forked from purpleidea/mgmt
-
Notifications
You must be signed in to change notification settings - Fork 0
/
gapi.go
295 lines (262 loc) · 8.08 KB
/
gapi.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
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
// Mgmt
// Copyright (C) 2013-2018+ James Shubin and the project contributors
// Written by James Shubin <james@shubin.ca> and the project contributors
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package lang
import (
"fmt"
"strings"
"sync"
"github.com/purpleidea/mgmt/engine"
"github.com/purpleidea/mgmt/gapi"
"github.com/purpleidea/mgmt/pgraph"
multierr "github.com/hashicorp/go-multierror"
errwrap "github.com/pkg/errors"
"github.com/urfave/cli"
)
const (
// Name is the name of this frontend.
Name = "lang"
// Start is the entry point filename that we use. It is arbitrary.
Start = "/start." + FileNameExtension // FIXME: replace with a proper code entry point schema (directory schema)
)
func init() {
gapi.Register(Name, func() gapi.GAPI { return &GAPI{} }) // register
}
// GAPI implements the main lang GAPI interface.
type GAPI struct {
InputURI string // input URI of code file system to run
lang *Lang // lang struct
data gapi.Data
initialized bool
closeChan chan struct{}
wg *sync.WaitGroup // sync group for tunnel go routines
}
// Cli takes a cli.Context, and returns our GAPI if activated. All arguments
// should take the prefix of the registered name. On activation, if there are
// any validation problems, you should return an error. If this was not
// activated, then you should return a nil GAPI and a nil error.
func (obj *GAPI) Cli(c *cli.Context, fs engine.Fs) (*gapi.Deploy, error) {
if s := c.String(Name); c.IsSet(Name) {
if s == "" {
return nil, fmt.Errorf("input code is empty")
}
// read through this local path, and store it in our file system
// since our deploy should work anywhere in the cluster, let the
// engine ensure that this file system is replicated everywhere!
// TODO: single file input for now
if err := gapi.CopyFileToFs(fs, s, Start); err != nil {
return nil, errwrap.Wrapf(err, "can't copy code from `%s` to `%s`", s, Start)
}
return &gapi.Deploy{
Name: Name,
Noop: c.GlobalBool("noop"),
Sema: c.GlobalInt("sema"),
GAPI: &GAPI{
InputURI: fs.URI(),
// TODO: add properties here...
},
}, nil
}
return nil, nil // we weren't activated!
}
// CliFlags returns a list of flags used by this deploy subcommand.
func (obj *GAPI) CliFlags() []cli.Flag {
return []cli.Flag{
cli.StringFlag{
Name: fmt.Sprintf("%s, %s", Name, Name[0:1]),
Value: "",
Usage: "language code path to deploy",
},
}
}
// Init initializes the lang GAPI struct.
func (obj *GAPI) Init(data gapi.Data) error {
if obj.initialized {
return fmt.Errorf("already initialized")
}
if obj.InputURI == "" {
return fmt.Errorf("the InputURI param must be specified")
}
obj.data = data // store for later
obj.closeChan = make(chan struct{})
obj.wg = &sync.WaitGroup{}
obj.initialized = true
return nil
}
// LangInit is a wrapper around the lang Init method.
func (obj *GAPI) LangInit() error {
if obj.lang != nil {
return nil // already ran init, close first!
}
fs, err := obj.data.World.Fs(obj.InputURI) // open the remote file system
if err != nil {
return errwrap.Wrapf(err, "can't load code from file system `%s`", obj.InputURI)
}
b, err := fs.ReadFile(Start) // read the single file out of it
if err != nil {
return errwrap.Wrapf(err, "can't read code from file `%s`", Start)
}
code := strings.NewReader(string(b))
obj.lang = &Lang{
Input: code, // string as an interface that satisfies io.Reader
Hostname: obj.data.Hostname,
World: obj.data.World,
Debug: obj.data.Debug,
Logf: func(format string, v ...interface{}) {
// TODO: add the Name prefix in parent logger
obj.data.Logf(Name+": "+format, v...)
},
}
if err := obj.lang.Init(); err != nil {
return errwrap.Wrapf(err, "can't init the lang")
}
return nil
}
// LangClose is a wrapper around the lang Close method.
func (obj *GAPI) LangClose() error {
if obj.lang != nil {
err := obj.lang.Close()
obj.lang = nil // clear it to avoid double closing
return errwrap.Wrapf(err, "can't close the lang") // nil passthrough
}
return nil
}
// Graph returns a current Graph.
func (obj *GAPI) Graph() (*pgraph.Graph, error) {
if !obj.initialized {
return nil, fmt.Errorf("%s: GAPI is not initialized", Name)
}
g, err := obj.lang.Interpret()
if err != nil {
return nil, errwrap.Wrapf(err, "%s: interpret error", Name)
}
return g, nil
}
// Next returns nil errors every time there could be a new graph.
func (obj *GAPI) Next() chan gapi.Next {
ch := make(chan gapi.Next)
obj.wg.Add(1)
go func() {
defer obj.wg.Done()
defer close(ch) // this will run before the obj.wg.Done()
if !obj.initialized {
next := gapi.Next{
Err: fmt.Errorf("%s: GAPI is not initialized", Name),
Exit: true, // exit, b/c programming error?
}
select {
case ch <- next:
case <-obj.closeChan:
}
return
}
startChan := make(chan struct{}) // start signal
close(startChan) // kick it off!
streamChan := make(chan error)
//defer obj.LangClose() // close any old lang
var ok bool
for {
var err error
var langSwap bool // do we need to swap the lang object?
select {
// TODO: this should happen in ConfigWatch instead :)
case <-startChan: // kick the loop once at start
startChan = nil // disable
err = nil // set nil as the message to send
langSwap = true
case err, ok = <-streamChan: // a variable changed
if !ok { // the channel closed!
return
}
case <-obj.closeChan:
return
}
obj.data.Logf("generating new graph...")
// skip this to pass through the err if present
if langSwap && err == nil {
obj.data.Logf("swap!")
// run up to these three but fail on err
if e := obj.LangClose(); e != nil { // close any old lang
err = e // pass through the err
} else if e := obj.LangInit(); e != nil { // init the new one!
err = e // pass through the err
// Always run LangClose after LangInit
// when done. This is currently needed
// because we should tell the lang obj
// to shut down all the running facts.
if e := obj.LangClose(); e != nil {
err = multierr.Append(err, e) // list of errors
}
} else {
if obj.data.NoStreamWatch { // TODO: do we want to allow this for the lang?
obj.data.Logf("warning: language will not stream")
// send only one event
limitChan := make(chan error)
obj.wg.Add(1)
go func() {
defer obj.wg.Done()
defer close(limitChan)
select {
// only one
case err, ok := <-obj.lang.Stream():
if !ok {
return
}
select {
case limitChan <- err:
case <-obj.closeChan:
return
}
case <-obj.closeChan:
return
}
}()
streamChan = limitChan
} else {
// stream for lang events
streamChan = obj.lang.Stream() // update stream
}
continue // wait for stream to trigger
}
}
next := gapi.Next{
Exit: err != nil, // TODO: do we want to shutdown?
Err: err,
}
select {
case ch <- next: // trigger a run (send a msg)
if err != nil {
return
}
// unblock if we exit while waiting to send!
case <-obj.closeChan:
return
}
}
}()
return ch
}
// Close shuts down the lang GAPI.
func (obj *GAPI) Close() error {
if !obj.initialized {
return fmt.Errorf("%s: GAPI is not initialized", Name)
}
close(obj.closeChan)
obj.wg.Wait()
obj.LangClose() // close lang, esp. if blocked in Stream() wait
obj.initialized = false // closed = true
return nil
}