pm2 nuxt js example

ecosystem.config.js

// production usage at your own risk

const fs = require("fs");
let numberOfProcesses = 1;
let maxMemory = 128;
let maxMemoryPerInstance = 128;
if (fs.existsSync("/run/config.json")) {
  const pshConfig = require("/run/config.json");

  // on grid environments, we don't want to round up to not run too many processes
  if (pshConfig.info.limits.cpu > 1) {
    numberOfProcesses = Math.floor(pshConfig.info.limits.cpu);
  }

  // on DG3 environments we can safely round up
  if (process.env.PLATFORM_MODE) {
    numberOfProcesses = Math.ceil(pshConfig.info.limits.cpu);
  }

  maxMemory = pshConfig.info.limits.memory;

  // Distribute the available memory across all instances
  maxMemoryPerInstance = Math.ceil(maxMemory / numberOfProcesses);
}

module.exports = {
  apps: [
    {
      name: "index",
      script: "./index.js",
      // args: `start -c ${process.cwd()}/nuxt.config.js`,
      cwd: '/app',
      instances: numberOfProcesses,
      exec_mode: "cluster",
      max_memory_restart: `${maxMemoryPerInstance}M`,
      node_args: `--max_old_space_size=${maxMemoryPerInstance}`,
    },
  ],
};

.platform.app.yaml modifications

dependencies:
  nodejs:
    pm2: ^5.3.0

pm2 needs a mount

mounts:
  "run":
    source: local
    source_path: run
  ".cache":
    source: local
    source_path: cache
  ".pm2":
    source: local
    source_path: pm2

new start command

web:
  commands:
    start: NUXT_PORT=$PORT PM2_HOME=$PLATFORM_APP_DIR/.pm2 pm2-runtime start ecosystem.config.js

nuxt.config.js modification
we will need this at the root level (telemetry messes with the start command and due to the pm2 setup we need to specify the build + root dir to nuxt)

rootDir: process.cwd(),
buildDir: process.cwd() + '/.nuxt/',
telemetry: false