pkg/runtime: simplify Utsname string conversion (#5625)

Use Utsname from golang.org/x/sys/unix which contains byte array
instead of int8/uint8 array members. This allows to simplify the string
conversions of these members.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

pkg/runtime/uname_linux.go

@@ -14,22 +14,24 @@
 package runtime
 
 import (
-	"syscall"
+	"bytes"
+
+	"golang.org/x/sys/unix"
 )
 
 // Uname returns the uname of the host machine.
 func Uname() string {
-	buf := syscall.Utsname{}
-	err := syscall.Uname(&buf)
+	buf := unix.Utsname{}
+	err := unix.Uname(&buf)
 	if err != nil {
-		panic("syscall.Uname failed: " + err.Error())
+		panic("unix.Uname failed: " + err.Error())
 	}
 
-	str := "(" + charsToString(buf.Sysname[:])
-	str += " " + charsToString(buf.Release[:])
-	str += " " + charsToString(buf.Version[:])
-	str += " " + charsToString(buf.Machine[:])
-	str += " " + charsToString(buf.Nodename[:])
-	str += " " + charsToString(buf.Domainname[:]) + ")"
+	str := "(" + string(buf.Sysname[:bytes.IndexByte(buf.Sysname[:], 0)])
+	str += " " + string(buf.Release[:bytes.IndexByte(buf.Release[:], 0)])
+	str += " " + string(buf.Version[:bytes.IndexByte(buf.Version[:], 0)])
+	str += " " + string(buf.Machine[:bytes.IndexByte(buf.Machine[:], 0)])
+	str += " " + string(buf.Nodename[:bytes.IndexByte(buf.Nodename[:], 0)])
+	str += " " + string(buf.Domainname[:bytes.IndexByte(buf.Domainname[:], 0)]) + ")"
 	return str
 }

pkg/runtime/uname_linux_int8.go

@@ -1,28 +0,0 @@
-// Copyright 2017 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// +build 386 amd64 arm64 mips64 mips64le mips mipsle
-// +build linux
-
-package runtime
-
-func charsToString(ca []int8) string {
-	s := make([]byte, 0, len(ca))
-	for _, c := range ca {
-		if byte(c) == 0 {
-			break
-		}
-		s = append(s, byte(c))
-	}
-	return string(s)
-}

pkg/runtime/uname_linux_uint8.go

@@ -1,28 +0,0 @@
-// Copyright 2017 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// +build arm ppc64 ppc64le s390x
-// +build linux
-
-package runtime
-
-func charsToString(ca []uint8) string {
-	s := make([]byte, 0, len(ca))
-	for _, c := range ca {
-		if byte(c) == 0 {
-			break
-		}
-		s = append(s, byte(c))
-	}
-	return string(s)
-}