LEARNING BUFFALO
MY ADVENTURE IN GOLANG
Intro
After finishing a fun and simple way creating hello world in GO, I decided to extend the learning adventure into web framework. My choice is Buffalo, because some web recommended me to do so. I will try other framework as well but that is for later writing. My plan in this will be
1. Setting Environment. I think it’s already set
2. Install Buffalo. Based on https://gobuffalo.io/en/docs/getting-started/installation. Install scoop check, Install buffalo check.
3. Follow The Document. From here https://gobuffalo.io/en/docs/getting-started/new-project
Follow The Document
Based on https://gobuffalo.io/en/docs/getting-started/new-project I will begin my own adventure. I hope I found a new error.
So it says I have to create my new application on my GOPATH
I will not do that. I’m going to create in another folder. And I found some error
as usual I just copy paste the error message with keyword golang. And stackoverflow answer with
let’s go install the thing. And see if it resolve.
After restarting visual studio code, and the messages says successfully built. I guess it’s resolve.
Next to do is start the app. I did “$ buffalo dev” But again bump into error. Well the document said “Generate project” so generate is done. But it says the app need database if you look into error messages
the getting started didn’t said anything about database and database configuration. So I just go into the files and found out that Readme.md said something about the database.
I think this one at Readme.md should be mention in the Getting Started document https://gobuffalo.io/en/docs/getting-started/new-project and place it before running the app. After looking into the doc, it is said that I have to look into Database section before running the app.
I guess I need to read better. Well anyway this one is screencap from Readme.md
You’ll need a postgres as default database, and edit the configuration in database.yml file, don’t forget to comment out test and production.
After that you can go start the $ buffalo pop create -a command. It will automatically create the database.
Then you can run $ buffalo dev as Readme.md mention it. If it’s work fine, you can view it in browser
go to http://localhost:3000/ and if you see this, then it’s working.
Reading Database Section
After this I decided to read the Database section https://gobuffalo.io/en/docs/db/getting-started/ it’s a quite heavy reading, but if you are already familiar with other programming languages like Nodejs this should be easier to understand. If you just started coding and your choice is Go then you don’t have to read all of this in one go, just comeback when you need an information. For example, usually I read the first one and then I’ll try it without finishing the whole article. And after few days I’ll encounter relationship or migration or something else related to database but I don’t know how the correct Go approach, then I’ll read some more. I think that it’s important to try it at least once before continuing to read.
Reading Routing Section
Again if you already experienced in ExpressJS you’ll catch up quick, but it always nice to read it once. https://gobuffalo.io/en/docs/routing/
Reading Action Section
Umm yeah good read. https://gobuffalo.io/en/docs/actions/ have a good tools to generate the files and code at the same time.
Reading Resources Section
This one section is very interesting for me. It generate CRUD for a table in one go along with the needed view. If you look into the code, it show a standard CRUD operation.
But what if we got a relation with another table? Apparently if you read at https://gobuffalo.io/en/docs/resources/#nesting-resources section it covers the question.
Reading Context Section
I don’t understand this one. https://gobuffalo.io/en/docs/context/
Reading Request Binding
https://gobuffalo.io/en/docs/bind/. So model can bind into form or json/xml
Reading Middleware
Again it’s good read, and of course I will use already existing middleware rather than create my own.
Reading The rest of Request Handling Section
Session and cookies, I think this one still the same as other programming language.
Conclusion from Reading a few article
Are this reading can make you a website with GO ? Yes, a simple one. Without Authentication and Authorization.
So what to do if I want to make a website complete with Authentication and Authorization also User Management with Role based Access ? Of course you need to google more.
Finding a Complete Website
My complete website is a website that have User Management module with Role Based Access and a good Authentication and Authorization middleware.
So how are we gonna achieve this ? Like I said before we need to google more. And with google more I found this article https://blog.john-pfeiffer.com/golang-buffalo-tutorial-to-create-a-web-site-with-authentication. It explain to use minimal Authentication and Authorization. But I can’t seem to find Role based one.
So let’s start making one. For a little bit of design in RBAC you can read these article https://elang2.github.io/myblog/posts/2018-09-29-Role-Based-Access-Control-MicroServices.html
, but for a starter I think I just need to create a simple one. For the first try, I gonna do a simple User Auth then moving to User management, then add the simple Roles Based Access.
I found some tutorial in creating buffalo with JWT its here https://www.littlewire.dev/2020/03/buffalo-auth/
Creating a simple User Authentication and Authorization
I create this based on article from littlewire https://www.littlewire.dev/2020/03/buffalo-auth/ and if you also look into https://github.com/gobuffalo/authrecipe the code almost the same, anyway so let’s jump into it. Before this I already create the coke app using $ buffalo new coke, without the –api like the article tells you.
Following Article
Up to User Action section everything works fine, until I tested Create User and found error which said “no transaction found” as you can see below. Maybe because the buffalo version is not the same or the imported library is different.
This is the result
// before create
func (u *User) BeforeCreate(tx *pop.Connection) error {
hash, err := bcrypt.GenerateFromPassword([]byte(u.Password), bcrypt.DefaultCost)
if err != nil {
return errors.WithStack(err)
}
u.Password = string(hash)
return nil
}
// Validate gets run every time you call a "pop.Validate*" (pop.ValidateAndSave, pop.ValidateAndCreate, pop.ValidateAndUpdate) method.
// This method is not required and may be deleted.
func (u *User) Validate(tx *pop.Connection) (*validate.Errors, error) {
var err error
return validate.Validate(
&validators.StringIsPresent{Field: u.Email, Name: "Email"},
&validators.StringIsPresent{Field: u.Password, Name: "Password"},
&validators.FuncValidator{
Field: u.Email,
Name: "Email",
Message: "%s is already taken",
Fn: func() bool {
var b bool
q := tx.Where("email = ?", u.Email)
if u.ID != uuid.Nil {
q = q.Where("id != ?", u.ID)
}
b, err = q.Exists(u)
if err != nil {
return false
}
return !b
},
},
), nil
}
Anyway now I understand that the code from litewire maybe have different version then the one I’m using. I’m just gonna restart everything again and I hope I found what went wrong from my code.
It's not done yet. my aim is to make web service with Authorization, Authentication, User Management, maybe Role Base Accsess
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