-
Notifications
You must be signed in to change notification settings - Fork 28
/
render.go
238 lines (187 loc) · 6.46 KB
/
render.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
// SPDX-License-Identifier: Apache-2.0
package starlark
import (
"bytes"
"errors"
"fmt"
yaml "github.com/buildkite/yaml"
"go.starlark.net/starlark"
"go.starlark.net/starlarkstruct"
"github.com/go-vela/server/compiler/types/raw"
types "github.com/go-vela/server/compiler/types/yaml"
)
var (
// ErrMissingMainFunc defines the error type when the
// main function does not exist in the provided template.
ErrMissingMainFunc = errors.New("unable to find main function in template")
// ErrInvalidMainFunc defines the error type when the
// main function is invalid within the provided template.
ErrInvalidMainFunc = errors.New("invalid main function (main must be a function) in template")
// ErrInvalidPipelineReturn defines the error type when the
// return type is not a pipeline within the provided template.
ErrInvalidPipelineReturn = errors.New("invalid pipeline return in template")
)
// Render combines the template with the step in the yaml pipeline.
func Render(tmpl string, name string, tName string, environment raw.StringSliceMap, variables map[string]interface{}, limit uint64) (*types.Build, error) {
config := new(types.Build)
thread := &starlark.Thread{Name: name}
// arbitrarily limiting the steps of the thread to 5000 to help prevent infinite loops
// may need to further investigate spawning a separate POSIX process if user input is problematic
// see https://github.com/google/starlark-go/issues/160#issuecomment-466794230 for further details
thread.SetMaxExecutionSteps(limit)
predeclared := starlark.StringDict{"struct": starlark.NewBuiltin("struct", starlarkstruct.Make)}
globals, err := starlark.ExecFile(thread, tName, tmpl, predeclared)
if err != nil {
return nil, err
}
// check the provided template has a main function
mainVal, ok := globals["main"]
if !ok {
return nil, fmt.Errorf("%w: %s", ErrMissingMainFunc, tName)
}
// check the provided main is a function
main, ok := mainVal.(starlark.Callable)
if !ok {
return nil, fmt.Errorf("%w: %s", ErrInvalidMainFunc, tName)
}
// load the user provided vars into a starlark type
userVars, err := convertTemplateVars(variables)
if err != nil {
return nil, err
}
// load the platform provided vars into a starlark type
velaVars, err := convertPlatformVars(environment, name)
if err != nil {
return nil, err
}
// add the user and platform vars to a context to be used
// within the template caller i.e. ctx["vela"] or ctx["vars"]
context := starlark.NewDict(0)
err = context.SetKey(starlark.String("vela"), velaVars)
if err != nil {
return nil, err
}
err = context.SetKey(starlark.String("vars"), userVars)
if err != nil {
return nil, err
}
args := starlark.Tuple([]starlark.Value{context})
// execute Starlark program from Go.
mainVal, err = starlark.Call(thread, main, args, nil)
if err != nil {
return nil, err
}
buf := new(bytes.Buffer)
// extract the pipeline from the starlark program
switch v := mainVal.(type) {
case *starlark.List:
for i := 0; i < v.Len(); i++ {
item := v.Index(i)
buf.WriteString("---\n")
err = writeJSON(buf, item)
if err != nil {
return nil, err
}
buf.WriteString("\n")
}
case *starlark.Dict:
buf.WriteString("---\n")
err = writeJSON(buf, v)
if err != nil {
return nil, err
}
default:
return nil, fmt.Errorf("%w: %s", ErrInvalidPipelineReturn, mainVal.Type())
}
// unmarshal the template to the pipeline
err = yaml.Unmarshal(buf.Bytes(), config)
if err != nil {
return nil, fmt.Errorf("unable to unmarshal yaml: %w", err)
}
// ensure all templated steps have template prefix
for index, newStep := range config.Steps {
config.Steps[index].Name = fmt.Sprintf("%s_%s", name, newStep.Name)
}
return &types.Build{Steps: config.Steps, Secrets: config.Secrets, Services: config.Services, Environment: config.Environment}, nil
}
// RenderBuild renders the templated build.
//
//nolint:lll // ignore function length due to input args
func RenderBuild(tmpl string, b string, envs map[string]string, variables map[string]interface{}, limit uint64) (*types.Build, error) {
config := new(types.Build)
thread := &starlark.Thread{Name: "templated-base"}
// arbitrarily limiting the steps of the thread to 5000 to help prevent infinite loops
// may need to further investigate spawning a separate POSIX process if user input is problematic
// see https://github.com/google/starlark-go/issues/160#issuecomment-466794230 for further details
thread.SetMaxExecutionSteps(limit)
predeclared := starlark.StringDict{"struct": starlark.NewBuiltin("struct", starlarkstruct.Make)}
globals, err := starlark.ExecFile(thread, "templated-base", b, predeclared)
if err != nil {
return nil, err
}
// check the provided template has a main function
mainVal, ok := globals["main"]
if !ok {
return nil, fmt.Errorf("%w: %s", ErrMissingMainFunc, "templated-base")
}
// check the provided main is a function
main, ok := mainVal.(starlark.Callable)
if !ok {
return nil, fmt.Errorf("%w: %s", ErrInvalidMainFunc, "templated-base")
}
// load the user provided vars into a starlark type
userVars, err := convertTemplateVars(variables)
if err != nil {
return nil, err
}
// load the platform provided vars into a starlark type
velaVars, err := convertPlatformVars(envs, tmpl)
if err != nil {
return nil, err
}
// add the user and platform vars to a context to be used
// within the template caller i.e. ctx["vela"] or ctx["vars"]
context := starlark.NewDict(0)
err = context.SetKey(starlark.String("vela"), velaVars)
if err != nil {
return nil, err
}
err = context.SetKey(starlark.String("vars"), userVars)
if err != nil {
return nil, err
}
args := starlark.Tuple([]starlark.Value{context})
// execute Starlark program from Go.
mainVal, err = starlark.Call(thread, main, args, nil)
if err != nil {
return nil, err
}
buf := new(bytes.Buffer)
// extract the pipeline from the starlark program
switch v := mainVal.(type) {
case *starlark.List:
for i := 0; i < v.Len(); i++ {
item := v.Index(i)
buf.WriteString("---\n")
err = writeJSON(buf, item)
if err != nil {
return nil, err
}
buf.WriteString("\n")
}
case *starlark.Dict:
buf.WriteString("---\n")
err = writeJSON(buf, v)
if err != nil {
return nil, err
}
default:
return nil, fmt.Errorf("%w: %s", ErrInvalidPipelineReturn, mainVal.Type())
}
// unmarshal the template to the pipeline
err = yaml.Unmarshal(buf.Bytes(), config)
if err != nil {
return nil, fmt.Errorf("unable to unmarshal yaml: %w", err)
}
return config, nil
}