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