DockerCLI/opts/envfile.go

55 lines
1.3 KiB
Go

package opts
import (
"bufio"
"fmt"
"os"
"strings"
)
/*
Read in a line delimited file with environment variables enumerated
*/
func ParseEnvFile(filename string) ([]string, error) {
fh, err := os.Open(filename)
if err != nil {
return []string{}, err
}
defer fh.Close()
lines := []string{}
scanner := bufio.NewScanner(fh)
for scanner.Scan() {
line := scanner.Text()
// line is not empty, and not starting with '#'
if len(line) > 0 && !strings.HasPrefix(line, "#") {
if strings.Contains(line, "=") {
data := strings.SplitN(line, "=", 2)
// trim the front of a variable, but nothing else
variable := strings.TrimLeft(data[0], whiteSpaces)
if strings.ContainsAny(variable, whiteSpaces) {
return []string{}, ErrBadEnvVariable{fmt.Sprintf("variable '%s' has white spaces", variable)}
}
// pass the value through, no trimming
lines = append(lines, fmt.Sprintf("%s=%s", variable, data[1]))
} else {
// if only a pass-through variable is given, clean it up.
lines = append(lines, fmt.Sprintf("%s=%s", strings.TrimSpace(line), os.Getenv(line)))
}
}
}
return lines, nil
}
var whiteSpaces = " \t"
type ErrBadEnvVariable struct {
msg string
}
func (e ErrBadEnvVariable) Error() string {
return fmt.Sprintf("poorly formatted environment: %s", e.msg)
}