bnkamalesh/webgo

package webgo

import (
    "encoding/json"
    "os"
    "strconv"
    "time"
)

// Config is used for reading app's configuration from json file
type Config struct {
    // Host is the host on which the server is listening
    Host string `json:"host,omitempty"`
    // Port is the port number where the server has to listen for the HTTP requests
    Port string `json:"port,omitempty"`

    // CertFile is the TLS/SSL certificate file path, required for HTTPS
    CertFile string `json:"certFile,omitempty"`
    // KeyFile is the filepath of private key of the certificate
    KeyFile string `json:"keyFile,omitempty"`
    // HTTPSPort is the port number where the server has to listen for the HTTP requests
    HTTPSPort string `json:"httpsPort,omitempty"`

    // ReadTimeout is the maximum duration for which the server would read a request
    ReadTimeout time.Duration `json:"readTimeout,omitempty"`
    // WriteTimeout is the maximum duration for which the server would try to respond
    WriteTimeout time.Duration `json:"writeTimeout,omitempty"`

    // InsecureSkipVerify is the HTTP certificate verification
    InsecureSkipVerify bool `json:"insecureSkipVerify,omitempty"`

    // ShutdownTimeout is the duration in which graceful shutdown is completed
    ShutdownTimeout time.Duration

    // ReverseMiddleware if true, will reverse the order of execution middleware
    // from the order of it was added. e.g. router.Use(m1,m2), m2 will execute first
    // if ReverseMiddleware is true
    ReverseMiddleware bool
}

// Load config file from the provided filepath and validate
func (cfg *Config) Load(filepath string) {
    file, err := os.ReadFile(filepath)
    if err != nil {
        LOGHANDLER.Fatal(err)
    }

    err = json.Unmarshal(file, cfg)
    if err != nil {
        LOGHANDLER.Fatal(err)
    }

    err = cfg.Validate()
    if err != nil {
        LOGHANDLER.Fatal(ErrInvalidPort)
    }
}

// Validate the config parsed into the Config struct
func (cfg *Config) Validate() error {
    i, err := strconv.Atoi(cfg.Port)
    if err != nil {
        return ErrInvalidPort
    }

    if i <= 0 || i > 65535 {
        return ErrInvalidPort
    }

    return nil
}