DEV Community

Build a RESTful API with the Serverless Framework

Sagar on October 19, 2018

Today, we’re going to implement serverless RESTful API services by using “Serverless Framework”. There are many cloud services provider offers serv...

Read full post

Magnus • Oct 20 '18

Oh, and one other thing: Is it possible to use mongoose+MongoDB instead of mysql+MySql? Any downside there?

If you were to use GraphQL, would that be instead of mysql?

Erick Gonzales • Oct 22 '18

Magnus I'm working right now in a project using the serverless framework, you can use mongoose+MongoDB (Cloud Atlas in my case) without any problems, what I like a lot about the serverless framework features is that you can handle a lot of cases in my case I'm working in a public API so you can configure custom authorizers and CORS management / rules. its very flexible framework.

Magnus • Oct 23 '18

Great, thanks for sharing Erick. I look forward to trying it.

Sagar • Oct 21 '18

For simplicity I choose MySQL but you can use any NOSQL database. There is single downside that for aws doesn't provide mongodb. If want to use mongodb then you have run ec2 instance for the same.

Srini Karlekar • Oct 21 '18

Check out mlab.com where you can run MongoDB in Serverless fashion. There is a free tier for running a single node MongoDB.

Sagar • Oct 21 '18

Wow!! It's good. I know that AWS Aurora provides serverless SQL engine. If MongoDB, providing serverless then its too good. Thanks for information.

Erick Gonzales • Oct 22 '18

Lambda + Cloud Atlas is a pretty good stack.

Sagar • Oct 23 '18

Hey Erick, I have not tried Cloud Atlas before it will be good if you send an email any link or reference for the same.

Erick Gonzales • Oct 23 '18

Hey Sagar, Sure I'll sent you an email.

Sagar • Oct 23 '18

Erick, I haven't not received email. You can DM me.

Comment deleted

Erick Gonzales • Oct 23 '18

Hey you can delete this one now.

Mubina Shaikh • Sep 24 '20 • Edited

Hi, Sagar, i was trying to implement Nodejs App with Mysql to build it serverless following your article, i get this error.

Serverless: Configuration warning at 'provider.runtime': should be equal to one of the allowed values [dotnetcore2.1, dotnetcore3.1, go1.x, java11, java8, java8.al2, nodejs10.x, nodejs12.x, provided, provided.al2, python2.7, python3.6, python3.7, python3.8, ruby2.5, ruby2.7]

i use below versions
Angular:- 10.1.2
Node:- 12.18.0
Mysql:- 8.0.17

please help me with the above error, i have followed same steps as mentioned in your article. (excepts for db config password)

Sagar • Sep 24 '20 • Edited

basically, you need to provide runtime in the serverless.yml file.

# serverless.yml
service: pokemon-service

provider:
  name: aws
  runtime: nodejs12.x // <-- here provide runtime
  stage: dev
  region: us-east-1
  memorySize: 512

Mubina Shaikh • Sep 25 '20

Hi Sagar,

Thank you for sharing, upon changing serverless.yml runtime to nodejs12.x, i am not getting the error i mentioned in previous comment.

I am attaching screenshots of calling API in postman i dont get response as shown in your article, and get pokemon by id API doesnt work at all.

Please let me knoew how to get data of API correctly.

Mubina Shaikh • Sep 25 '20 • Edited

dev-to-uploads.s3.amazonaws.com/i/...

Mubina Shaikh • Sep 25 '20

dev-to-uploads.s3.amazonaws.com/i/...

Mubina Shaikh • Sep 25 '20

Also, I tried to debug by putting console statements in index.js file API's but console statements are not printed in BE.

app.get('/pokemon/', (req, res) => {
const query = 'SELECT * FROM pokemon_tb'
pool.query(query, (err, results, fields) => {
if (err) {
const response = { data: null, message: err.message, }
console.log('***********', response);
res.send(response)
}

    const pokemons = [...results]
    const response = {
        data: pokemons,
        message: 'All pokemons successfully retrieved.',
    }
    res.send(response)
})

})

please tell me why ?

Sagar • Sep 25 '20

IDK exact reason behind this. you need crosscheck function with the article mention code blocks and also you've to debug the root cause of this.

Mubina Shaikh • Sep 25 '20

Hi, i had crossed checked function code blocks with article code blocks, its the same.
Can please tell me why console statements arent printing, it should print right ?

Adnan Rahić • Nov 29 '18

Great walkthrough! I've covered this topic in more detail with several different databases and scenarios. Have a look if you're interested.

I'd love some feedback!

Sagar • Dec 5 '18

Thank you 🙏🙇

Carlos Fuentes Novoa • May 14 '19

Hi Sagar First of all, thanks for the tutorial. It works perfect for me, but ... When I tried this code for the first time, I used my MySQL RDS variables and everything works fine, but when I use my localhost variables I get this error:

Serverless: GET /user (λ: testFunc)
Debug: internal, implementation, error
TypeError: Uncaught error: undefined is not iterable (cannot read property Symbol(Symbol.iterator))
at Query. (...\kpoapi-base\user.js:20:19)
at bound (domain.js:415:14)
at Query.runBound as _callback
at Query.Sequence.end (...\kpoapi-base\node_modules\mysql\lib\protocol\sequences\Sequence.js:83:24)
at ...\kpoapi-base\node_modules\mysql\lib\Pool.js:205:13
at Handshake.onConnect (...\kpoapi-base\node_modules\mysql\lib\Pool.js:58:9)
at bound (domain.js:415:14)
at Handshake.runBound as _callback
at Handshake.Sequence.end (...\kpoapi-base\node_modules\mysql\lib\protocol\sequences\Sequence.js:83:24)
at Handshake.ErrorPacket (...\kpoapi-base\node_modules\mysql\lib\protocol\sequences\Handshake.js:125:8)
at Protocol._parsePacket (...\kpoapi-base\node_modules\mysql\lib\protocol\Protocol.js:291:23)
at Parser._parsePacket (...\kpoapi-base\node_modules\mysql\lib\protocol\Parser.js:433:10)
at Parser.write (...\kpoapi-base\node_modules\mysql\lib\protocol\Parser.js:43:10)
at Protocol.write (...\kpoapi-base\node_modules\mysql\lib\protocol\Protocol.js:38:16)
at Socket. (...\kpoapi-base\node_modules\mysql\lib\Connection.js:91:28) at Socket. (...\kpoapi-base\node_modules\mysql\lib\Connection.js:522:10)
at Socket.emit (events.js:196:13)
at Socket.EventEmitter.emit (domain.js:494:23)
at addChunk (_stream_readable.js:290:12)
at readableAddChunk (_stream_readable.js:271:11)
at Socket.Readable.push (_stream_readable.js:226:10)
at TCP.onStreamRead (internal/stream_base_commons.js:166:17)

Obviously, I tried the connection using Workbench and I have no problem.
What could be happening?
I would appreciate any help from you. I hope you can help me.

Sagar • May 15 '19

Hi Carlos,thanks for your feedback. As per error stack, your trying to iterate over undefined.

Carlos Fuentes Novoa • May 15 '19

Hi Sagar, thanks for your response.
The problem, finally, was the type of authentication configured in my localhost of MySQL. I changed it to "Use Legacy Authentication Method" and the problem was solved. Thank you very much, again for your contributions.

Sagar • Oct 22 '18

In this article, I have used MySQL because of simplicity but you can try any database which you feel comfortable.

You can also try latest serverless database features.

Reference links:

Anirudh Ramesh • Oct 23 '18

Hey, Thank you very much for the post!
I had a quick question - Considering lambdas are short lived (3 or 5 mins if I am not wrong) - do we benefit from keeping a ConnectionPool?

Once the lambda lifecycle ends, would we not need to create this connection pool again?

If we keep creating this connection pool, isn't the purpose of pooling defeated?

Thanks!

Sagar • Oct 23 '18

Hi Anirudh, if we create a connection pool for each lambda then we're not reusing pool code. For code reusability, I have defined dbConfig.js file.

Magnus • Oct 20 '18 • Edited

Thanks, Sagar. Quick question. Isn't express used to create a web service so to say (I.e. the functionality of the server). Why do we need both Serverless and express? Probably a pretty basic question, it just confused me a bit.

Sagar • Oct 21 '18

Hey Magnus, good question.

We can create api in serverless without using express. But express is so powerful and creating api with express is so much simpler.

Lots of node developers are expert in express.

Nans Dumortier • Feb 20 '19

Hey, thank you for your article !
I'm also a bit confused with express. Does the express server starts everytime we receive a call ? Or is there something done with module.exports.handler = serverless(app) that does something that I don't understand yet ?

Makrand • Jun 19 '19

Hi Sagar, its an excellent sample. I just had a question, have you tried serving images while using serverless-http package. I am able to respond the images but i dont see the images being rendered. I thing there is some confusion with binary data. If possible can u share a sample with the image respose also.

Thanks!

Daniel Andrés Castillo Ardila • Jul 3 '20

Hey Sagar. Thanks in advance for the shared knowledge. I have a concern about it, you built a complete API in just one lambda function, I’m not sure if it’s a good practice but AWS recommends separating and dividing responsibilities inside a lambda funcion code. What do you think?

Sagar • Oct 22 '18 • Edited

Hi Trysm, you're absolutely right. To explains developer in the simplest way, I haven't included any best practices or validation. If it's production application then I will definitely use string interpolation and so many other stuff. Thanks for you're a suggestion.