Welcome in the node-red workshop !

Short presentation

TODO

Objectives

At the end this workshop, you should be able to create a simple api with node-red Simple means you will be able to create a register/login, create task(s) attribute to one user.

Installation (node-red)

• Clone this repository & move into the directory
• start docker docker-compose up (it will run node-red & mongodb)

source: https://nodered.org/docs/getting-started/local

Security (source : https://nodered.org/docs/user-guide/runtime/securing-node-red)

By default, the Node-RED editor is not secured - anyone who can access its IP address can access the editor and deploy changes.

Let's securise it !

You will need to edit the settings.js in the .node-red folder...

If you want to go in this folder, you will need to run the cmd in the docker container:

• get the container id with : docker ps

• run the bash of the container : docker exec -it <container id> /bin/bash

• Welcome in the bash of the contrainer

• generate a password and copy the result : npx node-red-admin hash-pw (Don't forget to kill it ! You will get something like this : "$2a$08$71Vr0fW17O1Jl1BzfA7NGOYO6dSSANyZBwLxdr0QFd..0O3ihpzoS")

• Edit the settings.js file : vi /data/settings.js

• Welcome in hell... (vim), go near the line 123, you will find a adminAuth object, just uncomment with the X key (or press I to get the insert mode) (uncomment line 123 -> 130)

• With the insert mode change the password by the password you generated earlier

• quit & save vi (ESC + :wq or ESC + maj + ZZ)

• if you want to leave the docker container bash : ctrl + D

• turn off docker (ctrl + C), restart docker (docker-compose up)

Installation (mongodb)

• install MongoDB Compass (https://www.mongodb.com/download-center/compass)

• connect to the local database (user: dev & password: dev)

Getting start

Node-red is setup and "securised" !

You can go on this page : http://127.0.0.1:1880/

Hello world

• First drag-&-drop from the palette inject and debug into the workspace

• Wire inject to debug

• Double click on inject and change his value (modify timestamp to string for example)

• Click on deploy (on the top right corner) & click on the button on the left of inject. You will see in the debug tab (on the top right corner) the value of inject

what have we done ?

inject node to "inject" information/variable in the flow

Structure des informations

If you look at the debug button (named : msg.payload), you can see it return the content of msg.paylaod.

Node red use the playload object to pass variable between nodes.

switch & change & template

The switch node is like a "if", if the condition in the node isn't good, it won't let it pass.

The change node is like a = in js, it change a value.

The template node just "format" a response and return a string.

In this example:

• first I put a inject to inject a value in the flow (value : 5)
• then I check with a switch if the value is <= 5 or < 5
• after the switch I use a set node to modify the payload to "failed" or "sucess" (it depend of the switch)
• finaly I format the string with a template node
• (last node is a console.log)

Api time !

Basically, node-red already have everything you need to connect the client & the server.

In the network block of the palette, you will find http in, http response, http request and more other network things...

But there is no node aboud database. The next step will help to install "new" node to manage your database (mongodb in this case)

Setup

• first you will need to install mongodb2 (2 because the first version isn't really complete) in node-red

• click on the menu icon in the top right of the window and click in settings
  

• in the user settings popup, click on Palette and on the install tab

• search for mongodb2 (node-red-contrib-mongodb2) and install it

• you'll need to install node-red-contrib-objectid, it will help you to search by the id of the object in the database/collection

• after the installation you should find a mongodb2 in in your nodes (in the storage bock) and an objectid node (in the function bock)

Hello world (api - get /hello)

• drag&drop a http in node and edit his proteries

• drag&drop a http response

• place a template node between them and edit it to return "hello world"

You should have something like this:

• try in your natigator : http://127.0.0.1:1880/hello, you should see Hello world

Register & login (+setup mongodb connection)

• drag&drop a mongodb2 in from the palette to the workspace

• edit it

  • edit the server to get this (user :dev, password dev)

• First step: we will insert a todo in the database in the collection todo so in the collection field of mongodb2 just write todo and change to operation to get insertOne
  

• now you can add a http in node and configure it as post and for the /newUser ("verification" just mean, if you want to do a real api, you should put some condictions there)
  if you want to check the result you can test your route with postman. If you don't know how to use postman just click here !

• now let's login, use the same parten as newUser but with findOne and not insertOne
  How do fineOne and insertOne work ?
  It's very simple: when you call insertOne it will put in the database all the payload object ! So if you put the "email" and the "password" in body of your http request, it will put the "email" and the "password" in the database. (It only work with mongodb).
  What about findOne ?
  findOne will check every document of you collection and check if all properties of the payload (and his value) is in a document of the collection.

  If findOne doesn't have a match, it will just return null

• Try it with postman ! Normaly the return of register should be like this:

{
    "n": 1,
    "ok": 1
}

• and the result of loginshould be like this:

{
    "_id": "5dd5a491c1d8080010bd0992",
    "email": "plow",
    "pw": "plow"
}

Now keep this _id, it will be usefull in your next request with postman, we will use it as "login token".

Good job you just finished the login part !

If you have any question about this part, just ask them :)

Create a task (insert again)

Ok, insert something is easy... Now, you know how to do it ! But we will make it bit more complicated. if you don't specify anything, every user will see every task of every one... And we don't want it...

Earlier, I told you to save the _id of the user when you did the login request with postman. It's time to use it now.

In postman just place this _id in a new headers called Authorization like this:

• To create a task and assign it to a user, you will need a http in node, http response node, mongodb2 in node (with insertOne) and... a function node !
  In fact, you will need to write few code lines...
  But what will we do ? And what will we write ?
  We need to find the id in the headers (msg.req.headers.authorization) and put it in the idUser property in the msg.payload
  Test in postman without forget to write the authorization in the headers tab
  

Find all task of a user

Find all task from a user is like the previous one but with a find.toArray and not insertOne

Find a task by his id (and only if the user get it!)

In mongodb, the _id isn't a string so we have to transforme it into a ObjectId to do this, you installed objectid node. It convert the msg.payload._id (string) to msg.payload._id (object) !

Don't worry, I will help you !

Like the 2 previous one, you will need to use a http in but you need to put :id at the end. It means this route have a "paramater" (like a variable)

Now we need to put the id and the userid in the msg.payload object to do a query.

Now we need to convert the _id (string) to _id (objectid) with the objectid node (in the function block)

You did it !

Good job ! You did it !
You did 80% of a CRUD API, the 20 others percents are the delete/modify routes and few verification for the security or things like "You can't have 2 sames email in the database"...

The biggest question is...