sprechstunden-go/config/config.go

151 lines
6.4 KiB
Go

// Package config implements the officeHours configuration
//
// It provides a struct type holding all necessary information for the programm.
// The configuration can be read from a JSON file.
package config
import (
"encoding/json"
"fmt"
"html/template"
"io/ioutil"
"log"
"net/mail"
)
// A Config holds all the constants for the programm.
// It is passed to most repositories.
type Config struct {
Server struct {
ListenAddress string // Address on which the http server is supposed to listen
ListenPort int // Port on which the http server is supposed to listen
Protocol string // Protocol to access the server; either "http" or "https"
Domain string // A string indicating the tool's base domain and path, e.g. "example.com/subfolder"
}
Date struct {
MinuteGranularity int // Restricts the minutes on which office hours can start and end to multiples of it.
MaxDuration int // Limits the length of office hours to minutes
EarliestStartTime struct {
Hour int
Minute int
}
LatestStartTime struct {
Hour int
Minute int
}
}
Request struct {
SecretLength int // Length of the secret token for requests
}
Mailer struct {
Type string // Send mail to "Stdout" or "Smtp"
FromAddress string // Send mail from this address
FromName template.HTML // Send mail from this name, e.g. "Office hours <officeHours@localhost>"
SmtpHost string // Host to use as smarthost
SmtpPort int // Port of the smarthost
SmtpUseAuth bool // Set whether to use authentication on the smarthosthost
SmtpIdentity string // Smarthost username
SmtpPassword string // Smarthost password
}
SQL struct {
Type string // Can be "SQLite" or "Mysql"
SQLiteFile string // Path to SQLite file
MysqlUser string
MysqlPassword string
MysqlHost string
MysqlPort int
MysqlDatabase string
}
Tutor struct {
MailSuffix string // Restrict mailaddresses of tutors to suffixes.
// e.g. "example.com" allowes "foo@example.com", "foo@sub.example.com", but not "foo@another.org" or "foo@barexample.com".
}
}
// ReadConfigFile takes a file path as an argument and attempts to
// unmarshal the content of the file into a struct containing a
// configuration.
func ReadConfigFile(filename string, conf *Config) error {
configData, err := ioutil.ReadFile(filename)
if err != nil {
err = fmt.Errorf("Error reading config file: %w", err)
log.Println(err.Error())
return err
}
err = json.Unmarshal(configData, conf)
if err != nil {
err = fmt.Errorf("Error parsing config file as json: %w", err)
log.Println(err.Error())
return err
}
return validateConfig(conf)
}
// Checks config for sane values (e.g. correct port range or database type).
func validateConfig(conf *Config) error {
var err error
if !(conf.Server.ListenPort >= 1 && conf.Server.ListenPort <= 65535) {
err = fmt.Errorf("Validating config: Server port must be between 1 and 65535, but is %d.", conf.Server.ListenPort)
log.Println(err.Error())
}
if !(conf.Server.Protocol == "http" || conf.Server.Protocol == "https") {
err = fmt.Errorf("Validating config: Server protocol must be 'http' or 'https', but is '%s'.", conf.Server.Protocol)
log.Println(err.Error())
}
if !(conf.Date.MinuteGranularity >= 1 && conf.Date.MinuteGranularity <= 60) {
err = fmt.Errorf("Validating config: Minute granularity must be between 1 and 60, but is %d.", conf.Date.MinuteGranularity)
log.Println(err.Error())
}
if !(conf.Date.EarliestStartTime.Hour >= 0 && conf.Date.EarliestStartTime.Hour <= 23) {
err = fmt.Errorf("Validating config: Earliest start time hour must be between 0 and 23, but is %d.", conf.Date.EarliestStartTime.Hour)
log.Println(err.Error())
}
if !(conf.Date.EarliestStartTime.Minute >= 0 && conf.Date.EarliestStartTime.Minute <= 60) {
err = fmt.Errorf("Validating config: Earliest start time minute must be between 0 and 60, but is %d.", conf.Date.EarliestStartTime.Minute)
log.Println(err.Error())
}
if !(conf.Date.MaxDuration >= conf.Date.MinuteGranularity && conf.Date.MaxDuration <= 4*60) {
err = fmt.Errorf("Validating config: Maximum duration must be between %d minute and 4 hours, but is %d.", conf.Date.MinuteGranularity, conf.Date.MaxDuration)
log.Println(err.Error())
}
if !(conf.Date.LatestStartTime.Hour >= 0 && conf.Date.LatestStartTime.Hour <= 23) {
err = fmt.Errorf("Validating config: Latest start time hour must be between 0 and 23, but is %d.", conf.Date.LatestStartTime.Hour)
log.Println(err.Error())
}
if !(conf.Date.LatestStartTime.Minute >= 0 && conf.Date.LatestStartTime.Minute <= 60) {
err = fmt.Errorf("Validating config: Latest start time minute must be between 0 and 60, but is %d.", conf.Date.LatestStartTime.Minute)
log.Println(err.Error())
}
if !(conf.Date.EarliestStartTime.Hour < conf.Date.LatestStartTime.Hour || (conf.Date.EarliestStartTime.Hour == conf.Date.LatestStartTime.Hour && conf.Date.EarliestStartTime.Minute < conf.Date.LatestStartTime.Minute)) {
err = fmt.Errorf("Validating config: Latest start time minute must be after earliest start time.")
log.Println(err.Error())
}
if !(conf.Request.SecretLength >= 5 && conf.Request.SecretLength <= 50) {
err = fmt.Errorf("Validating config: Requests' secret length must be between 5 and 50, but is %d.", conf.Request.SecretLength)
log.Println(err.Error())
}
if !(conf.Mailer.Type == "Stdout" || conf.Mailer.Type == "Smtp") {
err = fmt.Errorf("Validating config: Mailer type must be 'Stdout' or 'Smtp', but is '%s'.", conf.Mailer.Type)
log.Println(err.Error())
}
mailFromAddress, mailFromAddressErr := mail.ParseAddress(conf.Mailer.FromAddress)
if !(mailFromAddressErr == nil) {
err = fmt.Errorf("Validating config: Mail FromAddress could not be parsed (%w)", mailFromAddressErr)
log.Println(err)
} else {
if !(mailFromAddress.Name == "") {
err = fmt.Errorf("Validating config: Mail FromAddress must not contain a name value, but has '%s'", mailFromAddress.Name)
log.Println(err)
}
}
_, mailFromNameErr := mail.ParseAddress(string(conf.Mailer.FromName))
if !(mailFromNameErr == nil) {
err = fmt.Errorf("Validating config: Mail FromName could not be parsed (%w)", mailFromNameErr)
log.Println(err)
}
if !(conf.SQL.Type == "SQLite" || conf.SQL.Type == "Mysql") {
err = fmt.Errorf("Validating config: SQL type must be 'SQLite' or 'Mysql', but is '%s'.", conf.SQL.Type)
log.Println(err.Error())
}
return err
}