kevlars

README

Kevlars

A golang backend development kits to accelerate building services.

Background

Having to write over and over again something like logger, db connection, caching, audit log, rest client, grpc client, telemetry, config/secret, healthcheck, feature flag, and so on. I find it waste a lot of time, while it should be re-usable everywhere in multiple service. There-fore come to mind to build a development kits to help me reach that goal. During those development process in private, I find it that this might help anyone whom has the same goal as mine. Thus, I decide to make this project open source. To anyone using this library and have feedback or would like to contribute, please don't hesitate to do so.

Usage

Since on of the purpose of this development kit to accelerate building backend service, below we can see how easy and fast we can scaffold new RESTful API.

scaffold.
    NewApp(scaffold.WithScope("restful_api")).
    WithDatabases().
    RunRestApiUseEcho(func(app *scaffold.Application, e *echo.Echo) {
        // do something such as routing and needed process
        // all resources that instantiate above (e.g. WithDatabase) are available under `app`
        // for example: 
        // if we want to get config value:
        // app.Config().GetString("key")
        // if we want to use database connection:
        // app.DefaultDB().Exec(ctx, q, args...)
})

Another sample when we need to run service as GRPC Server, it would simply be done by following sample:

scaffold.
    NewApp(scaffold.WithScope("restful_api")).
    WithDatabases().
    RunGrpcServer(run func(app *Application, rpcServer *grpc.Server)) {
        // do something such as register proto and needed process
        // all resources that instantiate above (e.g. WithDatabase) are available under `app`
        // for example: 
        // if we want to get config value:
        // app.Config().GetString("key")
        // if we want to use database connection:
        // app.DefaultDB().Exec(ctx, q, args...)
})

For more samples, can refer to directory examples in this repository.

Structure

Captcha

This package is used to generate captcha image and validate user input.

Note: currently only support generating base64 encoded image.

To use this package, simply import it and use it like below:

cb64 := captcha.NewB64(captcha.B64WithType(captcha.B64TypeDigit)).MustInit()
// generate base 64 image
// capId => is the captcha id use to validate
// capImg => base 64 encoded image
capId, _, capImg := cb64.Generate()

// to verify user input:
// userInput => should be the variable contains the value of user input
// capId => use the generated id above
isValid := cb64.Verify(capId, userInput, true)
fmt.Println(isValid)

Messaging

This package is used to send messaging. Currently only support sending message to telegram. Will add other provider as things progress. To use this package, simply import it and use it like below:

tgSender := messaging.NewTelegramSender(
        messaging.TelegramWithTarget(app.Config().GetString("messaging.telegram.default_target")),
        messaging.TelegramWithToken(app.Config().GetString("messaging.telegram.token")),
        messaging.TelegramWithSanitizer(messaging.StandardSanitizer()), 
    ).MustInit()
err := tgSender.SendMessage(`hello!`)
fmt.Println(err)