Env: non-empty GOBIN & GOPATH

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - Lint: use golangci-lint. [4619](https://github.com/beego/beego/pull/4619)
 - Chore: format code. [4615](https://github.com/beego/beego/pull/4615)
+- Env: non-empty GOBIN & GOPATH. [4613](https://github.com/beego/beego/pull/4613)
 - Chore: update dependencies. [4611](https://github.com/beego/beego/pull/4611)
 - Update orm_test.go/TestInsertOrUpdate with table-driven. [4609](https://github.com/beego/beego/pull/4609)
 - Add: Resp() method for web.Controller. [4588](https://github.com/beego/beego/pull/4588)

core/config/env/env.go

@@ -18,7 +18,10 @@ package env
 
 import (
 	"fmt"
+	"go/build"
+	"io/ioutil"
 	"os"
+	"path/filepath"
 	"strings"
 	"sync"
 )
@@ -30,12 +33,14 @@ func init() {
 		splits := strings.Split(e, "=")
 		env.Store(splits[0], os.Getenv(splits[0]))
 	}
+	env.Store("GOBIN", GetGOBIN())   // set non-empty GOBIN when initialization
+	env.Store("GOPATH", GetGOPATH()) // set non-empty GOPATH when initialization
 }
 
 // Get returns a value for a given key.
 // If the key does not exist, the default value will be returned.
 func Get(key string, defVal string) string {
-	if val,ok:= env.Load(key);ok {
+	if val, ok := env.Load(key); ok {
 		return val.(string)
 	}
 	return defVal
@@ -44,7 +49,7 @@ func Get(key string, defVal string) string {
 // MustGet returns a value by key.
 // If the key does not exist, it will return an error.
 func MustGet(key string) (string, error) {
-	if val,ok := env.Load(key); ok{
+	if val, ok := env.Load(key); ok {
 		return val.(string), nil
 	}
 	return "", fmt.Errorf("no env variable with %s", key)
@@ -82,3 +87,91 @@ func GetAll() map[string]string {
 	})
 	return envs
 }
+
+// envFile returns the name of the Go environment configuration file.
+// Copy from https://github.com/golang/go/blob/c4f2a9788a7be04daf931ac54382fbe2cb754938/src/cmd/go/internal/cfg/cfg.go#L150-L166
+func envFile() (string, error) {
+	if file := os.Getenv("GOENV"); file != "" {
+		if file == "off" {
+			return "", fmt.Errorf("GOENV=off")
+		}
+		return file, nil
+	}
+	dir, err := os.UserConfigDir()
+	if err != nil {
+		return "", err
+	}
+	if dir == "" {
+		return "", fmt.Errorf("missing user-config dir")
+	}
+	return filepath.Join(dir, "go", "env"), nil
+}
+
+// GetRuntimeEnv returns the value of runtime environment variable,
+// that is set by running following command: `go env -w key=value`.
+func GetRuntimeEnv(key string) (string, error) {
+	file, err := envFile()
+	if err != nil {
+		return "", err
+	}
+	if file == "" {
+		return "", fmt.Errorf("missing runtime env file")
+	}
+
+	var runtimeEnv string
+	data, err := ioutil.ReadFile(file)
+	if err != nil {
+		return "", err
+	}
+	envStrings := strings.Split(string(data), "\n")
+	for _, envItem := range envStrings {
+		envItem = strings.TrimSuffix(envItem, "\r")
+		envKeyValue := strings.Split(envItem, "=")
+		if len(envKeyValue) == 2 && strings.TrimSpace(envKeyValue[0]) == key {
+			runtimeEnv = strings.TrimSpace(envKeyValue[1])
+		}
+	}
+	return runtimeEnv, nil
+}
+
+// GetGOBIN returns GOBIN environment variable as a string.
+// It will NOT be an empty string.
+func GetGOBIN() string {
+	// The one set by user explicitly by `export GOBIN=/path` or `env GOBIN=/path command`
+	gobin := strings.TrimSpace(Get("GOBIN", ""))
+	if gobin == "" {
+		var err error
+		// The one set by user by running `go env -w GOBIN=/path`
+		gobin, err = GetRuntimeEnv("GOBIN")
+		if err != nil {
+			// The default one that Golang uses
+			return filepath.Join(build.Default.GOPATH, "bin")
+		}
+		if gobin == "" {
+			return filepath.Join(build.Default.GOPATH, "bin")
+		}
+		return gobin
+	}
+	return gobin
+}
+
+// GetGOPATH returns GOPATH environment variable as a string.
+// It will NOT be an empty string.
+func GetGOPATH() string {
+	// The one set by user explicitly by `export GOPATH=/path` or `env GOPATH=/path command`
+	gopath := strings.TrimSpace(Get("GOPATH", ""))
+	if gopath == "" {
+		var err error
+		// The one set by user by running `go env -w GOPATH=/path`
+		gopath, err = GetRuntimeEnv("GOPATH")
+		if err != nil {
+			// The default one that Golang uses
+			return build.Default.GOPATH
+		}
+		if gopath == "" {
+			return build.Default.GOPATH
+		}
+		return gopath
+	}
+	return gopath
+}

core/config/env/env_test.go

@@ -15,7 +15,9 @@
 package env
 
 import (
+	"go/build"
 	"os"
+	"path/filepath"
 	"testing"
 )
 
@@ -73,3 +75,41 @@ func TestEnvGetAll(t *testing.T) {
 		t.Error("expected environment not empty.")
 	}
 }
+
+func TestEnvFile(t *testing.T) {
+	envFile, err := envFile()
+	if err != nil {
+		t.Errorf("expected to get env file without error, but got %s.", err)
+	}
+	if envFile == "" {
+		t.Error("expected to get valid env file, but got empty string.")
+	}
+}
+
+func TestGetGOBIN(t *testing.T) {
+	customGOBIN := filepath.Join("path", "to", "gobin")
+	Set("GOBIN", customGOBIN)
+	if gobin := GetGOBIN(); gobin != Get("GOBIN", "") {
+		t.Errorf("expected GOBIN environment variable equals to %s, but got %s.", customGOBIN, gobin)
+	}
+
+	Set("GOBIN", "")
+	defaultGOBIN := filepath.Join(build.Default.GOPATH, "bin")
+	if gobin := GetGOBIN(); gobin != defaultGOBIN {
+		t.Errorf("expected GOBIN environment variable equals to %s, but got %s.", defaultGOBIN, gobin)
+	}
+}
+
+func TestGetGOPATH(t *testing.T) {
+	customGOPATH := filepath.Join("path", "to", "gopath")
+	Set("GOPATH", customGOPATH)
+	if goPath := GetGOPATH(); goPath != Get("GOPATH", "") {
+		t.Errorf("expected GOPATH environment variable equals to %s, but got %s.", customGOPATH, goPath)
+	}
+
+	Set("GOPATH", "")
+	defaultGOPATH := build.Default.GOPATH
+	if goPath := GetGOPATH(); goPath != defaultGOPATH {
+		t.Errorf("expected GOPATH environment variable equals to %s, but got %s.", defaultGOPATH, goPath)
+	}
+}