with 4 containers
+docker-compose up -d
 
-npm start &
-npm start &
-npm start &
-npm start &
+# start a HTTP benchmark
+wrk -t6 -c2000 -d120s http://127.0.0.1:3000 &
 
-wrk -t6 -c2000 -d10s http://127.0.0.1:3000 # or other HTTP benchmark tool
+# switch between version a / b, for a few times
+./switch-version.sh a b a b
 
-kill %1 %2 %3 %4
+# after benchmark ends
+docker-compose down
 ```
 
-### Inside containers
-
-Clone [this repo](https://github.com/jokester/publicaddr) and run `docker-compose up` in `demo/`
-
 ## License
 
 BSD

bin/publicaddr

@@ -23,7 +23,6 @@ if [ "x${SO_PATH}" != "x" ] && [ -f "$SO_PATH" ]; then
   set -x
   LD_PRELOAD="${SO_PATH} ${LD_PRELOAD:-}" exec "$@"
 else
-  echo "[publicaddr] native module not found. still execing next process."
-  set -x
-  exec "$@"
+  echo "[publicaddr] native module not found. your OS/platform may be unsupported."
+  exit 1
 fi

demo/Dockerfile

@@ -1,9 +1,9 @@
 # Dockerfile for demo
+# or, FROM node:18-alpine
 FROM node:18-bookworm-slim
 
-COPY . /opt/publicaddr
-
 RUN set -uex                         \
-        && cd /opt/publicaddr/demo   \
-        && npm i                     \
+        && npm i -g publicaddr@0.4.3 \
         && npm cache clean --force
+
+COPY ./demo-server.mjs /opt/demo-server.mjs

demo/demo-server.mjs

@@ -0,0 +1,62 @@
+import http from 'node:http';
+const wait = timeout => new Promise(f => setTimeout(f, timeout))
+const waitRandom = (min, max) => wait(min + Math.random() * (max - min))
+
+const processTag = `demo-server-version-${process.env.VERSION ?? '?'}-${Math.random().toString(16).slice(2, 10)}`
+
+let reqCount = 0
+let onFlight = 0
+
+const server = http.createServer(async (req, res) => {
+    ++onFlight;
+    res.writeHead(200, undefined,
+        // { connection: 'Close' }
+    );
+    await waitRandom(20, 100);
+    res.end(`reqCount: ${++reqCount} from ${processTag}`)
+    --onFlight;
+})
+
+function log(...args) {
+    console.info(`${Date.now().toFixed(2)} ${processTag}:`, ...args)
+}
+
+async function waitRequestsEnd() {
+    while (onFlight > 0) {
+        await wait(1e3)
+    }
+}
+
+function startReportCount() {
+    let lastReqCountReported = 0
+    const interval = 10 // s
+    const timer = setInterval(() => {
+        const delta = reqCount - lastReqCountReported
+        lastReqCountReported = reqCount
+        log(`reqCount: ${reqCount}`);
+        log(`mean RPS: ${(delta / interval).toFixed(2)}`);
+    }, interval * 1e3)
+    return () => clearInterval(timer)
+}
+
+async function main() {
+    const port = Number(process.env.PORT || 3000)
+    const gotSignal = new Promise((resolve, reject) => {
+        process.on('SIGINT', resolve)
+        process.on('SIGTERM', resolve)
+    })
+    const stopReportCount = startReportCount()
+
+    server.listen(port, () => {
+        log(`listening on port ${port}`)
+    })
+    await gotSignal
+    const error = await new Promise(f => server.close(f))
+    if (error) {
+        console.error('server close error:', error)
+    }
+    stopReportCount()
+    log(`app closing.`)
+}
+
+await main();

demo/docker-compose.yaml

@@ -1,30 +1,26 @@
 version: "3"
 services:
-  demo-server-g1: &demo-server
-    # build:
-    #   context: ..
-      # dockerfile: demo/Dockerfile
-      # dockerfile: demo/Dockerfile-alpine
-    image: ${SLOT1_IMAGE}
-    command: npm start
-    working_dir: /opt/publicaddr/demo
+  # see https://iximiuz.com/en/posts/multiple-containers-same-port-reverse-proxy/ for explanation
+  sandbox:
+    image: alpine
+    command: sleep infinity
+    ports:
+      - 3000:3000
+
+  demo-server-a: &demo-server
+    build: .
+    command: publicaddr node /opt/demo-server.mjs
+    network_mode: service:sandbox
+    environment:
+      VERSION: 'a'
     deploy:
-      replicas: ${SLOT1_REPLICA:-4}
-    # NOTE I have no idea how to get default network_mode (requires port mapping) + replica working
-    # network_mode=host (and perhaps some other) works with SO_REUSEPORT
-    network_mode: host
+      replicas: ${VERSION_A_REPLICA:-4}
 
-  # with publicaddr one can even do zero-downtime rollout
-  #
-  # e.g.
-  # 0. Start with g1.replica=6 g2.replica=0  # Users only see reply from g1
-  # 1. Set new image in g2
-  # 2. Set g1.replicas=3 g1.replicas=3
-  # 3. docker-compose up -d                  # user starts to see reply from g1 / g2
-  # 4. Set g1.replicas=0 g2.replicas=6
-  # 5. docker-compose up -d                  # user starts to see reply from g2
-  demo-server-g2:
-    <<: *demo-server
-    image: ${SLOT2_IMAGE}
+  demo-server-b: &demo-server
+    build: .
+    command: publicaddr node /opt/demo-server.mjs
+    network_mode: service:sandbox
+    environment:
+      VERSION: 'b'
     deploy:
-      replicas: ${SLOT2_REPLICA:-0}
+      replicas: ${VERSION_B_REPLICA:-0}