badguardhome/upgrade.go

106 lines
2.6 KiB
Go

package main
import (
"fmt"
"io/ioutil"
"log"
"os"
"path/filepath"
"gopkg.in/yaml.v2"
)
// Performs necessary upgrade operations if needed
func upgradeConfig() error {
// read a config file into an interface map, so we can manipulate values without losing any
configFile := filepath.Join(config.ourBinaryDir, config.ourConfigFilename)
if _, err := os.Stat(configFile); os.IsNotExist(err) {
log.Printf("config file %s does not exist, nothing to upgrade", configFile)
return nil
}
diskConfig := map[string]interface{}{}
body, err := ioutil.ReadFile(configFile)
if err != nil {
log.Printf("Couldn't read config file '%s': %s", configFile, err)
return err
}
err = yaml.Unmarshal(body, &diskConfig)
if err != nil {
log.Printf("Couldn't parse config file '%s': %s", configFile, err)
return err
}
schemaVersionInterface, ok := diskConfig["schema_version"]
log.Printf("%s(): got schema version %v", _Func(), schemaVersionInterface)
if !ok {
// no schema version, set it to 0
schemaVersionInterface = 0
}
schemaVersion, ok := schemaVersionInterface.(int)
if !ok {
err = fmt.Errorf("configuration file contains non-integer schema_version, abort")
log.Println(err)
return err
}
if schemaVersion == currentSchemaVersion {
// do nothing
return nil
}
return upgradeConfigSchema(schemaVersion, &diskConfig)
}
// Upgrade from oldVersion to newVersion
func upgradeConfigSchema(oldVersion int, diskConfig *map[string]interface{}) error {
switch oldVersion {
case 0:
err := upgradeSchema0to1(diskConfig)
if err != nil {
return err
}
default:
err := fmt.Errorf("configuration file contains unknown schema_version, abort")
log.Println(err)
return err
}
configFile := filepath.Join(config.ourBinaryDir, config.ourConfigFilename)
body, err := yaml.Marshal(diskConfig)
if err != nil {
log.Printf("Couldn't generate YAML file: %s", err)
return err
}
err = safeWriteFile(configFile, body)
if err != nil {
log.Printf("Couldn't save YAML config: %s", err)
return err
}
return nil
}
func upgradeSchema0to1(diskConfig *map[string]interface{}) error {
log.Printf("%s(): called", _Func())
// The first schema upgrade:
// No more "dnsfilter.txt", filters are now kept in data/filters/
dnsFilterPath := filepath.Join(config.ourBinaryDir, "dnsfilter.txt")
_, err := os.Stat(dnsFilterPath)
if !os.IsNotExist(err) {
log.Printf("Deleting %s as we don't need it anymore", dnsFilterPath)
err = os.Remove(dnsFilterPath)
if err != nil {
log.Printf("Cannot remove %s due to %s", dnsFilterPath, err)
// not fatal, move on
}
}
(*diskConfig)["schema_version"] = 1
return nil
}