Fix use env vars when exec

env.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+)
+
+var (
+	preloadEnvVars map[string]struct{} = map[string]struct{}{
+		"SHELL": struct{}{},
+		"PWD": struct{}{},
+		"LOGNAME": struct{}{},
+		"HOME": struct{}{},
+		"LANG": struct{}{},
+		"USER": struct{}{},
+		"SHLVL": struct{}{},
+		"MAILTO": struct{}{},
+		"LC_ALL": struct{}{},
+		"PATH": struct{}{},
+		"_": struct{}{},
+	}
+	reservedEnvVars []string = []string{"LOGNAME", "USER"}
+)
+
+type CronEnvs struct {
+	envMap map[string]string
+}
+
+func NewCronEnvs(parentEnvs []string) *CronEnvs {
+	pEnvs := make(map[string]string)
+	for _, e := range parentEnvs {
+		splitAt := strings.Index(e, "=")
+		key := e[:splitAt]
+		if _, ok := preloadEnvVars[key]; ok {
+			pEnvs[key] = e[splitAt+1:]
+		}
+	}
+
+	return &CronEnvs{
+		envMap: pEnvs,
+	}
+}
+
+func (e *CronEnvs) SetEnv(key, value string) {
+	e.envMap[key] = value
+}
+
+func (e *CronEnvs) GetEnv(key string) string {
+	if value, ok := e.envMap[key]; ok {
+		return value
+	} else {
+		return ""
+	}
+}
+
+func (e *CronEnvs) UpdateEnvForJob(c *CrontabEntry) error {
+	for _, envStr := range c.Env {
+		splitAt := strings.Index(envStr, "=")
+		key := envStr[:splitAt]
+		for _, env := range reservedEnvVars {
+			if env == key {
+				return fmt.Errorf("User can't set env %s", key)
+			}
+		}
+		e.envMap[key] = envStr[splitAt+1:]	
+	}
+	return nil
+}
+
+func (e *CronEnvs) GetEnvList() []string {
+	result := []string{}
+	for k, v := range e.envMap {
+		result = append(result, fmt.Sprintf("%s=%s", k, v))
+	}
+	return result
+}
+

runner.go

@@ -47,7 +47,7 @@ func (r *Runner) Add(cronjob CrontabEntry) error {
 		cronjob.SetEntryId(eid)
 		r.cronjobs[eid] = &cronjob
 		prometheusMetricTask.With(r.cronjobToPrometheusLabels(cronjob)).Set(1)
-		log.WithFields(LogCronjobToFields(cronjob)).Infof("cronjob added")
+		log.WithFields(LogCronjobToFields(cronjob)).Infof("cronjob added without user switch")
 	}
 
 	return err
@@ -80,6 +80,22 @@ func (r *Runner) AddWithUser(cronjob CrontabEntry) error {
 			return false
 		}
 
+		// update user env
+		envs := NewCronEnvs(execCmd.Env)
+		envs.SetEnv("LOGNAME", cronjob.User)
+		envs.SetEnv("USER", cronjob.User)
+		if u.HomeDir != "" {
+			envs.SetEnv("HOME", u.HomeDir)
+			envs.SetEnv("PWD", u.HomeDir)
+			execCmd.Dir = u.HomeDir
+		}
+		err = envs.UpdateEnvForJob(&cronjob)
+		if err != nil {
+			log.WithFields(LogCronjobToFields(cronjob)).Errorf("Cannot override env vars: %v", err)
+			return false
+		}
+		execCmd.Env = envs.GetEnvList()
+
 		// add process credentials
 		execCmd.SysProcAttr = &syscall.SysProcAttr{}
 		execCmd.SysProcAttr.Credential = &syscall.Credential{Uid: uint32(userId), Gid: uint32(groupId)}
@@ -93,7 +109,7 @@ func (r *Runner) AddWithUser(cronjob CrontabEntry) error {
 		cronjob.SetEntryId(eid)
 		r.cronjobs[eid] = &cronjob
 		prometheusMetricTask.With(r.cronjobToPrometheusLabels(cronjob)).Set(1)
-		log.WithFields(LogCronjobToFields(cronjob)).Infof("cronjob added")
+		log.WithFields(LogCronjobToFields(cronjob)).Infof("cronjob added with user")
 	}
 
 	return err