caddyserver/caddy · error

reading environment file

Error message

reading environment file: %v

What it means

loadEnvFromFile wraps a failed os.Open of the --env-file target. The file could not be opened at all — usually missing or unreadable. (Its sibling 'parsing environment file' fires later, for content problems.) Loaded vars are only set if not already present, so the file is purely supplemental.

Solutions

1. Verify the path exists and is readable by the caddy process user
2. Use an absolute path for --env-file in service units
3. Remember existing environment variables win; you can also set vars directly in the unit instead of the file

Example fix

# before
ExecStart=/usr/bin/caddy run --config /etc/caddy/Caddyfile --env-file .env

# after
ExecStart=/usr/bin/caddy run --config /etc/caddy/Caddyfile --env-file /etc/caddy/.env

# Ensure the env file exists and is readable before launch:
[ -r /etc/caddy/.env ] || { echo "env file missing/unreadable" >&2; exit 1; }
caddy run --config /etc/caddy/Caddyfile --env-file /etc/caddy/.env

When it happens

Trigger: Running 'caddy run --env-file .env' where .env does not exist in the working directory, or the CLI user lacks read permission on it.

Common situations: Deployments copying configs but not the env file; relative path assumptions in service units with a different WorkingDirectory; permissions tightened on secrets files (which is fine — but then grant the caddy user read access).

Related errors

• reading config from file
• backing up current binary
• checking if default Caddyfile exists
• download succeeded, but unable to clean up backup binary
• making folder for CA database

AI-assisted analysis of caddyserver/caddy@50e54ee279 (2026-08-15). Data as JSON: /api/errors/abd33e566f17b793. Report an issue: GitHub.

Appendix: source

Thrown at cmd/main.go:355

// not in the flag set.
func (f Flags) Float64(name string) float64 {
	val, _ := strconv.ParseFloat(f.String(name), 64)
	return val
}

// Duration returns the duration representation of the
// flag given by name. It returns false if the flag
// is not a duration type. It panics if the flag is
// not in the flag set.
func (f Flags) Duration(name string) time.Duration {
	val, _ := caddy.ParseDuration(f.String(name))
	return val
}

func loadEnvFromFile(envFile string) error {
	file, err := os.Open(envFile)
	if err != nil {
		return fmt.Errorf("reading environment file: %v", err)
	}
	defer file.Close()

	envMap, err := parseEnvFile(file)
	if err != nil {
		return fmt.Errorf("parsing environment file: %v", err)
	}

	for k, v := range envMap {
		// do not overwrite existing environment variables
		_, exists := os.LookupEnv(k)
		if !exists {
			if err := os.Setenv(k, v); err != nil {
				return fmt.Errorf("setting environment variables: %v", err)
			}
		}
	}

View on GitHub (pinned to 50e54ee279)