Env vars set in conf.d files are expected to propagate

cmd/backup/config_provider.go

@@ -49,8 +49,9 @@ func loadEnvVars() (*Config, error) {
 }
 
 type configFile struct {
-	name   string
-	config *Config
+	name              string
+	config            *Config
+	additionalEnvVars map[string]string
 }
 
 func loadEnvFiles(directory string) ([]configFile, error) {
@@ -74,13 +75,16 @@ func loadEnvFiles(directory string) ([]configFile, error) {
 		}
 		lookup := func(key string) (string, bool) {
 			val, ok := envFile[key]
-			return val, ok
+			if ok {
+				return val, ok
+			}
+			return os.LookupEnv(key)
 		}
 		c, err := loadConfig(lookup)
 		if err != nil {
 			return nil, fmt.Errorf("loadEnvFiles: error loading config from file %s: %w", p, err)
 		}
-		cs = append(cs, configFile{config: c, name: item.Name()})
+		cs = append(cs, configFile{config: c, name: item.Name(), additionalEnvVars: envFile})
 	}
 
 	return cs, nil

cmd/backup/main.go

@@ -36,7 +36,7 @@ func (c *command) must(err error) {
 	}
 }
 
-func runScript(c *Config) (err error) {
+func runScript(c *Config, envVars map[string]string) (err error) {
 	defer func() {
 		if derr := recover(); derr != nil {
 			err = fmt.Errorf("runScript: unexpected panic running script: %v", err)
@@ -63,6 +63,35 @@ func runScript(c *Config) (err error) {
 			}
 		}()
 
+		if envVars != nil {
+			for key, value := range envVars {
+				currentVal, currentOk := os.LookupEnv(key)
+				defer func(currentKey, currentVal string, currentOk bool) {
+					if !currentOk {
+						_ = os.Unsetenv(currentKey)
+					} else {
+						_ = os.Setenv(currentKey, currentVal)
+					}
+					s.logger.Info(fmt.Sprintf("unset %v: %v", currentKey, currentVal))
+				}(key, currentVal, currentOk)
+
+				if err := os.Setenv(key, value); err != nil {
+					return fmt.Errorf(
+						"Unexpected error overloading environment %s: %w",
+						s.c.BackupCronExpression,
+						err,
+					)
+				}
+				s.logger.Info(fmt.Sprintf("set %v: %v", key, value))
+			}
+		}
+
+		if s.c.BackupFilenameExpand {
+			s.file = os.ExpandEnv(s.file)
+			s.c.BackupLatestSymlink = os.ExpandEnv(s.c.BackupLatestSymlink)
+			s.c.BackupPruningPrefix = os.ExpandEnv(s.c.BackupPruningPrefix)
+		}
+
 		scriptErr := func() error {
 			if err := s.withLabeledCommands(lifecyclePhaseArchive, func() (err error) {
 				restartContainersAndServices, err := s.stopContainersAndServices()
@@ -132,15 +161,16 @@ func (c *command) runInForeground(profileCronExpression string) error {
 		),
 	)
 
-	addJob := func(config *Config, name string) error {
+	addJob := func(config *Config, name string, envVars map[string]string) error {
 		if _, err := cr.AddFunc(config.BackupCronExpression, func() {
 			c.logger.Info(
 				fmt.Sprintf(
 					"Now running script on schedule %s",
 					config.BackupCronExpression,
 				),
 			)
-			if err := runScript(config); err != nil {
+
+			if err := runScript(config, envVars); err != nil {
 				c.logger.Error(
 					fmt.Sprintf(
 						"Unexpected error running schedule %s: %v",
@@ -175,15 +205,15 @@ func (c *command) runInForeground(profileCronExpression string) error {
 		if err != nil {
 			return fmt.Errorf("runInForeground: could not load config from environment variables: %w", err)
 		} else {
-			err = addJob(c, "from environment")
+			err = addJob(c, "from environment", nil)
 			if err != nil {
 				return fmt.Errorf("runInForeground: error adding job from env: %w", err)
 			}
 		}
 	} else {
 		c.logger.Info("/etc/dockervolumebackup/conf.d was found, using configuration files from this directory.")
 		for _, config := range cs {
-			err = addJob(config.config, config.name)
+			err = addJob(config.config, config.name, config.additionalEnvVars)
 			if err != nil {
 				return fmt.Errorf("runInForeground: error adding jobs from conf files: %w", err)
 			}
@@ -227,7 +257,7 @@ func (c *command) runAsCommand() error {
 	if err != nil {
 		return fmt.Errorf("runAsCommand: error loading env vars: %w", err)
 	}
-	err = runScript(config)
+	err = runScript(config, nil)
 	if err != nil {
 		return fmt.Errorf("runAsCommand: error running script: %w", err)
 	}

cmd/backup/script.go

@@ -97,11 +97,6 @@ func newScript(c *Config) (*script, error) {
 	}
 	s.file = bf.String()
 
-	if s.c.BackupFilenameExpand {
-		s.file = os.ExpandEnv(s.file)
-		s.c.BackupLatestSymlink = os.ExpandEnv(s.c.BackupLatestSymlink)
-		s.c.BackupPruningPrefix = os.ExpandEnv(s.c.BackupPruningPrefix)
-	}
 	s.file = timeutil.Strftime(&s.stats.StartTime, s.file)
 
 	_, err := os.Stat("/var/run/docker.sock")

test/confd/01backup.env

@@ -1,2 +1,2 @@
-BACKUP_CRON_EXPRESSION="*/1 * * * *"
 NAME="conf"
+BACKUP_CRON_EXPRESSION="*/1 * * * *"