kdnotify/handler/handler.go
Paul Stemmet 315a334732
handler: types and funcs for handling notify events
The primary type exported is VrrpHandler, which interprets the given
WatchRules, applying them as necessary.

It implements watcher.MsgHandler, and can be considered the primary
implementation.
2022-12-09 18:05:59 +00:00

86 lines
1.7 KiB
Go

/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/.
*/
package handler
import (
"text/template"
"git.st8l.com/luxolus/kdnotify/config"
n "git.st8l.com/luxolus/kdnotify/schema/notify"
)
type VrrpHandler struct {
Config *config.WatchConfig
Cxt *config.LibCxt
}
type TemplateEnv struct {
Cxt any
Event MessageEvent
}
type MessageEvent struct {
Type string
State string
Instance string
}
func NewVrrp(cxt *config.LibCxt, cfg *config.WatchConfig) *VrrpHandler {
return &VrrpHandler{
Config: cfg,
Cxt: &config.LibCxt{
Logger: cxt.Logger.Named("handler"),
Context: cxt.Context,
},
}
}
func (h *VrrpHandler) ProcessVrrp(msg n.VrrpMessage) error {
log, matches := h.Cxt.Logger.Sugar(), 0
for _, rule := range h.Config.Rules {
if rule.Match(&msg) {
matches += 1
env := h.newTemplateEnv(&msg)
err := h.execTemplate(rule.Exec, &env)
if err != nil {
log.Warnw("failed to evaluate rule", "instance", msg.Instance, "error", err)
}
}
}
log.Debugw("processed VRRP message", "instance", msg.Instance, "rules", matches)
return nil
}
func (h *VrrpHandler) execTemplate(t *template.Template, env *TemplateEnv) error {
cmdline, err := runTemplate(t, env)
if err != nil {
return err
}
cmd, err := mkCmd(cmdline)
if err != nil {
return err
}
go execRuleCmd(cmd, h.Cxt.Logger)
return nil
}
func (h *VrrpHandler) newTemplateEnv(msg *n.VrrpMessage) TemplateEnv {
return TemplateEnv{
Cxt: h.Config.Context,
Event: MessageEvent{
Type: msg.Type.String(),
State: msg.State.String(),
Instance: msg.Instance,
},
}
}