service/vendor/github.com/subosito/gotenv/gotenv.go

410 lines
10 KiB
Go

// Package gotenv provides functionality to dynamically load the environment variables
package gotenv
import (
"bufio"
"bytes"
"fmt"
"io"
"os"
"path/filepath"
"regexp"
"sort"
"strconv"
"strings"
"golang.org/x/text/encoding/unicode"
"golang.org/x/text/transform"
)
const (
// Pattern for detecting valid line format
linePattern = `\A\s*(?:export\s+)?([\w\.]+)(?:\s*=\s*|:\s+?)('(?:\'|[^'])*'|"(?:\"|[^"])*"|[^#\n]+)?\s*(?:\s*\#.*)?\z`
// Pattern for detecting valid variable within a value
variablePattern = `(\\)?(\$)(\{?([A-Z0-9_]+)?\}?)`
)
// Byte order mark character
var (
bomUTF8 = []byte("\xEF\xBB\xBF")
bomUTF16LE = []byte("\xFF\xFE")
bomUTF16BE = []byte("\xFE\xFF")
)
// Env holds key/value pair of valid environment variable
type Env map[string]string
// Load is a function to load a file or multiple files and then export the valid variables into environment variables if they do not exist.
// When it's called with no argument, it will load `.env` file on the current path and set the environment variables.
// Otherwise, it will loop over the filenames parameter and set the proper environment variables.
func Load(filenames ...string) error {
return loadenv(false, filenames...)
}
// OverLoad is a function to load a file or multiple files and then export and override the valid variables into environment variables.
func OverLoad(filenames ...string) error {
return loadenv(true, filenames...)
}
// Must is wrapper function that will panic when supplied function returns an error.
func Must(fn func(filenames ...string) error, filenames ...string) {
if err := fn(filenames...); err != nil {
panic(err.Error())
}
}
// Apply is a function to load an io Reader then export the valid variables into environment variables if they do not exist.
func Apply(r io.Reader) error {
return parset(r, false)
}
// OverApply is a function to load an io Reader then export and override the valid variables into environment variables.
func OverApply(r io.Reader) error {
return parset(r, true)
}
func loadenv(override bool, filenames ...string) error {
if len(filenames) == 0 {
filenames = []string{".env"}
}
for _, filename := range filenames {
f, err := os.Open(filename)
if err != nil {
return err
}
err = parset(f, override)
f.Close()
if err != nil {
return err
}
}
return nil
}
// parse and set :)
func parset(r io.Reader, override bool) error {
env, err := strictParse(r, override)
if err != nil {
return err
}
for key, val := range env {
setenv(key, val, override)
}
return nil
}
func setenv(key, val string, override bool) {
if override {
os.Setenv(key, val)
} else {
if _, present := os.LookupEnv(key); !present {
os.Setenv(key, val)
}
}
}
// Parse is a function to parse line by line any io.Reader supplied and returns the valid Env key/value pair of valid variables.
// It expands the value of a variable from the environment variable but does not set the value to the environment itself.
// This function is skipping any invalid lines and only processing the valid one.
func Parse(r io.Reader) Env {
env, _ := strictParse(r, false)
return env
}
// StrictParse is a function to parse line by line any io.Reader supplied and returns the valid Env key/value pair of valid variables.
// It expands the value of a variable from the environment variable but does not set the value to the environment itself.
// This function is returning an error if there are any invalid lines.
func StrictParse(r io.Reader) (Env, error) {
return strictParse(r, false)
}
// Read is a function to parse a file line by line and returns the valid Env key/value pair of valid variables.
// It expands the value of a variable from the environment variable but does not set the value to the environment itself.
// This function is skipping any invalid lines and only processing the valid one.
func Read(filename string) (Env, error) {
f, err := os.Open(filename)
if err != nil {
return nil, err
}
defer f.Close()
return strictParse(f, false)
}
// Unmarshal reads a string line by line and returns the valid Env key/value pair of valid variables.
// It expands the value of a variable from the environment variable but does not set the value to the environment itself.
// This function is returning an error if there are any invalid lines.
func Unmarshal(str string) (Env, error) {
return strictParse(strings.NewReader(str), false)
}
// Marshal outputs the given environment as a env file.
// Variables will be sorted by name.
func Marshal(env Env) (string, error) {
lines := make([]string, 0, len(env))
for k, v := range env {
if d, err := strconv.Atoi(v); err == nil {
lines = append(lines, fmt.Sprintf(`%s=%d`, k, d))
} else {
lines = append(lines, fmt.Sprintf(`%s=%q`, k, v))
}
}
sort.Strings(lines)
return strings.Join(lines, "\n"), nil
}
// Write serializes the given environment and writes it to a file
func Write(env Env, filename string) error {
content, err := Marshal(env)
if err != nil {
return err
}
// ensure the path exists
if err := os.MkdirAll(filepath.Dir(filename), 0o775); err != nil {
return err
}
// create or truncate the file
file, err := os.Create(filename)
if err != nil {
return err
}
defer file.Close()
_, err = file.WriteString(content + "\n")
if err != nil {
return err
}
return file.Sync()
}
// splitLines is a valid SplitFunc for a bufio.Scanner. It will split lines on CR ('\r'), LF ('\n') or CRLF (any of the three sequences).
// If a CR is immediately followed by a LF, it is treated as a CRLF (one single line break).
func splitLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
if atEOF && len(data) == 0 {
return 0, nil, bufio.ErrFinalToken
}
idx := bytes.IndexAny(data, "\r\n")
switch {
case atEOF && idx < 0:
return len(data), data, bufio.ErrFinalToken
case idx < 0:
return 0, nil, nil
}
// consume CR or LF
eol := idx + 1
// detect CRLF
if len(data) > eol && data[eol-1] == '\r' && data[eol] == '\n' {
eol++
}
return eol, data[:idx], nil
}
func strictParse(r io.Reader, override bool) (Env, error) {
env := make(Env)
buf := new(bytes.Buffer)
tee := io.TeeReader(r, buf)
// There can be a maximum of 3 BOM bytes.
bomByteBuffer := make([]byte, 3)
_, err := tee.Read(bomByteBuffer)
if err != nil && err != io.EOF {
return env, err
}
z := io.MultiReader(buf, r)
// We chooes a different scanner depending on file encoding.
var scanner *bufio.Scanner
if bytes.HasPrefix(bomByteBuffer, bomUTF8) {
scanner = bufio.NewScanner(transform.NewReader(z, unicode.UTF8BOM.NewDecoder()))
} else if bytes.HasPrefix(bomByteBuffer, bomUTF16LE) {
scanner = bufio.NewScanner(transform.NewReader(z, unicode.UTF16(unicode.LittleEndian, unicode.ExpectBOM).NewDecoder()))
} else if bytes.HasPrefix(bomByteBuffer, bomUTF16BE) {
scanner = bufio.NewScanner(transform.NewReader(z, unicode.UTF16(unicode.BigEndian, unicode.ExpectBOM).NewDecoder()))
} else {
scanner = bufio.NewScanner(z)
}
scanner.Split(splitLines)
for scanner.Scan() {
if err := scanner.Err(); err != nil {
return env, err
}
line := strings.TrimSpace(scanner.Text())
if line == "" || line[0] == '#' {
continue
}
quote := ""
// look for the delimiter character
idx := strings.Index(line, "=")
if idx == -1 {
idx = strings.Index(line, ":")
}
// look for a quote character
if idx > 0 && idx < len(line)-1 {
val := strings.TrimSpace(line[idx+1:])
if val[0] == '"' || val[0] == '\'' {
quote = val[:1]
// look for the closing quote character within the same line
idx = strings.LastIndex(strings.TrimSpace(val[1:]), quote)
if idx >= 0 && val[idx] != '\\' {
quote = ""
}
}
}
// look for the closing quote character
for quote != "" && scanner.Scan() {
l := scanner.Text()
line += "\n" + l
idx := strings.LastIndex(l, quote)
if idx > 0 && l[idx-1] == '\\' {
// foud a matching quote character but it's escaped
continue
}
if idx >= 0 {
// foud a matching quote
quote = ""
}
}
if quote != "" {
return env, fmt.Errorf("missing quotes")
}
err := parseLine(line, env, override)
if err != nil {
return env, err
}
}
return env, scanner.Err()
}
var (
lineRgx = regexp.MustCompile(linePattern)
unescapeRgx = regexp.MustCompile(`\\([^$])`)
varRgx = regexp.MustCompile(variablePattern)
)
func parseLine(s string, env Env, override bool) error {
rm := lineRgx.FindStringSubmatch(s)
if len(rm) == 0 {
return checkFormat(s, env)
}
key := strings.TrimSpace(rm[1])
val := strings.TrimSpace(rm[2])
var hsq, hdq bool
// check if the value is quoted
if l := len(val); l >= 2 {
l -= 1
// has double quotes
hdq = val[0] == '"' && val[l] == '"'
// has single quotes
hsq = val[0] == '\'' && val[l] == '\''
// remove quotes '' or ""
if hsq || hdq {
val = val[1:l]
}
}
if hdq {
val = strings.ReplaceAll(val, `\n`, "\n")
val = strings.ReplaceAll(val, `\r`, "\r")
// Unescape all characters except $ so variables can be escaped properly
val = unescapeRgx.ReplaceAllString(val, "$1")
}
if !hsq {
fv := func(s string) string {
return varReplacement(s, hsq, env, override)
}
val = varRgx.ReplaceAllStringFunc(val, fv)
}
env[key] = val
return nil
}
func parseExport(st string, env Env) error {
if strings.HasPrefix(st, "export") {
vs := strings.SplitN(st, " ", 2)
if len(vs) > 1 {
if _, ok := env[vs[1]]; !ok {
return fmt.Errorf("line `%s` has an unset variable", st)
}
}
}
return nil
}
var varNameRgx = regexp.MustCompile(`(\$)(\{?([A-Z0-9_]+)\}?)`)
func varReplacement(s string, hsq bool, env Env, override bool) string {
if s == "" {
return s
}
if s[0] == '\\' {
// the dollar sign is escaped
return s[1:]
}
if hsq {
return s
}
mn := varNameRgx.FindStringSubmatch(s)
if len(mn) == 0 {
return s
}
v := mn[3]
if replace, ok := os.LookupEnv(v); ok && !override {
return replace
}
if replace, ok := env[v]; ok {
return replace
}
return os.Getenv(v)
}
func checkFormat(s string, env Env) error {
st := strings.TrimSpace(s)
if st == "" || st[0] == '#' {
return nil
}
if err := parseExport(st, env); err != nil {
return err
}
return fmt.Errorf("line `%s` doesn't match format", s)
}