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/*
package envy makes working with ENV variables in Go trivial.
* Get ENV variables with default values.
* Set ENV variables safely without affecting the underlying system.
* Temporarily change ENV vars; useful for testing.
* Map all of the key/values in the ENV.
* Loads .env files (by using [godotenv](https://github.com/joho/godotenv/))
* More!
*/
package envy
import (
"errors"
"flag"
"fmt"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"runtime"
"strings"
"sync"
"github.com/joho/godotenv"
"github.com/rogpeppe/go-internal/modfile"
)
var gil = &sync.RWMutex{}
var env = map[string]string{}
// GO111MODULE is ENV for turning mods on/off
const GO111MODULE = "GO111MODULE"
func init() {
Load()
loadEnv()
}
// Load the ENV variables to the env map
func loadEnv() {
gil.Lock()
defer gil.Unlock()
if os.Getenv("GO_ENV") == "" {
// if the flag "test.v" is *defined*, we're running as a unit test. Note that we don't care
// about v.Value (verbose test mode); we just want to know if the test environment has defined
// it. It's also possible that the flags are not yet fully parsed (i.e. flag.Parsed() == false),
// so we could not depend on v.Value anyway.
//
if v := flag.Lookup("test.v"); v != nil {
env["GO_ENV"] = "test"
}
}
// set the GOPATH if using >= 1.8 and the GOPATH isn't set
if os.Getenv("GOPATH") == "" {
out, err := exec.Command("go", "env", "GOPATH").Output()
if err == nil {
gp := strings.TrimSpace(string(out))
os.Setenv("GOPATH", gp)
}
}
for _, e := range os.Environ() {
pair := strings.Split(e, "=")
env[pair[0]] = os.Getenv(pair[0])
}
}
// Mods returns true if module support is enabled, false otherwise
// See https://github.com/golang/go/wiki/Modules#how-to-install-and-activate-module-support for details
func Mods() bool {
go111 := Get(GO111MODULE, "")
if !InGoPath() {
return go111 != "off"
}
return go111 == "on"
}
// Reload the ENV variables. Useful if
// an external ENV manager has been used
func Reload() {
env = map[string]string{}
loadEnv()
}
// Load .env files. Files will be loaded in the same order that are received.
// Redefined vars will override previously existing values.
// IE: envy.Load(".env", "test_env/.env") will result in DIR=test_env
// If no arg passed, it will try to load a .env file.
func Load(files ...string) error {
// If no files received, load the default one
if len(files) == 0 {
err := godotenv.Overload()
if err == nil {
Reload()
}
return err
}
// We received a list of files
for _, file := range files {
// Check if it exists or we can access
if _, err := os.Stat(file); err != nil {
// It does not exist or we can not access.
// Return and stop loading
return err
}
// It exists and we have permission. Load it
if err := godotenv.Overload(file); err != nil {
return err
}
// Reload the env so all new changes are noticed
Reload()
}
return nil
}
// Get a value from the ENV. If it doesn't exist the
// default value will be returned.
func Get(key string, value string) string {
gil.RLock()
defer gil.RUnlock()
if v, ok := env[key]; ok {
return v
}
return value
}
// Get a value from the ENV. If it doesn't exist
// an error will be returned
func MustGet(key string) (string, error) {
gil.RLock()
defer gil.RUnlock()
if v, ok := env[key]; ok {
return v, nil
}
return "", fmt.Errorf("could not find ENV var with %s", key)
}
// Set a value into the ENV. This is NOT permanent. It will
// only affect values accessed through envy.
func Set(key string, value string) {
gil.Lock()
defer gil.Unlock()
env[key] = value
}
// MustSet the value into the underlying ENV, as well as envy.
// This may return an error if there is a problem setting the
// underlying ENV value.
func MustSet(key string, value string) error {
gil.Lock()
defer gil.Unlock()
err := os.Setenv(key, value)
if err != nil {
return err
}
env[key] = value
return nil
}
// Map all of the keys/values set in envy.
func Map() map[string]string {
gil.RLock()
defer gil.RUnlock()
cp := map[string]string{}
for k, v := range env {
cp[k] = v
}
return cp
}
// Temp makes a copy of the values and allows operation on
// those values temporarily during the run of the function.
// At the end of the function run the copy is discarded and
// the original values are replaced. This is useful for testing.
// Warning: This function is NOT safe to use from a goroutine or
// from code which may access any Get or Set function from a goroutine
func Temp(f func()) {
oenv := env
env = map[string]string{}
for k, v := range oenv {
env[k] = v
}
defer func() { env = oenv }()
f()
}
func GoPath() string {
return Get("GOPATH", "")
}
func GoBin() string {
return Get("GO_BIN", "go")
}
func InGoPath() bool {
pwd, _ := os.Getwd()
for _, p := range GoPaths() {
if strings.HasPrefix(pwd, p) {
return true
}
}
return false
}
// GoPaths returns all possible GOPATHS that are set.
func GoPaths() []string {
gp := Get("GOPATH", "")
if runtime.GOOS == "windows" {
return strings.Split(gp, ";") // Windows uses a different separator
}
return strings.Split(gp, ":")
}
func importPath(path string) string {
path = strings.TrimPrefix(path, "/private")
for _, gopath := range GoPaths() {
srcpath := filepath.Join(gopath, "src")
rel, err := filepath.Rel(srcpath, path)
if err == nil {
return filepath.ToSlash(rel)
}
}
// fallback to trim
rel := strings.TrimPrefix(path, filepath.Join(GoPath(), "src"))
rel = strings.TrimPrefix(rel, string(filepath.Separator))
return filepath.ToSlash(rel)
}
// CurrentModule will attempt to return the module name from `go.mod` if
// modules are enabled.
// If modules are not enabled it will fallback to using CurrentPackage instead.
func CurrentModule() (string, error) {
if !Mods() {
return CurrentPackage(), nil
}
moddata, err := ioutil.ReadFile("go.mod")
if err != nil {
return "", errors.New("go.mod cannot be read or does not exist while go module is enabled")
}
packagePath := modfile.ModulePath(moddata)
if packagePath == "" {
return "", errors.New("go.mod is malformed")
}
return packagePath, nil
}
// CurrentPackage attempts to figure out the current package name from the PWD
// Use CurrentModule for a more accurate package name.
func CurrentPackage() string {
if Mods() {
}
pwd, _ := os.Getwd()
return importPath(pwd)
}
func Environ() []string {
gil.RLock()
defer gil.RUnlock()
var e []string
for k, v := range env {
e = append(e, fmt.Sprintf("%s=%s", k, v))
}
return e
}
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