alexandra vargas
50 lines
1.3 KiB
Go
50 lines
1.3 KiB
Go
package prometheus
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import (
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"fmt"
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"github.com/prometheus/prometheus/promql/parser"
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)
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// Parser extracts metric names from PromQL queries
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type Parser struct{}
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// NewParser creates a new PromQL parser
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func NewParser() *Parser {
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return &Parser{}
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}
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// ExtractMetrics parses a PromQL query and extracts all metric names
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// For example: "rate(http_requests_total[5m])" returns ["http_requests_total"]
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func (p *Parser) ExtractMetrics(query string) ([]string, error) {
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// Parse the PromQL expression
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expr, err := parser.ParseExpr(query)
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if err != nil {
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return nil, fmt.Errorf("failed to parse PromQL query: %w", err)
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}
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// Extract metric names by walking the AST
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metrics := make(map[string]bool) // Use map to deduplicate
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parser.Inspect(expr, func(node parser.Node, _ []parser.Node) error {
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// VectorSelector represents a metric selector like "up" or "up{job="foo"}"
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if vs, ok := node.(*parser.VectorSelector); ok {
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metrics[vs.Name] = true
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}
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// MatrixSelector represents range queries like "up[5m]"
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if ms, ok := node.(*parser.MatrixSelector); ok {
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if vs, ok := ms.VectorSelector.(*parser.VectorSelector); ok {
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metrics[vs.Name] = true
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}
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}
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return nil
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})
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// Convert map to slice
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result := make([]string, 0, len(metrics))
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for metric := range metrics {
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result = append(result, metric)
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}
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return result, nil
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}
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