sslobodr | d046be8 | 2019-01-16 10:02:22 -0500 | [diff] [blame^] | 1 | // Copyright 2018 The Prometheus Authors |
| 2 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 3 | // you may not use this file except in compliance with the License. |
| 4 | // You may obtain a copy of the License at |
| 5 | // |
| 6 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 7 | // |
| 8 | // Unless required by applicable law or agreed to in writing, software |
| 9 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 10 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 11 | // See the License for the specific language governing permissions and |
| 12 | // limitations under the License. |
| 13 | |
| 14 | package procfs |
| 15 | |
| 16 | import ( |
| 17 | "fmt" |
| 18 | "os" |
| 19 | "strconv" |
| 20 | "strings" |
| 21 | ) |
| 22 | |
| 23 | // Namespace represents a single namespace of a process. |
| 24 | type Namespace struct { |
| 25 | Type string // Namespace type. |
| 26 | Inode uint32 // Inode number of the namespace. If two processes are in the same namespace their inodes will match. |
| 27 | } |
| 28 | |
| 29 | // Namespaces contains all of the namespaces that the process is contained in. |
| 30 | type Namespaces map[string]Namespace |
| 31 | |
| 32 | // NewNamespaces reads from /proc/[pid/ns/* to get the namespaces of which the |
| 33 | // process is a member. |
| 34 | func (p Proc) NewNamespaces() (Namespaces, error) { |
| 35 | d, err := os.Open(p.path("ns")) |
| 36 | if err != nil { |
| 37 | return nil, err |
| 38 | } |
| 39 | defer d.Close() |
| 40 | |
| 41 | names, err := d.Readdirnames(-1) |
| 42 | if err != nil { |
| 43 | return nil, fmt.Errorf("failed to read contents of ns dir: %v", err) |
| 44 | } |
| 45 | |
| 46 | ns := make(Namespaces, len(names)) |
| 47 | for _, name := range names { |
| 48 | target, err := os.Readlink(p.path("ns", name)) |
| 49 | if err != nil { |
| 50 | return nil, err |
| 51 | } |
| 52 | |
| 53 | fields := strings.SplitN(target, ":", 2) |
| 54 | if len(fields) != 2 { |
| 55 | return nil, fmt.Errorf("failed to parse namespace type and inode from '%v'", target) |
| 56 | } |
| 57 | |
| 58 | typ := fields[0] |
| 59 | inode, err := strconv.ParseUint(strings.Trim(fields[1], "[]"), 10, 32) |
| 60 | if err != nil { |
| 61 | return nil, fmt.Errorf("failed to parse inode from '%v': %v", fields[1], err) |
| 62 | } |
| 63 | |
| 64 | ns[name] = Namespace{typ, uint32(inode)} |
| 65 | } |
| 66 | |
| 67 | return ns, nil |
| 68 | } |