-
Notifications
You must be signed in to change notification settings - Fork 43
/
capture.go
209 lines (176 loc) · 6.04 KB
/
capture.go
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
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
// Copyright (c) 2020 VMware, Inc. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package starlark
import (
"fmt"
"io"
"os"
"path/filepath"
"strings"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"github.com/vmware-tanzu/crash-diagnostics/ssh"
"go.starlark.net/starlark"
"go.starlark.net/starlarkstruct"
)
// captureFunc is a built-in starlark function that runs a provided command and
// captures the result of the command in a specified file stored in workdir.
// If resources and workdir are not provided, captureFunc uses defaults from starlark thread generated
// by previous calls to resources() and crashd_config().
// Starlark format: capture(command-string, cmd="command" [,resources=resources][,workdir=path][,file_name=name][,desc=description])
func captureFunc(thread *starlark.Thread, b *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
var cmdStr, workdir, fileName, desc string
var resources *starlark.List
if err := starlark.UnpackArgs(
identifiers.capture, args, kwargs,
"cmd", &cmdStr,
"resources?", &resources,
"workdir?", &workdir,
"file_name?", &fileName,
"desc?", &desc,
); err != nil {
return starlark.None, fmt.Errorf("%s: %s", identifiers.capture, err)
}
if len(cmdStr) == 0 {
return starlark.None, fmt.Errorf("%s: missing command string", identifiers.capture)
}
if len(workdir) == 0 {
if dir, err := getWorkdirFromThread(thread); err == nil {
workdir = dir
}
}
if len(workdir) == 0 {
workdir = defaults.workdir
}
if resources == nil {
res, err := getResourcesFromThread(thread)
if err != nil {
return starlark.None, fmt.Errorf("%s: %s", identifiers.copyFrom, err)
}
resources = res
}
var agent ssh.Agent
var ok bool
if agentVal := thread.Local(identifiers.sshAgent); agentVal != nil {
agent, ok = agentVal.(ssh.Agent)
if !ok {
return starlark.None, errors.New("unable to fetch ssh-agent")
}
}
results, err := execCapture(cmdStr, workdir, fileName, desc, agent, resources)
if err != nil {
return starlark.None, fmt.Errorf("%s: %s", identifiers.capture, err)
}
// build list of struct as result
var resultList []starlark.Value
for _, result := range results {
if len(results) == 1 {
return result.toStarlarkStruct(), nil
}
resultList = append(resultList, result.toStarlarkStruct())
}
return starlark.NewList(resultList), nil
}
func execCapture(cmdStr, rootPath, fileName, desc string, agent ssh.Agent, resources *starlark.List) ([]commandResult, error) {
if resources == nil {
return nil, fmt.Errorf("%s: missing resources", identifiers.capture)
}
logrus.Debugf("%s: executing command on %d resources", identifiers.capture, resources.Len())
var results []commandResult
for i := 0; i < resources.Len(); i++ {
val := resources.Index(i)
res, ok := val.(*starlarkstruct.Struct)
if !ok {
return nil, fmt.Errorf("%s: unexpected resource type", identifiers.capture)
}
val, err := res.Attr("kind")
if err != nil {
return nil, fmt.Errorf("%s: resource.kind: %s", identifiers.capture, err)
}
kind := val.(starlark.String)
val, err = res.Attr("transport")
if err != nil {
return nil, fmt.Errorf("%s: resource.transport: %s", identifiers.capture, err)
}
transport := val.(starlark.String)
val, err = res.Attr("host")
if err != nil {
return nil, fmt.Errorf("%s: resource.host: %s", identifiers.capture, err)
}
host := string(val.(starlark.String))
rootDir := filepath.Join(rootPath, sanitizeStr(host))
switch {
case string(kind) == identifiers.hostResource && string(transport) == "ssh":
result, err := execCaptureSSH(host, cmdStr, rootDir, fileName, desc, agent, res)
if err != nil {
logrus.Errorf("%s failed: cmd=[%s]: %s", identifiers.capture, cmdStr, err)
}
results = append(results, result)
default:
logrus.Errorf("%s: unsupported or invalid resource kind: %s", identifiers.capture, kind)
continue
}
}
return results, nil
}
func execCaptureSSH(host, cmdStr, rootDir, fileName, desc string, agent ssh.Agent, res *starlarkstruct.Struct) (commandResult, error) {
sshCfg := starlarkstruct.FromKeywords(starlarkstruct.Default, makeDefaultSSHConfig())
if val, err := res.Attr(identifiers.sshCfg); err == nil {
if cfg, ok := val.(*starlarkstruct.Struct); ok {
sshCfg = cfg
}
}
args, err := getSSHArgsFromCfg(sshCfg)
if err != nil {
return commandResult{}, err
}
args.Host = host
// create dir for the host
if err := os.MkdirAll(rootDir, 0744); err != nil && !os.IsExist(err) {
return commandResult{}, err
}
logrus.Debugf("%s: created capture dir: %s", identifiers.capture, rootDir)
if len(fileName) == 0 {
fileName = fmt.Sprintf("%s.txt", sanitizeStr(cmdStr))
}
filePath := filepath.Join(rootDir, fileName)
logrus.Debugf("%s: capturing output of [cmd=%s] => [%s] from %s using ssh", identifiers.capture, cmdStr, filePath, args.Host)
reader, err := ssh.RunRead(args, agent, cmdStr)
if err != nil {
logrus.Errorf("%s failed: %s", identifiers.capture, err)
if err := captureOutput(strings.NewReader(err.Error()), filePath, fmt.Sprintf("%s: failed", cmdStr), false); err != nil {
logrus.Errorf("%s output failed: %s", identifiers.capture, err)
return commandResult{resource: args.Host, result: filePath, err: err}, err
}
}
if err := captureOutput(reader, filePath, desc, false); err != nil {
logrus.Errorf("%s output failed: %s", identifiers.capture, err)
return commandResult{resource: args.Host, result: filePath, err: err}, err
}
return commandResult{resource: args.Host, result: filePath, err: err}, nil
}
func captureOutput(source io.Reader, filePath, desc string, append bool) error {
if source == nil {
return fmt.Errorf("source reader is nill")
}
flag := os.O_CREATE | os.O_WRONLY
if append {
flag |= os.O_APPEND
} else {
flag |= os.O_TRUNC
}
file, err := os.OpenFile(filePath, flag, 0644)
if err != nil {
return err
}
defer file.Close()
if len(desc) > 0 {
if _, err := file.WriteString(fmt.Sprintf("%s\n", desc)); err != nil {
return err
}
}
if _, err := io.Copy(file, source); err != nil {
return err
}
return nil
}