зеркало из https://github.com/microsoft/docker.git
62 строки
1.7 KiB
Go
62 строки
1.7 KiB
Go
package opts
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import (
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"bufio"
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"fmt"
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"os"
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"regexp"
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"strings"
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)
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var (
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// EnvironmentVariableRegexp is a regexp to validate correct environment variables
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// Environment variables set by the user must have a name consisting solely of
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// alphabetics, numerics, and underscores - the first of which must not be numeric.
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EnvironmentVariableRegexp = regexp.MustCompile("^[[:alpha:]_][[:alpha:][:digit:]_]*$")
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)
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// ParseEnvFile reads a file with environment variables enumerated by lines
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func ParseEnvFile(filename string) ([]string, error) {
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fh, err := os.Open(filename)
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if err != nil {
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return []string{}, err
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}
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defer fh.Close()
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lines := []string{}
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scanner := bufio.NewScanner(fh)
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for scanner.Scan() {
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// trim the line from all leading whitespace first
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line := strings.TrimLeft(scanner.Text(), whiteSpaces)
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// line is not empty, and not starting with '#'
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if len(line) > 0 && !strings.HasPrefix(line, "#") {
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data := strings.SplitN(line, "=", 2)
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variable := data[0]
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if !EnvironmentVariableRegexp.MatchString(variable) {
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return []string{}, ErrBadEnvVariable{fmt.Sprintf("variable '%s' is not a valid environment variable", variable)}
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}
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if len(data) > 1 {
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// pass the value through, no trimming
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lines = append(lines, fmt.Sprintf("%s=%s", variable, data[1]))
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} else {
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// if only a pass-through variable is given, clean it up.
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lines = append(lines, fmt.Sprintf("%s=%s", strings.TrimSpace(line), os.Getenv(line)))
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}
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}
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}
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return lines, scanner.Err()
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}
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var whiteSpaces = " \t"
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// ErrBadEnvVariable typed error for bad environment variable
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type ErrBadEnvVariable struct {
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msg string
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}
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func (e ErrBadEnvVariable) Error() string {
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return fmt.Sprintf("poorly formatted environment: %s", e.msg)
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}
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