tstor/config/handler.go

102 lines
1.9 KiB
Go
Raw Normal View History

package config
import (
"fmt"
"io/ioutil"
"os"
"path"
"github.com/ajnavarro/distribyted"
"github.com/sirupsen/logrus"
"gopkg.in/yaml.v3"
)
type EventFunc func(event string)
type ReloadFunc func(*Root, EventFunc) error
type Handler struct {
p string
reloadFunc ReloadFunc
}
func NewHandler(path string) *Handler {
return &Handler{p: path}
}
func (c *Handler) createFromTemplateFile() ([]byte, error) {
t, err := distribyted.HttpFS.Open("/templates/config_template.yaml")
if err != nil {
return nil, err
}
defer t.Close()
tb, err := ioutil.ReadAll(t)
if err != nil {
return nil, err
}
if err := os.MkdirAll(path.Dir(c.p), 0744); err != nil {
return nil, fmt.Errorf("error creating path for configuration file: %s, %w", c.p, err)
}
return tb, ioutil.WriteFile(c.p, tb, 0644)
}
func (c *Handler) GetRaw() ([]byte, error) {
f, err := ioutil.ReadFile(c.p)
if os.IsNotExist(err) {
logrus.WithField("file", c.p).Info("configuration file does not exist, creating from template file")
return c.createFromTemplateFile()
}
if err != nil {
return nil, fmt.Errorf("error reading configuration file: %w", err)
}
return f, nil
}
func (c *Handler) Get() (*Root, error) {
b, err := c.GetRaw()
if err != nil {
return nil, err
}
conf := &Root{}
if err := yaml.Unmarshal(b, conf); err != nil {
return nil, fmt.Errorf("error parsing configuration file: %w", err)
}
conf = AddDefaults(conf)
return conf, nil
}
func (c *Handler) OnReload(reloadFunc ReloadFunc) {
c.reloadFunc = reloadFunc
}
func (c *Handler) Reload(ef EventFunc) error {
if ef == nil {
ef = func(string) {}
}
conf, err := c.Get()
if err != nil {
return err
}
if c.reloadFunc != nil {
return c.reloadFunc(conf, ef)
}
return nil
}
func (c *Handler) Set(b []byte) error {
if err := yaml.Unmarshal(b, &Root{}); err != nil {
return fmt.Errorf("error parsing configuration file: %w", err)
}
return ioutil.WriteFile(c.p, b, 0644)
}