1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
// Package rancher wraps Rancher commands necessary for K8s inspection.
package rancher
import (
"bytes"
"fmt"
"os/exec"
"check"
)
const (
bin = "rancher"
paramHost = "--host"
cmdHosts = "hosts"
cmdHostsParams = "--quiet"
cmdDocker = "docker"
cmdDockerCmdPs = "ps"
cmdDockerCmdPsParams = "--no-trunc"
cmdDockerCmdPsFilter = "--filter"
cmdDockerCmdPsFilterArgs = "label=io.rancher.stack_service.name="
cmdDockerCmdPsFormat = "--format"
cmdDockerCmdPsFormatArgs = "{{.Command}}"
)
// Rancher implements Informer interface.
type Rancher struct {
check.Informer
}
// GetAPIParams returns parameters of running Kubernetes API server.
// It queries default environment set in configuration file.
func (r *Rancher) GetAPIParams() ([]string, error) {
return getProcessParams(check.APIProcess, check.APIService)
}
// GetSchedulerParams returns parameters of running Kubernetes scheduler.
// It queries default environment set in configuration file.
func (r *Rancher) GetSchedulerParams() ([]string, error) {
return getProcessParams(check.SchedulerProcess, check.SchedulerService)
}
// GetControllerManagerParams returns parameters of running Kubernetes scheduler.
// It queries default environment set in configuration file.
func (r *Rancher) GetControllerManagerParams() ([]string, error) {
return getProcessParams(check.ControllerManagerProcess, check.ControllerManagerService)
}
// GetEtcdParams returns parameters of running etcd.
// It queries only cluster nodes with "controlplane" role.
func (r *Rancher) GetEtcdParams() ([]string, error) {
return []string{}, check.ErrNotImplemented
}
func getProcessParams(process check.Command, service check.Service) ([]string, error) {
hosts, err := listHosts()
if err != nil {
return []string{}, err
}
for _, host := range hosts {
cmd, err := getPsCmdOutput(host, service)
if err != nil {
return []string{}, err
}
cmd = trimOutput(cmd) // TODO: improve `docker ps` query format.
if len(cmd) > 0 {
i := bytes.Index(cmd, []byte(process.String()))
if i == -1 {
return []string{}, fmt.Errorf("missing %s command", process)
}
return btos(cmd[i+len(process.String()):]), nil
}
}
return []string{}, nil
}
// listHosts lists IDs of active hosts.
// It queries default environment set in configuration file.
func listHosts() ([]string, error) {
cmd := exec.Command(bin, cmdHosts, cmdHostsParams)
out, err := cmd.Output()
if err != nil {
return nil, err
}
return btos(out), nil
}
// getPsCmdOutput returns running Kubernetes service command with its parameters.
// It queries default environment set in configuration file.
func getPsCmdOutput(host string, service check.Service) ([]byte, error) {
// Following is equivalent to:
// $ rancher --host $HOST \
// docker ps --no-trunc \
// --filter "label=io.rancher.stack_service.name=$SERVICE" \
// --format "{{.Command}}"
cmd := exec.Command(bin, paramHost, host,
cmdDocker, cmdDockerCmdPs, cmdDockerCmdPsParams,
cmdDockerCmdPsFilter, cmdDockerCmdPsFilterArgs+service.String(),
cmdDockerCmdPsFormat, cmdDockerCmdPsFormatArgs)
out, err := cmd.Output()
if err != nil {
return nil, err
}
return out, nil
}
// trimOutput removes trailing new line and brackets from output.
func trimOutput(b []byte) []byte {
b = bytes.TrimSpace(b)
b = bytes.TrimPrefix(b, []byte("["))
b = bytes.TrimSuffix(b, []byte("]"))
return b
}
// btos converts slice of bytes to slice of strings split by white space characters.
func btos(in []byte) []string {
var out []string
for _, b := range bytes.Fields(in) {
out = append(out, string(b))
}
return out
}
|
