container: support hostprocess containers and expose kubernetes labels (#1911)

internal/headers/guid/guid.go

@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: Apache-2.0
+//
+// Copyright 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.
+
+//go:build windows
+
+package guid
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"golang.org/x/sys/windows"
+)
+
+type GUID windows.GUID
+
+// FromString parses a string containing a GUID and returns the GUID. The only
+// format currently supported is the `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`
+// format.
+func FromString(s string) (GUID, error) {
+	if len(s) != 36 {
+		return GUID{}, fmt.Errorf("invalid GUID %q", s)
+	}
+
+	if s[8] != '-' || s[13] != '-' || s[18] != '-' || s[23] != '-' {
+		return GUID{}, fmt.Errorf("invalid GUID %q", s)
+	}
+
+	var g GUID
+
+	data1, err := strconv.ParseUint(s[0:8], 16, 32)
+	if err != nil {
+		return GUID{}, fmt.Errorf("invalid GUID %q", s)
+	}
+
+	g.Data1 = uint32(data1)
+
+	data2, err := strconv.ParseUint(s[9:13], 16, 16)
+	if err != nil {
+		return GUID{}, fmt.Errorf("invalid GUID %q", s)
+	}
+
+	g.Data2 = uint16(data2)
+
+	data3, err := strconv.ParseUint(s[14:18], 16, 16)
+	if err != nil {
+		return GUID{}, fmt.Errorf("invalid GUID %q", s)
+	}
+
+	g.Data3 = uint16(data3)
+
+	for i, x := range []int{19, 21, 24, 26, 28, 30, 32, 34} {
+		v, err := strconv.ParseUint(s[x:x+2], 16, 8)
+		if err != nil {
+			return GUID{}, fmt.Errorf("invalid GUID %q", s)
+		}
+
+		g.Data4[i] = uint8(v)
+	}
+
+	return g, nil
+}
+
+func (g *GUID) UnmarshalJSON(b []byte) error {
+	guid, err := FromString(strings.Trim(strings.Trim(string(b), `"`), `{}`))
+	if err != nil {
+		return err
+	}
+
+	*g = guid
+
+	return nil
+}
+
+func (g *GUID) String() string {
+	return fmt.Sprintf(
+		"%08x-%04x-%04x-%04x-%012x",
+		g.Data1,
+		g.Data2,
+		g.Data3,
+		g.Data4[:2],
+		g.Data4[2:])
+}