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bae9f6d2 JC |
1 | package config |
2 | ||
3 | import ( | |
4 | "fmt" | |
5 | "strconv" | |
6 | "strings" | |
7 | ||
8 | "github.com/hashicorp/hil/ast" | |
9 | ) | |
10 | ||
11 | // An InterpolatedVariable is a variable reference within an interpolation. | |
12 | // | |
13 | // Implementations of this interface represents various sources where | |
14 | // variables can come from: user variables, resources, etc. | |
15 | type InterpolatedVariable interface { | |
16 | FullKey() string | |
17 | } | |
18 | ||
19 | // CountVariable is a variable for referencing information about | |
20 | // the count. | |
21 | type CountVariable struct { | |
22 | Type CountValueType | |
23 | key string | |
24 | } | |
25 | ||
26 | // CountValueType is the type of the count variable that is referenced. | |
27 | type CountValueType byte | |
28 | ||
29 | const ( | |
30 | CountValueInvalid CountValueType = iota | |
31 | CountValueIndex | |
32 | ) | |
33 | ||
34 | // A ModuleVariable is a variable that is referencing the output | |
35 | // of a module, such as "${module.foo.bar}" | |
36 | type ModuleVariable struct { | |
37 | Name string | |
38 | Field string | |
39 | key string | |
40 | } | |
41 | ||
42 | // A PathVariable is a variable that references path information about the | |
43 | // module. | |
44 | type PathVariable struct { | |
45 | Type PathValueType | |
46 | key string | |
47 | } | |
48 | ||
49 | type PathValueType byte | |
50 | ||
51 | const ( | |
52 | PathValueInvalid PathValueType = iota | |
53 | PathValueCwd | |
54 | PathValueModule | |
55 | PathValueRoot | |
56 | ) | |
57 | ||
58 | // A ResourceVariable is a variable that is referencing the field | |
59 | // of a resource, such as "${aws_instance.foo.ami}" | |
60 | type ResourceVariable struct { | |
61 | Mode ResourceMode | |
62 | Type string // Resource type, i.e. "aws_instance" | |
63 | Name string // Resource name | |
64 | Field string // Resource field | |
65 | ||
66 | Multi bool // True if multi-variable: aws_instance.foo.*.id | |
67 | Index int // Index for multi-variable: aws_instance.foo.1.id == 1 | |
68 | ||
69 | key string | |
70 | } | |
71 | ||
72 | // SelfVariable is a variable that is referencing the same resource | |
73 | // it is running on: "${self.address}" | |
74 | type SelfVariable struct { | |
75 | Field string | |
76 | ||
77 | key string | |
78 | } | |
79 | ||
80 | // SimpleVariable is an unprefixed variable, which can show up when users have | |
81 | // strings they are passing down to resources that use interpolation | |
82 | // internally. The template_file resource is an example of this. | |
83 | type SimpleVariable struct { | |
84 | Key string | |
85 | } | |
86 | ||
87 | // TerraformVariable is a "terraform."-prefixed variable used to access | |
88 | // metadata about the Terraform run. | |
89 | type TerraformVariable struct { | |
90 | Field string | |
91 | key string | |
92 | } | |
93 | ||
94 | // A UserVariable is a variable that is referencing a user variable | |
95 | // that is inputted from outside the configuration. This looks like | |
96 | // "${var.foo}" | |
97 | type UserVariable struct { | |
98 | Name string | |
99 | Elem string | |
100 | ||
101 | key string | |
102 | } | |
103 | ||
104 | func NewInterpolatedVariable(v string) (InterpolatedVariable, error) { | |
105 | if strings.HasPrefix(v, "count.") { | |
106 | return NewCountVariable(v) | |
107 | } else if strings.HasPrefix(v, "path.") { | |
108 | return NewPathVariable(v) | |
109 | } else if strings.HasPrefix(v, "self.") { | |
110 | return NewSelfVariable(v) | |
111 | } else if strings.HasPrefix(v, "terraform.") { | |
112 | return NewTerraformVariable(v) | |
113 | } else if strings.HasPrefix(v, "var.") { | |
114 | return NewUserVariable(v) | |
115 | } else if strings.HasPrefix(v, "module.") { | |
116 | return NewModuleVariable(v) | |
117 | } else if !strings.ContainsRune(v, '.') { | |
118 | return NewSimpleVariable(v) | |
119 | } else { | |
120 | return NewResourceVariable(v) | |
121 | } | |
122 | } | |
123 | ||
124 | func NewCountVariable(key string) (*CountVariable, error) { | |
125 | var fieldType CountValueType | |
126 | parts := strings.SplitN(key, ".", 2) | |
127 | switch parts[1] { | |
128 | case "index": | |
129 | fieldType = CountValueIndex | |
130 | } | |
131 | ||
132 | return &CountVariable{ | |
133 | Type: fieldType, | |
134 | key: key, | |
135 | }, nil | |
136 | } | |
137 | ||
138 | func (c *CountVariable) FullKey() string { | |
139 | return c.key | |
140 | } | |
141 | ||
142 | func NewModuleVariable(key string) (*ModuleVariable, error) { | |
143 | parts := strings.SplitN(key, ".", 3) | |
144 | if len(parts) < 3 { | |
145 | return nil, fmt.Errorf( | |
146 | "%s: module variables must be three parts: module.name.attr", | |
147 | key) | |
148 | } | |
149 | ||
150 | return &ModuleVariable{ | |
151 | Name: parts[1], | |
152 | Field: parts[2], | |
153 | key: key, | |
154 | }, nil | |
155 | } | |
156 | ||
157 | func (v *ModuleVariable) FullKey() string { | |
158 | return v.key | |
159 | } | |
160 | ||
161 | func (v *ModuleVariable) GoString() string { | |
162 | return fmt.Sprintf("*%#v", *v) | |
163 | } | |
164 | ||
165 | func NewPathVariable(key string) (*PathVariable, error) { | |
166 | var fieldType PathValueType | |
167 | parts := strings.SplitN(key, ".", 2) | |
168 | switch parts[1] { | |
169 | case "cwd": | |
170 | fieldType = PathValueCwd | |
171 | case "module": | |
172 | fieldType = PathValueModule | |
173 | case "root": | |
174 | fieldType = PathValueRoot | |
175 | } | |
176 | ||
177 | return &PathVariable{ | |
178 | Type: fieldType, | |
179 | key: key, | |
180 | }, nil | |
181 | } | |
182 | ||
183 | func (v *PathVariable) FullKey() string { | |
184 | return v.key | |
185 | } | |
186 | ||
187 | func NewResourceVariable(key string) (*ResourceVariable, error) { | |
188 | var mode ResourceMode | |
189 | var parts []string | |
190 | if strings.HasPrefix(key, "data.") { | |
191 | mode = DataResourceMode | |
192 | parts = strings.SplitN(key, ".", 4) | |
193 | if len(parts) < 4 { | |
194 | return nil, fmt.Errorf( | |
195 | "%s: data variables must be four parts: data.TYPE.NAME.ATTR", | |
196 | key) | |
197 | } | |
198 | ||
199 | // Don't actually need the "data." prefix for parsing, since it's | |
200 | // always constant. | |
201 | parts = parts[1:] | |
202 | } else { | |
203 | mode = ManagedResourceMode | |
204 | parts = strings.SplitN(key, ".", 3) | |
205 | if len(parts) < 3 { | |
206 | return nil, fmt.Errorf( | |
207 | "%s: resource variables must be three parts: TYPE.NAME.ATTR", | |
208 | key) | |
209 | } | |
210 | } | |
211 | ||
212 | field := parts[2] | |
213 | multi := false | |
214 | var index int | |
215 | ||
216 | if idx := strings.Index(field, "."); idx != -1 { | |
217 | indexStr := field[:idx] | |
218 | multi = indexStr == "*" | |
219 | index = -1 | |
220 | ||
221 | if !multi { | |
222 | indexInt, err := strconv.ParseInt(indexStr, 0, 0) | |
223 | if err == nil { | |
224 | multi = true | |
225 | index = int(indexInt) | |
226 | } | |
227 | } | |
228 | ||
229 | if multi { | |
230 | field = field[idx+1:] | |
231 | } | |
232 | } | |
233 | ||
234 | return &ResourceVariable{ | |
235 | Mode: mode, | |
236 | Type: parts[0], | |
237 | Name: parts[1], | |
238 | Field: field, | |
239 | Multi: multi, | |
240 | Index: index, | |
241 | key: key, | |
242 | }, nil | |
243 | } | |
244 | ||
245 | func (v *ResourceVariable) ResourceId() string { | |
246 | switch v.Mode { | |
247 | case ManagedResourceMode: | |
248 | return fmt.Sprintf("%s.%s", v.Type, v.Name) | |
249 | case DataResourceMode: | |
250 | return fmt.Sprintf("data.%s.%s", v.Type, v.Name) | |
251 | default: | |
252 | panic(fmt.Errorf("unknown resource mode %s", v.Mode)) | |
253 | } | |
254 | } | |
255 | ||
256 | func (v *ResourceVariable) FullKey() string { | |
257 | return v.key | |
258 | } | |
259 | ||
260 | func NewSelfVariable(key string) (*SelfVariable, error) { | |
261 | field := key[len("self."):] | |
262 | ||
263 | return &SelfVariable{ | |
264 | Field: field, | |
265 | ||
266 | key: key, | |
267 | }, nil | |
268 | } | |
269 | ||
270 | func (v *SelfVariable) FullKey() string { | |
271 | return v.key | |
272 | } | |
273 | ||
274 | func (v *SelfVariable) GoString() string { | |
275 | return fmt.Sprintf("*%#v", *v) | |
276 | } | |
277 | ||
278 | func NewSimpleVariable(key string) (*SimpleVariable, error) { | |
279 | return &SimpleVariable{key}, nil | |
280 | } | |
281 | ||
282 | func (v *SimpleVariable) FullKey() string { | |
283 | return v.Key | |
284 | } | |
285 | ||
286 | func (v *SimpleVariable) GoString() string { | |
287 | return fmt.Sprintf("*%#v", *v) | |
288 | } | |
289 | ||
290 | func NewTerraformVariable(key string) (*TerraformVariable, error) { | |
291 | field := key[len("terraform."):] | |
292 | return &TerraformVariable{ | |
293 | Field: field, | |
294 | key: key, | |
295 | }, nil | |
296 | } | |
297 | ||
298 | func (v *TerraformVariable) FullKey() string { | |
299 | return v.key | |
300 | } | |
301 | ||
302 | func (v *TerraformVariable) GoString() string { | |
303 | return fmt.Sprintf("*%#v", *v) | |
304 | } | |
305 | ||
306 | func NewUserVariable(key string) (*UserVariable, error) { | |
307 | name := key[len("var."):] | |
308 | elem := "" | |
309 | if idx := strings.Index(name, "."); idx > -1 { | |
310 | elem = name[idx+1:] | |
311 | name = name[:idx] | |
312 | } | |
313 | ||
314 | if len(elem) > 0 { | |
315 | return nil, fmt.Errorf("Invalid dot index found: 'var.%s.%s'. Values in maps and lists can be referenced using square bracket indexing, like: 'var.mymap[\"key\"]' or 'var.mylist[1]'.", name, elem) | |
316 | } | |
317 | ||
318 | return &UserVariable{ | |
319 | key: key, | |
320 | ||
321 | Name: name, | |
322 | Elem: elem, | |
323 | }, nil | |
324 | } | |
325 | ||
326 | func (v *UserVariable) FullKey() string { | |
327 | return v.key | |
328 | } | |
329 | ||
330 | func (v *UserVariable) GoString() string { | |
331 | return fmt.Sprintf("*%#v", *v) | |
332 | } | |
333 | ||
334 | // DetectVariables takes an AST root and returns all the interpolated | |
335 | // variables that are detected in the AST tree. | |
336 | func DetectVariables(root ast.Node) ([]InterpolatedVariable, error) { | |
337 | var result []InterpolatedVariable | |
338 | var resultErr error | |
339 | ||
340 | // Visitor callback | |
341 | fn := func(n ast.Node) ast.Node { | |
342 | if resultErr != nil { | |
343 | return n | |
344 | } | |
345 | ||
346 | switch vn := n.(type) { | |
347 | case *ast.VariableAccess: | |
348 | v, err := NewInterpolatedVariable(vn.Name) | |
349 | if err != nil { | |
350 | resultErr = err | |
351 | return n | |
352 | } | |
353 | result = append(result, v) | |
354 | case *ast.Index: | |
355 | if va, ok := vn.Target.(*ast.VariableAccess); ok { | |
356 | v, err := NewInterpolatedVariable(va.Name) | |
357 | if err != nil { | |
358 | resultErr = err | |
359 | return n | |
360 | } | |
361 | result = append(result, v) | |
362 | } | |
363 | if va, ok := vn.Key.(*ast.VariableAccess); ok { | |
364 | v, err := NewInterpolatedVariable(va.Name) | |
365 | if err != nil { | |
366 | resultErr = err | |
367 | return n | |
368 | } | |
369 | result = append(result, v) | |
370 | } | |
371 | default: | |
372 | return n | |
373 | } | |
374 | ||
375 | return n | |
376 | } | |
377 | ||
378 | // Visitor pattern | |
379 | root.Accept(fn) | |
380 | ||
381 | if resultErr != nil { | |
382 | return nil, resultErr | |
383 | } | |
384 | ||
385 | return result, nil | |
386 | } |