fix: lookup user error message

pkg/util/command_util.go

@@ -453,7 +453,8 @@ func LookupUser(userStr string) (*user.User, error) {
 		if err != nil {
 			uid, err := getUID(userStr)
 			if err != nil {
-				return nil, err
+				// at this point, the user does not exist and the userStr is not a valid number.
+				return nil, fmt.Errorf("user %v is not a uid and does not exist on the system", userStr)
 			}
 			userObj = &user.User{
 				Uid:     fmt.Sprint(uid),

pkg/util/command_util_test.go

@@ -21,6 +21,7 @@ import (
 	"os/user"
 	"reflect"
 	"sort"
+	"strconv"
 	"testing"
 
 	"github.com/GoogleContainerTools/kaniko/testutil"
@@ -678,9 +679,11 @@ func Test_GetUIDAndGIDFromString(t *testing.T) {
 		groupID uint32
 	}
 
+	currentUserUid, _ := strconv.ParseUint(currentUser.Uid, 10, 32)
+	currentUserGid, _ := strconv.ParseUint(currentUser.Gid, 10, 32)
 	expectedCurrentUser := expected{
-		userID:  currentUser.UID,
-		groupID: currentUser.GID,
+		userID:  uint32(currentUserUid),
+		groupID: uint32(currentUserGid),
 	}
 
 	testCases := []struct {
@@ -692,14 +695,14 @@ func Test_GetUIDAndGIDFromString(t *testing.T) {
 		{
 			testname: "current user uid and gid",
 			args: args{
-				userGroupStr: fmt.Sprintf("%d:%d", currentUser.UID, currentUser.GID),
+				userGroupStr: fmt.Sprintf("%d:%d", currentUserUid, currentUserGid),
 			},
 			expected: expectedCurrentUser,
 		},
 		{
 			testname: "current user username and gid",
 			args: args{
-				userGroupStr: fmt.Sprintf("%s:%d", currentUser.Username, currentUser.GID),
+				userGroupStr: fmt.Sprintf("%s:%d", currentUser.Username, currentUserGid),
 			},
 			expected: expectedCurrentUser,
 		},
@@ -713,7 +716,7 @@ func Test_GetUIDAndGIDFromString(t *testing.T) {
 		{
 			testname: "current user uid and primary group",
 			args: args{
-				userGroupStr: fmt.Sprintf("%d:%s", currentUser.UID, currentUser.PrimaryGroup),
+				userGroupStr: fmt.Sprintf("%d:%s", currentUserUid, currentUser.PrimaryGroup),
 			},
 			expected: expectedCurrentUser,
 		},
@@ -734,7 +737,7 @@ func Test_GetUIDAndGIDFromString(t *testing.T) {
 			},
 			expected: expected{
 				userID:  1001,
-				groupID: uint32(currentUser.GID),
+				groupID: uint32(currentUserGid),
 			},
 		},
 		{
@@ -768,15 +771,15 @@ func Test_GetUIDAndGIDFromString(t *testing.T) {
 		{
 			testname: "only uid and fallback is false",
 			args: args{
-				userGroupStr:  fmt.Sprintf("%d", currentUser.UID),
+				userGroupStr:  fmt.Sprintf("%d", currentUserUid),
 				fallbackToUID: false,
 			},
 			wantErr: true,
 		},
 		{
 			testname: "only uid and fallback is true",
 			args: args{
-				userGroupStr:  fmt.Sprintf("%d", currentUser.UID),
+				userGroupStr:  fmt.Sprintf("%d", currentUserUid),
 				fallbackToUID: true,
 			},
 			expected: expected{
@@ -804,3 +807,51 @@ func Test_GetUIDAndGIDFromString(t *testing.T) {
 		}
 	}
 }
+
+func TestLookupUser(t *testing.T) {
+	currentUser := testutil.GetCurrentUser(t)
+
+	type args struct {
+		userStr string
+	}
+	tests := []struct {
+		testname string
+		args     args
+		expected *user.User
+		wantErr  bool
+	}{
+		{
+			testname: "non-existing user",
+			args: args{
+				userStr: "foobazbar",
+			},
+			wantErr: true,
+		},
+		{
+			testname: "uid",
+			args: args{
+				userStr: "30000",
+			},
+			expected: &user.User{
+				Uid:     "30000",
+				HomeDir: "/",
+			},
+			wantErr: false,
+		},
+		{
+			testname: "current user",
+			args: args{
+				userStr: currentUser.Username,
+			},
+			expected: currentUser.User,
+			wantErr:  false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.testname, func(t *testing.T) {
+			got, err := LookupUser(tt.args.userStr)
+			testutil.CheckErrorAndDeepEqual(t, tt.wantErr, err, tt.expected, got)
+		})
+	}
+
+}

pkg/util/syscall_credentials_test.go

@@ -18,6 +18,7 @@ package util
 
 import (
 	"fmt"
+	"strconv"
 	"syscall"
 	"testing"
 
@@ -26,6 +27,11 @@ import (
 
 func TestSyscallCredentials(t *testing.T) {
 	currentUser := testutil.GetCurrentUser(t)
+	uid, _ := strconv.ParseUint(currentUser.Uid, 10, 32)
+	currentUserUid32 := uint32(uid)
+	gid, _ := strconv.ParseUint(currentUser.Gid, 10, 32)
+	currentUserGid32 := uint32(gid)
+
 	type args struct {
 		userStr string
 	}
@@ -57,11 +63,11 @@ func TestSyscallCredentials(t *testing.T) {
 		{
 			name: "non-existing uid with existing gid",
 			args: args{
-				userStr: fmt.Sprintf("1001:%d", currentUser.GID),
+				userStr: fmt.Sprintf("1001:%d", currentUserGid32),
 			},
 			want: &syscall.Credential{
 				Uid:    1001,
-				Gid:    currentUser.GID,
+				Gid:    currentUserGid32,
 				Groups: []uint32{},
 			},
 		},
@@ -71,9 +77,9 @@ func TestSyscallCredentials(t *testing.T) {
 				userStr: fmt.Sprintf("%s:50000", currentUser.Username),
 			},
 			want: &syscall.Credential{
-				Uid:    currentUser.UID,
+				Uid:    currentUserUid32,
 				Gid:    50000,
-				Groups: []uint32{currentUser.GID},
+				Groups: []uint32{currentUserGid32},
 			},
 		},
 	}

testutil/util.go

@@ -23,7 +23,6 @@ import (
 	"os/user"
 	"path/filepath"
 	"reflect"
-	"strconv"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -44,9 +43,8 @@ func SetupFiles(path string, files map[string]string) error {
 }
 
 type CurrentUser struct {
-	Username     string
-	UID          uint32
-	GID          uint32
+	*user.User
+
 	PrimaryGroup string
 }
 
@@ -64,14 +62,10 @@ func GetCurrentUser(t *testing.T) CurrentUser {
 		t.Fatalf("Could not lookup name of group %s: %s", groups[0], err)
 	}
 	primaryGroup := primaryGroupObj.Name
-	uid, _ := strconv.ParseUint(currentUser.Uid, 10, 32)
-	gid, _ := strconv.ParseUint(currentUser.Gid, 10, 32)
 
 	return CurrentUser{
-		UID:          uint32(uid),
-		GID:          uint32(gid),
+		User:         currentUser,
 		PrimaryGroup: primaryGroup,
-		Username:     currentUser.Username,
 	}
 }