decompose GOPATH and set it according to the current working dir. (#712)

* decompose GOPATH and set it according to the current working dir.

there are different places in the project where the value of env var GOPATH is used,
and cannot handle composed GOPATHs. this will determine the correct GOPATH
based on the current workin dir and set it during the execution.

* get rid of restoreGopath and move the GOPATH check in GetGopath

restoreGopath is not required, as SetEnv doesn't affect the parent process's enviroment

Author: nrobert13

commands/operator-sdk/main.go

@@ -19,9 +19,13 @@ import (
 	"os"
 
 	"github.com/operator-framework/operator-sdk/commands/operator-sdk/cmd"
+	"github.com/operator-framework/operator-sdk/internal/util/projutil"
 )
 
 func main() {
+	gopath := projutil.GetGopath()
+	projutil.SetGopath(gopath)
+
 	if err := cmd.NewRootCmd().Execute(); err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(-1)

internal/util/projutil/project_util.go

@@ -75,23 +75,8 @@ func MustGetwd() string {
 // e.g: "github.com/example-inc/app-operator"
 func CheckAndGetCurrPkg() string {
 	gopath := os.Getenv(GopathEnv)
-	if len(gopath) == 0 {
-		log.Fatalf("get current pkg failed: GOPATH env not set")
-	}
-	var goSrc string
-	cwdInGopath := false
+	goSrc := filepath.Join(gopath, SrcDir)
 	wd := MustGetwd()
-	for _, path := range strings.Split(gopath, ":") {
-		goSrc = filepath.Join(path, SrcDir)
-
-		if strings.HasPrefix(filepath.Dir(wd), goSrc) {
-			cwdInGopath = true
-			break
-		}
-	}
-	if !cwdInGopath {
-		log.Fatalf("check current pkg failed: must run from gopath")
-	}
 	currPkg := strings.Replace(wd, goSrc+string(filepath.Separator), "", 1)
 	// strip any "/" prefix from the repo path.
 	return strings.TrimPrefix(currPkg, string(filepath.Separator))
@@ -108,3 +93,27 @@ func GetOperatorType() OperatorType {
 	}
 	return OperatorTypeGo
 }
+
+func GetGopath() string {
+	gopath, ok := os.LookupEnv(GopathEnv)
+	if !ok || len(gopath) == 0 {
+		log.Fatal("get current pkg failed: GOPATH env not set")
+	}
+	return gopath
+}
+
+func SetGopath(currentGopath string) {
+	var newGopath string
+	cwdInGopath := false
+	wd := MustGetwd()
+	for _, newGopath = range strings.Split(currentGopath, ":") {
+		if strings.HasPrefix(filepath.Dir(wd), newGopath) {
+			cwdInGopath = true
+			break
+		}
+	}
+	if !cwdInGopath {
+		log.Fatalf("check current pkg failed: must run from gopath")
+	}
+	os.Setenv(GopathEnv, newGopath)
+}