category: Firebase

Firebase - Firebase functions 使用紀錄

on 2019-12-20

Firebase - Firebase functions 使用紀錄

最近想把一些自己在用的小東西丟到 severless 的服務

因為之前發生過一次 server 掛掉過一次的情況

當時是 GCP CE 不知為何 VM 中的網卡設定出問題

整個網卡消失

然後外部根本連不進去

最後請教大大後

只好開一個新的 instance 然後把原本的那個儲存空間掛到新開的 instance

因為那台平常在試驗的 server

裡面亂七八糟而且大多的 code 都不會做 git 控管

所以就想說把一些常用的功能用 serverless 拆出來好了

就想說來研究一下火了一陣子然後設定沒設定好就會噴一堆預算和安全性問題的 Firebase 所推出的 functions

其實 GCP 自己本身也有 cloud functions

但我這是玩票性質的

所以就先用 firebase functions 來試試啦

先說一下目前 firebase functions 只支援 Nodejs

但是 Google cloud 的 cloud functions 支援 Nodejs python golnag

  1. 首先先裝 firebase-tools CLI
npm install -g firebase-tools
  1. 執行 firebase login
firebase login
  1. 到要建立 functions 的資料夾

這時候要注意如果你要做版本控管

就是直接到該 repository 的目錄下即可

下一步會在這目錄建立需要的程式

  1. 執行 firebase init functions
firebase init functions

過程中會請你選擇或新開專案

這邊的專案是指 firebase 上面的專案

可以用 JavaScript 寫或 TypeScript 寫 code

整個 functions 的結構

myproject
 +- .firebaserc    # Hidden file that helps you quickly switch between
 |                 # projects with `firebase use`
 |
 +- firebase.json  # Describes properties for your project
 |
 +- functions/     # Directory containing all your functions code
      |
      +- .eslintrc.json  # Optional file containing rules for JavaScript linting.
      |
      +- package.json  # npm package file describing your Cloud Functions code
      |
      +- index.js      # main source file for your Cloud Functions code
      |
      +- node_modules/ # directory where your dependencies (declared in
                       # package.json) are installed

要注意的事和開始寫扣啦

index.js 就是 functions 會執行的程式

你可以依照自己的需求安裝需要的 node 套件

但需要注意的是該套件安裝完你的 package.json 的 dependencies 必須有紀錄該套件的版號

package.json 中的

"engines": {
  "node": "8"
}

表示使用的 node 版本

目前預設是 8

10 有支援但目前是 beta

可以看目前文件來決定用哪一版的 nodejs

exports.ok = functions.https.onRequest((request, response) => {
 response.send("Hello from Firebase!");
});

ok 就會是實際上 url path

上線後的 url 會是

http://<region>-<firebase project name>.cloudfunctions.net/<exports name>

ex:
http://us-central1-my-project.cloudfunctions.net/ok

相關 API 可以參考

很多 API 都和 express 幾乎一樣

如果要帶參數的話可以用 params

部署區域

可以決定該功能在那個區域部署

同一個 index 檔案可以部署不同地區

預設是 us-central1 (Iowa) 艾荷華

可以查看支援的 region 列表

只要添加在 code 之中即可

exports.ok = functions.region('asia-northeast1').https.onRequest((request, response) => {
...

目前沒法在程式中直接設定 multi region 得一個一個上

不然官方是建議建立不同 region 的 entry

modify-region

再把 function 邏輯抽象出來就可以了

本地測試

可以參考Run functions locally

會在本地開啟 local server

也會有對應的 url path 可以讓你直接點

如果要測試 log

在 node 中寫

console.log()
console.info()
console.error()
console.warn()

就可以了

呼叫第三方或外部 api 時出現 EAI_AGAIN

查了一下

這是 DNS 解析的問題

在 Free 方案只允許呼叫 Google service 自己的 api

要切到付費方案才可以

用 Blaze plan 就可以了

Refer - getaddrinfo EAI_AGAIN api.sendgrid.com:443

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Firebase - Firebase Cloud Message(FCM) Research Log

on 2016-12-08

Firebase - Firebase Cloud Message(FCM) Research Log

This article is focus on web version

Intro

You can easy to use web notification push notification to your web site.

Set Up a JavaScript Firebase Cloud Messaging Client App

Different with use pure web notification

Using the Notifications API

  • Browser support
    • FCM - Chrome(desktop & Android) & Firefox(desktop & Android)
    • pure notification api - Chrome(desktop & Android) & Firefox(desktop & Android) & Opera(desktop) & Safari(desktop)
      • Android need service worker
  • Service Worker
    • FCM - require
    • pure notification api - option

pure web notification only a notification object, you need handle connection push message from server.

But FCM had handle this connect.

web notification demo

FCM demo

FCM push service

Different whith use Service Worker or not use Service Worker

use Service Worker no use Service Worker
service open on browser tab and focus receive receive
service open on browser tab and not focus receive receive
service open not on browser tab receive can’t receive

Prepare

  • app server
    • a server can send message
  • HTTPS
  • manifest.json
    • set gcm send id

Step

  1. Use firebase console create a project(If you had project for your web service, you can skip this setp

  2. Overview -> setting -> cloud message and you can get YOUR-SERVER-KEY & SENDER-ID

  3. And then you can use the simple code from https://github.com/firebase/quickstart-js/tree/master/messaging

FCM Flow

What is Instance ID?

Web notification dosen’t have Instance ID so we only can use token

Base flow

base flow

App server

Build it to send message or do something like send topic message or personal message

Use HTTP or XMPP

Firebase Cloud Messaging HTTP Protocol

Personal push

You can bind user info & their token created from client web browser, then you can push personal message for user.

And it use api push notification like this

https://fcm.googleapis.com/fcm/send
Content-Type:application/json
Authorization:key=AIzaSyZ-1u...0GBYzPu7Udno5aA

{ "data": {
    "score": "5x1",
    "time": "15:10"
  },
  "to" : "bk3RNwTe3H0:CI2k_HHwgIpoDKCIZvvDMExUdFQ3P1..."
}

Authorization key is Firebase console server key

Reference - Build App Server Send Requests

Multiple device push

Send Messages to Multiple Devices

It’s base on sub / pub pattern, you can reference Publish/Subscribe pattern - MSDN - Microsoft

Two way

  1. topic(suggest) Suggest use this, it’s fast and easy to use

  2. group

If you want to know any token push status and tracking which in this group, you can use group way

But you must handle group yourself

Group send request format

About Tracking

FCM web notification not support analytics

So you can add querystring on action url or add log on receive message on foreground

Error handle

If user clear token on offline, need handle cleared token let app server and IID server know

Two way can handle this thing

  1. client initiative handle

If your web service provide unsubscribe function, you must handle this behavior.

And you need handle if user clear data from client, you need update token.

Firebase’s api messaging.deleteToken() handle delete from IID server but delete token from app server need handle yourself.

  1. server side detect

When server push notification and response error make some error handle like delete InvalidRegistration token

And you can log token active time, if long time not active, you can delete it from app server and also suggest delete it from IID server

Notice

On desktop device Chrome or Firefox not on process it can not receive message

But message will queued until Browser open

So don’t worried about this thing

  • Notice don’t send error target user

  • Notice don’t send the push token that doesn’t had any user or device

And then i find Firebase hosting seem doesn’t support service worker, so it can’t use FCM on Firebase hosting.

Receive Messages in a JavaScript Client

Reference - Using the Notifications API - Web APIs | MDN

instance-id

Reference - Publish/Subscribe pattern - MSDN - Microsoft

Reference - What Makes a Good Notification?

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