Go custom struct validation – the idiomatic way

In the previous blog, we had gone over struct validations in golang using validator library. Continuing on, in this blog, we’ll cover custom validations.

Let’s say for the below struct:

type Config struct {
    ServerUrl string
    AppPort   int
}

We could validate our struct with validations provided by the library like:

import (
    "fmt"
    "github.com/go-playground/validator"
    "strings"
)

func Validate(config Config) bool {
    validate := validator.New()
    validationErr := validate.Struct(config)
    if validationErr != nil {
        return false    
    }
    return true
}

Now onto the topic of custom validations.

Say, we want to check whether ServerUrl field is an HTTPS URL
The straight forward way would be to introduce a function:

func customValidator(config Config) bool {
    value :=