cloudflare/pint
Publicmirrored from https://github.com/cloudflare/pintAvailable
internal/parser/parser.go
415lines · modecode
| 1 | package parser |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "fmt" |
| 6 | "strings" |
| 7 | |
| 8 | "gopkg.in/yaml.v3" |
| 9 | |
| 10 | "github.com/cloudflare/pint/internal/comments" |
| 11 | ) |
| 12 | |
| 13 | const ( |
| 14 | recordKey = "record" |
| 15 | exprKey = "expr" |
| 16 | labelsKey = "labels" |
| 17 | alertKey = "alert" |
| 18 | forKey = "for" |
| 19 | keepFiringForKey = "keep_firing_for" |
| 20 | annotationsKey = "annotations" |
| 21 | ) |
| 22 | |
| 23 | var ErrRuleCommentOnFile = errors.New("this comment is only valid when attached to a rule") |
| 24 | |
| 25 | func NewParser() Parser { |
| 26 | return Parser{} |
| 27 | } |
| 28 | |
| 29 | type Parser struct{} |
| 30 | |
| 31 | func (p Parser) Parse(content []byte) (rules []Rule, err error) { |
| 32 | if len(content) == 0 { |
| 33 | return nil, nil |
| 34 | } |
| 35 | |
| 36 | defer func() { |
| 37 | if r := recover(); r != nil { |
| 38 | err = fmt.Errorf("unable to parse YAML file: %s", r) |
| 39 | } |
| 40 | }() |
| 41 | |
| 42 | var node yaml.Node |
| 43 | err = yaml.Unmarshal(content, &node) |
| 44 | if err != nil { |
| 45 | return nil, err |
| 46 | } |
| 47 | |
| 48 | rules, err = parseNode(content, &node, 0) |
| 49 | return rules, err |
| 50 | } |
| 51 | |
| 52 | func parseNode(content []byte, node *yaml.Node, offset int) (rules []Rule, err error) { |
| 53 | ret, isEmpty, err := parseRule(content, node, offset) |
| 54 | if err != nil { |
| 55 | return nil, err |
| 56 | } |
| 57 | if !isEmpty { |
| 58 | rules = append(rules, ret) |
| 59 | return rules, nil |
| 60 | } |
| 61 | |
| 62 | var rl []Rule |
| 63 | var rule Rule |
| 64 | for _, root := range node.Content { |
| 65 | // nolint: exhaustive |
| 66 | switch root.Kind { |
| 67 | case yaml.SequenceNode: |
| 68 | for _, n := range root.Content { |
| 69 | rl, err = parseNode(content, n, offset) |
| 70 | if err != nil { |
| 71 | return nil, err |
| 72 | } |
| 73 | rules = append(rules, rl...) |
| 74 | } |
| 75 | case yaml.MappingNode: |
| 76 | rule, isEmpty, err = parseRule(content, root, offset) |
| 77 | if err != nil { |
| 78 | return nil, err |
| 79 | } |
| 80 | if !isEmpty { |
| 81 | rules = append(rules, rule) |
| 82 | } else { |
| 83 | for _, n := range root.Content { |
| 84 | rl, err = parseNode(content, n, offset) |
| 85 | if err != nil { |
| 86 | return nil, err |
| 87 | } |
| 88 | rules = append(rules, rl...) |
| 89 | } |
| 90 | } |
| 91 | case yaml.ScalarNode: |
| 92 | if root.Value != string(content) { |
| 93 | c := []byte(root.Value) |
| 94 | var n yaml.Node |
| 95 | err = yaml.Unmarshal(c, &n) |
| 96 | if err == nil { |
| 97 | ret, err := parseNode(c, &n, offset+root.Line) |
| 98 | if err != nil { |
| 99 | return nil, err |
| 100 | } |
| 101 | rules = append(rules, ret...) |
| 102 | } |
| 103 | } |
| 104 | } |
| 105 | } |
| 106 | return rules, nil |
| 107 | } |
| 108 | |
| 109 | func parseRule(content []byte, node *yaml.Node, offset int) (rule Rule, _ bool, err error) { |
| 110 | if node.Kind != yaml.MappingNode { |
| 111 | return rule, true, err |
| 112 | } |
| 113 | |
| 114 | var recordPart *YamlNode |
| 115 | var exprPart *PromQLExpr |
| 116 | var labelsPart *YamlMap |
| 117 | |
| 118 | var alertPart *YamlNode |
| 119 | var forPart *YamlNode |
| 120 | var keepFiringForPart *YamlNode |
| 121 | var annotationsPart *YamlMap |
| 122 | |
| 123 | var key *yaml.Node |
| 124 | unknownKeys := []*yaml.Node{} |
| 125 | |
| 126 | var lines LineRange |
| 127 | |
| 128 | var ruleComments []comments.Comment |
| 129 | |
| 130 | for i, part := range unpackNodes(node) { |
| 131 | if lines.First == 0 || part.Line+offset < lines.First { |
| 132 | lines.First = part.Line + offset |
| 133 | } |
| 134 | lines.Last = max(lines.Last, part.Line+offset) |
| 135 | |
| 136 | if i == 0 && node.HeadComment != "" && part.HeadComment == "" { |
| 137 | part.HeadComment = node.HeadComment |
| 138 | } |
| 139 | if i == 0 && node.LineComment != "" && part.LineComment == "" { |
| 140 | part.LineComment = node.LineComment |
| 141 | } |
| 142 | if i == len(node.Content)-1 && node.FootComment != "" && part.HeadComment == "" { |
| 143 | part.FootComment = node.FootComment |
| 144 | } |
| 145 | for _, s := range mergeComments(part) { |
| 146 | for _, c := range comments.Parse(part.Line, s) { |
| 147 | if comments.IsRuleComment(c.Type) { |
| 148 | ruleComments = append(ruleComments, c) |
| 149 | } |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | if i%2 == 0 { |
| 154 | key = part |
| 155 | } else { |
| 156 | switch key.Value { |
| 157 | case recordKey: |
| 158 | if recordPart != nil { |
| 159 | return duplicatedKeyError(lines, part.Line+offset, recordKey, nil) |
| 160 | } |
| 161 | recordPart = newYamlNodeWithKey(key, part, offset) |
| 162 | lines.Last = max(lines.Last, recordPart.Lines.Last) |
| 163 | case alertKey: |
| 164 | if alertPart != nil { |
| 165 | return duplicatedKeyError(lines, part.Line+offset, alertKey, nil) |
| 166 | } |
| 167 | alertPart = newYamlNodeWithKey(key, part, offset) |
| 168 | lines.Last = max(lines.Last, alertPart.Lines.Last) |
| 169 | case exprKey: |
| 170 | if exprPart != nil { |
| 171 | return duplicatedKeyError(lines, part.Line+offset, exprKey, nil) |
| 172 | } |
| 173 | exprPart = newPromQLExpr(key, part, offset) |
| 174 | lines.Last = max(lines.Last, exprPart.Value.Lines.Last) |
| 175 | case forKey: |
| 176 | if forPart != nil { |
| 177 | return duplicatedKeyError(lines, part.Line+offset, forKey, nil) |
| 178 | } |
| 179 | forPart = newYamlNodeWithKey(key, part, offset) |
| 180 | lines.Last = max(lines.Last, forPart.Lines.Last) |
| 181 | case labelsKey: |
| 182 | if labelsPart != nil { |
| 183 | return duplicatedKeyError(lines, part.Line+offset, labelsKey, nil) |
| 184 | } |
| 185 | labelsPart = newYamlMap(key, part, offset) |
| 186 | lines.Last = max(lines.Last, labelsPart.Lines.Last) |
| 187 | case annotationsKey: |
| 188 | if annotationsPart != nil { |
| 189 | return duplicatedKeyError(lines, part.Line+offset, annotationsKey, nil) |
| 190 | } |
| 191 | annotationsPart = newYamlMap(key, part, offset) |
| 192 | lines.Last = max(lines.Last, annotationsPart.Lines.Last) |
| 193 | |
| 194 | case keepFiringForKey: |
| 195 | if keepFiringForPart != nil { |
| 196 | return duplicatedKeyError(lines, part.Line+offset, keepFiringForKey, nil) |
| 197 | } |
| 198 | keepFiringForPart = newYamlNodeWithKey(key, part, offset) |
| 199 | lines.Last = max(lines.Last, keepFiringForPart.Lines.Last) |
| 200 | default: |
| 201 | unknownKeys = append(unknownKeys, key) |
| 202 | } |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | if exprPart != nil && exprPart.Value.Lines.First != exprPart.Value.Lines.Last { |
| 207 | contentLines := strings.Split(string(content), "\n") |
| 208 | for { |
| 209 | start := exprPart.Value.Lines.First |
| 210 | end := exprPart.Value.Lines.Last |
| 211 | if end > len(contentLines) { |
| 212 | end-- |
| 213 | } |
| 214 | input := strings.Join(contentLines[start:end], "") |
| 215 | input = strings.ReplaceAll(input, " ", "") |
| 216 | output := strings.ReplaceAll(exprPart.Value.Value, "\n", "") |
| 217 | output = strings.ReplaceAll(output, " ", "") |
| 218 | if end >= len(contentLines) { |
| 219 | break |
| 220 | } |
| 221 | if input == output { |
| 222 | break |
| 223 | } |
| 224 | exprPart.Value.Lines.Last = end + 1 |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | if recordPart != nil && alertPart != nil { |
| 229 | rule = Rule{ |
| 230 | Lines: lines, |
| 231 | Error: ParseError{ |
| 232 | Line: node.Line + offset, |
| 233 | Err: fmt.Errorf("got both %s and %s keys in a single rule", recordKey, alertKey), |
| 234 | }, |
| 235 | } |
| 236 | return rule, false, err |
| 237 | } |
| 238 | if exprPart != nil && alertPart == nil && recordPart == nil { |
| 239 | rule = Rule{ |
| 240 | Lines: lines, |
| 241 | Error: ParseError{ |
| 242 | Line: exprPart.Value.Lines.Last, |
| 243 | Err: fmt.Errorf("incomplete rule, no %s or %s key", alertKey, recordKey), |
| 244 | }, |
| 245 | } |
| 246 | return rule, false, err |
| 247 | } |
| 248 | if r, ok := ensureRequiredKeys(lines, recordKey, recordPart, exprPart); !ok { |
| 249 | return r, false, err |
| 250 | } |
| 251 | if r, ok := ensureRequiredKeys(lines, alertKey, alertPart, exprPart); !ok { |
| 252 | return r, false, err |
| 253 | } |
| 254 | if (recordPart != nil || alertPart != nil) && len(unknownKeys) > 0 { |
| 255 | var keys []string |
| 256 | for _, n := range unknownKeys { |
| 257 | keys = append(keys, n.Value) |
| 258 | } |
| 259 | rule = Rule{ |
| 260 | Lines: lines, |
| 261 | Error: ParseError{ |
| 262 | Line: unknownKeys[0].Line + offset, |
| 263 | Err: fmt.Errorf("invalid key(s) found: %s", strings.Join(keys, ", ")), |
| 264 | }, |
| 265 | } |
| 266 | return rule, false, err |
| 267 | } |
| 268 | |
| 269 | if recordPart != nil && exprPart != nil { |
| 270 | rule = Rule{ |
| 271 | Lines: lines, |
| 272 | RecordingRule: &RecordingRule{ |
| 273 | Record: *recordPart, |
| 274 | Expr: *exprPart, |
| 275 | Labels: labelsPart, |
| 276 | }, |
| 277 | Comments: ruleComments, |
| 278 | } |
| 279 | return rule, false, err |
| 280 | } |
| 281 | |
| 282 | if alertPart != nil && exprPart != nil { |
| 283 | rule = Rule{ |
| 284 | Lines: lines, |
| 285 | AlertingRule: &AlertingRule{ |
| 286 | Alert: *alertPart, |
| 287 | Expr: *exprPart, |
| 288 | For: forPart, |
| 289 | KeepFiringFor: keepFiringForPart, |
| 290 | Labels: labelsPart, |
| 291 | Annotations: annotationsPart, |
| 292 | }, |
| 293 | Comments: ruleComments, |
| 294 | } |
| 295 | return rule, false, err |
| 296 | } |
| 297 | |
| 298 | return rule, true, err |
| 299 | } |
| 300 | |
| 301 | func unpackNodes(node *yaml.Node) []*yaml.Node { |
| 302 | nodes := make([]*yaml.Node, 0, len(node.Content)) |
| 303 | var isMerge bool |
| 304 | for _, part := range node.Content { |
| 305 | if part.Tag == "!!merge" && part.Value == "<<" { |
| 306 | isMerge = true |
| 307 | } |
| 308 | |
| 309 | if part.Alias != nil { |
| 310 | if isMerge { |
| 311 | nodes = append(nodes, resolveMapAlias(part, node).Content...) |
| 312 | } else { |
| 313 | nodes = append(nodes, resolveMapAlias(part, part)) |
| 314 | } |
| 315 | isMerge = false |
| 316 | continue |
| 317 | } |
| 318 | if isMerge { |
| 319 | continue |
| 320 | } |
| 321 | nodes = append(nodes, part) |
| 322 | } |
| 323 | return nodes |
| 324 | } |
| 325 | |
| 326 | func nodeKeys(node *yaml.Node) (keys []string) { |
| 327 | if node.Kind != yaml.MappingNode { |
| 328 | return keys |
| 329 | } |
| 330 | for i, n := range node.Content { |
| 331 | if i%2 == 0 && n.Value != "" { |
| 332 | keys = append(keys, n.Value) |
| 333 | } |
| 334 | } |
| 335 | return keys |
| 336 | } |
| 337 | |
| 338 | func hasKey(node *yaml.Node, key string) bool { |
| 339 | for _, k := range nodeKeys(node) { |
| 340 | if k == key { |
| 341 | return true |
| 342 | } |
| 343 | } |
| 344 | return false |
| 345 | } |
| 346 | |
| 347 | func hasValue(node *YamlNode) bool { |
| 348 | if node == nil { |
| 349 | return false |
| 350 | } |
| 351 | return node.Value != "" |
| 352 | } |
| 353 | |
| 354 | func ensureRequiredKeys(lines LineRange, key string, keyVal *YamlNode, expr *PromQLExpr) (Rule, bool) { |
| 355 | if keyVal == nil { |
| 356 | return Rule{Lines: lines}, true |
| 357 | } |
| 358 | if !hasValue(keyVal) { |
| 359 | return Rule{ |
| 360 | Lines: lines, |
| 361 | Error: ParseError{ |
| 362 | Line: keyVal.Lines.Last, |
| 363 | Err: fmt.Errorf("%s value cannot be empty", key), |
| 364 | }, |
| 365 | }, false |
| 366 | } |
| 367 | if expr == nil { |
| 368 | return Rule{ |
| 369 | Lines: lines, |
| 370 | Error: ParseError{ |
| 371 | Line: keyVal.Lines.Last, |
| 372 | Err: fmt.Errorf("missing %s key", exprKey), |
| 373 | }, |
| 374 | }, false |
| 375 | } |
| 376 | if !hasValue(expr.Value) { |
| 377 | return Rule{ |
| 378 | Lines: lines, |
| 379 | Error: ParseError{ |
| 380 | Line: expr.Value.Lines.Last, |
| 381 | Err: fmt.Errorf("%s value cannot be empty", exprKey), |
| 382 | }, |
| 383 | }, false |
| 384 | } |
| 385 | return Rule{Lines: lines}, true |
| 386 | } |
| 387 | |
| 388 | func resolveMapAlias(part, parent *yaml.Node) *yaml.Node { |
| 389 | node := *part |
| 390 | node.Content = nil |
| 391 | var ok bool |
| 392 | for i, alias := range part.Alias.Content { |
| 393 | if i%2 == 0 { |
| 394 | ok = !hasKey(parent, alias.Value) |
| 395 | } |
| 396 | if ok { |
| 397 | node.Content = append(node.Content, alias) |
| 398 | } |
| 399 | if i%2 == 1 { |
| 400 | ok = false |
| 401 | } |
| 402 | } |
| 403 | return &node |
| 404 | } |
| 405 | |
| 406 | func duplicatedKeyError(lines LineRange, line int, key string, err error) (Rule, bool, error) { |
| 407 | rule := Rule{ |
| 408 | Lines: lines, |
| 409 | Error: ParseError{ |
| 410 | Line: line, |
| 411 | Err: fmt.Errorf("duplicated %s key", key), |
| 412 | }, |
| 413 | } |
| 414 | return rule, false, err |
| 415 | } |
| 416 | |