WIP: added fallback env

cmd/wingmate/bridge.go

@@ -32,7 +32,7 @@ func convert(cfg *config.Config) *wConfig {
 
 	for _, s := range cfg.Service {
 		st := task.NewServiceTask(s.Name).SetCommand(s.Command...).SetEnv(s.Environ...)
-		st.SetFlagSetsid(s.Setsid).SetWorkingDir(s.WorkingDir)
+		st.SetFallbackEnv(s.FallbackEnv...).SetFlagSetsid(s.Setsid).SetWorkingDir(s.WorkingDir)
 		st.SetUser(s.User).SetGroup(s.Group).SetStartSecs(s.StartSecs).SetPidFile(s.PidFile)
 		st.SetConfig(cfg)
 		retval.tasks.AddService(st)
@@ -52,7 +52,8 @@ func convert(cfg *config.Config) *wConfig {
 		schedule = configToTaskCronSchedule(c.CronSchedule)
 
 		ct := task.NewCronTask(c.Name).SetCommand(c.Command...).SetEnv(c.Environ...)
-		ct.SetFlagSetsid(c.Setsid).SetWorkingDir(c.WorkingDir).SetUser(c.User).SetGroup(c.Group)
+		ct.SetFallbackEnv(c.FallbackEnv...).SetFlagSetsid(c.Setsid).SetWorkingDir(c.WorkingDir)
+		ct.SetUser(c.User).SetGroup(c.Group)
 		ct.SetSchedule(c.Schedule, schedule)
 		ct.SetConfig(cfg)
 

config/config.go

@@ -44,6 +44,7 @@ type Config struct {
 type Task struct {
 	Command     []string `mapstructure:"command"`
 	Environ     []string `mapstructure:"environ"`
+	FallbackEnv []string `mapstructure:"fallback_env"`
 	Setsid      bool     `mapstructure:"setsid"`
 	User        string   `mapstructure:"user"`
 	Group       string   `mapstructure:"group"`

task/cron.go

@@ -81,6 +81,7 @@ type CronTask struct {
 	command            []string
 	cmdLine            []string
 	environ            []string
+	fallbackEnv        []string
 	setsid             bool
 	workingDir         string
 	lastRun            time.Time
@@ -107,6 +108,12 @@ func (c *CronTask) SetEnv(envs ...string) *CronTask {
 	return c
 }
 
+func (c *CronTask) SetFallbackEnv(envs ...string) *CronTask {
+	c.fallbackEnv = make([]string, len(envs))
+	copy(c.fallbackEnv, envs)
+	return c
+}
+
 func (c *CronTask) SetFlagSetsid(flag bool) *CronTask {
 	c.setsid = flag
 	return c
@@ -257,7 +264,8 @@ func (c *CronTask) Environ() []string {
 }
 
 func (c *CronTask) PatchEnv(env []string) []string {
-	return wmenv.PatchEnv(env, c.environ)
+	env = wmenv.PatchEnv(env, c.environ)
+	return wmenv.FallbackEnv(env, c.fallbackEnv)
 }
 
 func (c *CronTask) Setsid() bool {

task/env/env.go

@@ -95,3 +95,33 @@ func ExpandEnv(env []string, input []string) []string {
 	}
 	return input
 }
+
+func FallbackEnv(env []string, fallbacks []string) []string {
+	envMap := make(map[string]string)
+	for _, e := range env {
+		key, value, ok := strings.Cut(e, "=")
+		if !ok {
+			wingmate.Log().Warn().Msgf("removing bad environment:", e)
+			continue
+		}
+		envMap[key] = value
+	}
+
+	for _, e := range fallbacks {
+		key, value, ok := strings.Cut(e, "=")
+		if !ok {
+			wingmate.Log().Warn().Msgf("removing bad environment:", e)
+			continue
+		}
+
+		value = envCapture.ReplaceAllStringFunc(value, func(rep string) string {
+			return expandEnv(envMap, rep)
+		})
+
+		if _, ok = envMap[key]; !ok {
+			env = append(env, fmt.Sprintf("%s=%s", key, value))
+		}
+	}
+
+	return env
+}

task/task.go

@@ -76,6 +76,7 @@ type ServiceTask struct {
 	command     []string
 	cmdLine     []string
 	environ     []string
+	fallbackEnv []string
 	setsid      bool
 	background  bool
 	workingDir  string
@@ -103,6 +104,12 @@ func (t *ServiceTask) SetEnv(envs ...string) *ServiceTask {
 	return t
 }
 
+func (t *ServiceTask) SetFallbackEnv(envs ...string) *ServiceTask {
+	t.fallbackEnv = make([]string, len(envs))
+	copy(t.fallbackEnv, envs)
+	return t
+}
+
 func (t *ServiceTask) SetFlagSetsid(flag bool) *ServiceTask {
 	t.setsid = flag
 	return t
@@ -311,7 +318,8 @@ func (t *ServiceTask) Environ() []string {
 }
 
 func (t *ServiceTask) PatchEnv(env []string) []string {
-	return wmenv.PatchEnv(env, t.environ)
+	env = wmenv.PatchEnv(env, t.environ)
+	return wmenv.FallbackEnv(env, t.fallbackEnv)
 }
 
 func (t *ServiceTask) Setsid() bool {