cubefs

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// Copyright 2018 The Prometheus Authors
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package procfs
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import (
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	"fmt"
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	"os"
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	"strconv"
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	"strings"
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)
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// Namespace represents a single namespace of a process.
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type Namespace struct {
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	Type  string // Namespace type.
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	Inode uint32 // Inode number of the namespace. If two processes are in the same namespace their inodes will match.
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}
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// Namespaces contains all of the namespaces that the process is contained in.
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type Namespaces map[string]Namespace
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// Namespaces reads from /proc/<pid>/ns/* to get the namespaces of which the
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// process is a member.
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func (p Proc) Namespaces() (Namespaces, error) {
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	d, err := os.Open(p.path("ns"))
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	if err != nil {
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		return nil, err
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	}
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	defer d.Close()
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	names, err := d.Readdirnames(-1)
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	if err != nil {
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		return nil, fmt.Errorf("failed to read contents of ns dir: %w", err)
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	}
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	ns := make(Namespaces, len(names))
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	for _, name := range names {
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		target, err := os.Readlink(p.path("ns", name))
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		if err != nil {
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			return nil, err
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		}
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		fields := strings.SplitN(target, ":", 2)
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		if len(fields) != 2 {
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			return nil, fmt.Errorf("failed to parse namespace type and inode from %q", target)
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		}
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		typ := fields[0]
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		inode, err := strconv.ParseUint(strings.Trim(fields[1], "[]"), 10, 32)
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		if err != nil {
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			return nil, fmt.Errorf("failed to parse inode from %q: %w", fields[1], err)
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		}
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		ns[name] = Namespace{typ, uint32(inode)}
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	}
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	return ns, nil
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}
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