app.keys = ["token"];

...

ctx.cookies.set("jt", "abcd", {
 signed: true,
});

Set-Cookie: jt=abcd; path=/; httponly
Set-Cookie: jt.sig=gpDbdxr25sarDhE_1yMSAnIn_bU; path=/; httponly

app.on('error', (err, ctx) => {
 // 記錄異常日志
 console.error(err);
});

app.use((ctx) => {
 ctx.throw(400, '參數(shù)錯(cuò)誤');
});

app.on('error', (err, ctx) => {
 // 記錄異常日志
 console.error(err);
});

app.use(async(ctx, next) => {
 try {
  await next()
 } catch (err) {
  let status = 500;
  const message = err.message;
  // koa的throw使用http-errors來生成error
  // 此處只判斷是否有status，有則認(rèn)為是http-errors
  if (err.status) {
   status = err.status
  } else {
   // 非主動(dòng)拋出異常，則觸發(fā)error事件，記錄異常日志
   ctx.app.emit("error", err, ctx);
  }
  ctx.status = status;
  ctx.body = {
   message,
  };
 }
})

app.use((ctx) => {
 // 代碼異常
 // ctx.i.j = 0;
 // 主動(dòng)拋出異常
 ctx.throw(400, '參數(shù)錯(cuò)誤');
});

let processingCount = 0;
const maxProcessingCount = 1000;
app.use(async (ctx, next) => {
 processingCount++;
 if (processingCount > maxProcessingCount) {
  // 如果需要也可以直接在處理請求超時(shí)時(shí)，直接出錯(cuò)
  console.error("processing request over limit");
 }
 try {
  await next();
 } catch (err) {
  throw err; 
 } finally {
  processingCount--;
 }
});

app.use(async (ctx) => {
 // 延時(shí)一秒
 await new Promise(resolve => setTimeout(resolve, 1000));
 ctx.body = {
  account: 'vicanso',
 };
});

function delayResponse(delayMs) {
 const delay = (t) => {
  const d = delayMs - (Date.now() - t);
  // 如果處理時(shí)長已超過delayMs，無需等待
  if (d <= 0) {
   return Promise.resolve();
  }
  return new Promise(resolve => setTimeout(resolve, d));
 }
 return async(ctx, next) => {
  const startedAt = Date.now();
  try {
   await next();
   // 成功處理時(shí)等待
   await delay(startedAt);
  } catch (err) {
   // 失敗時(shí)也等待
   await delay(startedAt);
   throw err;
  }
 }
}

router.post('/users/v1/register', delayResponse(1000), (ctx) => {
 ctx.body = {
  account: 'vicanso',
 };
});

function stats() {
 let connecting = 0;
 const spdyList = [
  100,
  300,
  1000,
  3000,
 ];
 return async (ctx, next) => {
  const start = Date.now();
  const tags = {
   method: ctx.method,
  };
  connecting++;
  const fields = {
   connecting,
   url: ctx.url,
  }
  let status = 0;
  try {
   await next();
  } catch (err) {
   // 出錯(cuò)時(shí)狀態(tài)碼從error中獲取
   status = err.status;
   throw err;
  } finally {
   // 如果非出錯(cuò)，則從ctx中取狀態(tài)碼
   if (!status) {
    status = ctx.status;
   }
   const use = Date.now() - start;
   connecting--;
   tags.route = ctx._matchedRoute;
   tags.type = `${status / 100 | 0}`
   let spdy = 0;
   // 確認(rèn)處理時(shí)長所在區(qū)間
   spdyList.forEach((v, i) => {
    if (use > v) {
     spdy = i + 1;
    }
   });
   tags.spdy = `${spdy}`;

   fields.use = use;
   fields.bytes = ctx.length || 0;
   fields.code = status;
   fields.ip = ctx.ip;
   // 統(tǒng)計(jì)數(shù)據(jù)寫入統(tǒng)計(jì)系統(tǒng)（如influxdb）
   console.info(tags);
   console.info(fields);
  }
 };
}

app.use(stats());

router.post('/users/v1/:type', async (ctx) => {
 await new Promise(resolve => setTimeout(resolve, 100))
 ctx.body = {
  account: 'vicanso',
 };
});

function tracker() {
 const stringify = (data) => JSON.stringify(data, (key, value) => {
  // 對于隱私數(shù)據(jù)做***處理
  if (/password/.test(key)) {
   return '***';
  }
  return value;
 });
 return async (ctx, next) => {
  const trackerInfo = {
   url: ctx.url,
   form: ctx.request.body,
  };
  try {
   await next();
  } catch (err) {
   trackerInfo.error = err.message;
   throw err;
  } finally {
   trackerInfo.params = ctx.params;
   if (!trackerInfo.error) {
    trackerInfo.body = ctx.body;
   }
   console.info(stringify(trackerInfo))
  }
 };
}

app.use(bodyParser());
app.use(tracker());

router.post('/users/v1/:type', async (ctx) => {
 // ctx.throw(400, '密碼出錯(cuò)');
 await new Promise(resolve => setTimeout(resolve, 100))
 ctx.body = {
  account: 'vicanso',
 };
});

function validate(data, schema) {
 const result = Joi.validate(data, schema);
 if (result.error) {
  // 出錯(cuò)可創(chuàng)建自定義的校驗(yàn)出錯(cuò)類型
  throw result.error;
 }
 return result.value;
}

router.post('/users/v1/register', async (ctx) => {
 const data = validate(ctx.request.body, Joi.object({
  // 賬號限制長度為3-20個(gè)字符串
  account: Joi.string().min(3).max(20).required(),
  // 密碼限制長度為6-30，而且只允許字母與數(shù)字
  password: Joi.string().regex(/^[a-zA-Z0-9]{6,30}$/).required(),
  email: Joi.string().email().optional(),
 }));
 ctx.body = {
  account: data.account,
 };
});

const userSchema = {
 // 賬號限制長度為3-20個(gè)字符串
 account: () => Joi.string().min(3).max(20),
 // 密碼限制長度為6-30，而且只允許字母與數(shù)字
 password: () => Joi.string().regex(/^[a-zA-Z0-9]{6,30}$/),
 email: () => Joi.string().email(),
}

router.post('/users/v1/register', async (ctx) => {
 const data = validate(ctx.request.body, Joi.object({
  account: userSchema.account().required(),
  password: userSchema.password().required(),
  email: userSchema.email().optional(),
 }));
 ctx.body = {
  account: data.account,
 };
});