SuggestedDashboards- Extend dashvalidator POC: Prometheus validator

apps/dashvalidator/pkg/validator/prometheus/parser.go

@@ -0,0 +1,49 @@
+package prometheus
+
+import (
+	"fmt"
+
+	"github.com/prometheus/prometheus/promql/parser"
+)
+
+// Parser extracts metric names from PromQL queries
+type Parser struct{}
+
+// NewParser creates a new PromQL parser
+func NewParser() *Parser {
+	return &Parser{}
+}
+
+// ExtractMetrics parses a PromQL query and extracts all metric names
+// For example: "rate(http_requests_total[5m])" returns ["http_requests_total"]
+func (p *Parser) ExtractMetrics(query string) ([]string, error) {
+	// Parse the PromQL expression
+	expr, err := parser.ParseExpr(query)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse PromQL query: %w", err)
+	}
+
+	// Extract metric names by walking the AST
+	metrics := make(map[string]bool) // Use map to deduplicate
+	parser.Inspect(expr, func(node parser.Node, _ []parser.Node) error {
+		// VectorSelector represents a metric selector like "up" or "up{job="foo"}"
+		if vs, ok := node.(*parser.VectorSelector); ok {
+			metrics[vs.Name] = true
+		}
+		// MatrixSelector represents range queries like "up[5m]"
+		if ms, ok := node.(*parser.MatrixSelector); ok {
+			if vs, ok := ms.VectorSelector.(*parser.VectorSelector); ok {
+				metrics[vs.Name] = true
+			}
+		}
+		return nil
+	})
+
+	// Convert map to slice
+	result := make([]string, 0, len(metrics))
+	for metric := range metrics {
+		result = append(result, metric)
+	}
+
+	return result, nil
+}