app.js

process.SERVER_BUILD = true

const Koa = require("koa")
const Nuxt = require("nuxt").Nuxt
const Builder = require("nuxt").Builder
const koaRouter = require("koa-router")()
const config = require("./nuxt.config.js")
const router = require("./routes/index")
const mount = require("koa-mount")
const serve = require("koa-static")
const compress = require("koa-compress")
const http = require("http")
const path = require("path")
const staticCache = require("./plugins/staticCache")
require("./plugins/logger")

const app = new Koa()

config.dev = !(app.env === "production")
const isApiDev = app.env === "api-dev"
const isPm2Dev = app.env === "pm2-dev"
if(isApiDev || isPm2Dev){
    //强制false
    config.dev = false
}

const nuxt = new Nuxt(config)

// Build only in dev mode
if (config.dev) {
    // logger
    app.use(async function (ctx, next) {
        const start = new Date()
        await next()
        const ms = new Date() - start
        
        console.info(`koa:render ${ctx.method} ${ctx.url} - ${ms}ms`)
    });

    if(!isApiDev && !isPm2Dev){
        //API调试模式下，不build
        const builder = new Builder(nuxt)
        builder.build().catch((error) => {
            console.error(error) // eslint-disable-line no-console
            process.exit(1)
        })
    }
}

//http路由
router(koaRouter, app)
app.use(koaRouter.routes())
//缓存
if (!config.dev) {
    //gzip
    app.use(compress({
        filter: function (content_type) {
            return /js|css|jpe?g|png|gif|apk|svg/i.test(content_type)
        },
        threshold: 2048,
        flush: require("zlib").Z_SYNC_FLUSH
    }))
    //cdn回源
    app.use(mount("/static",serve("./.nuxt/dist",{maxage:24 * 60 * 60 * 7 * 1000, gzip:true})))

    app.use(staticCache(path.join(__dirname, "static"), {
        maxAge: 24 * 60 * 60 * 7,
        filter:["js","css","jpg","png","apk","svg"]
    }))
}

app.use(async function (ctx, next) {
    ctx.status = 200 // koa defaults to 404 when it sees that status is unset
    return new Promise((resolve, reject) => {
        ctx.res.on('close', resolve)
        ctx.res.on('finish', resolve)
        nuxt.render(ctx.req, ctx.res, promise => {
            // nuxt.render passes a rejected promise into callback on error.
            promise.then(resolve).catch(reject)
        })
    })
})

//for graceful reload
// process.on('SIGINT', function() {
//    db.stop(function(err) {
//      process.exit(err ? 1 : 0);
//    });
// });

app.listen(3000, "0.0.0.0", ()=>{
  console.info( `Server listening on 0.0.0.0:3000` )
})