Add ASN to logtail, collector, aggregator, frontend and CLI

cmd/frontend/filter.go

@@ -126,8 +126,20 @@ func applyTerm(term string, fs *filterState) error {
 		} else {
 			fs.IsTor = "0"
 		}
+	case "asn":
+		if op == "~=" {
+			return fmt.Errorf("asn does not support ~=; use =, !=, >=, >, <=, <")
+		}
+		expr := op + value
+		if op == "=" {
+			expr = value
+		}
+		if _, _, ok := st.ParseStatusExpr(expr); !ok {
+			return fmt.Errorf("invalid asn expression %q", expr)
+		}
+		fs.ASN = expr
 	default:
-		return fmt.Errorf("unknown field %q; valid: status, website, uri, prefix, is_tor", field)
+		return fmt.Errorf("unknown field %q; valid: status, website, uri, prefix, is_tor, asn", field)
 	}
 	return nil
 }
@@ -167,9 +179,24 @@ func FilterExprString(f filterState) string {
 	if f.IsTor != "" {
 		parts = append(parts, "is_tor="+f.IsTor)
 	}
+	if f.ASN != "" {
+		parts = append(parts, asnTermStr(f.ASN))
+	}
 	return strings.Join(parts, " AND ")
 }
 
+// asnTermStr converts a stored ASN expression (">=1000", "12345") to a
+// full filter term ("asn>=1000", "asn=12345").
+func asnTermStr(expr string) string {
+	if expr == "" {
+		return ""
+	}
+	if len(expr) > 0 && (expr[0] == '!' || expr[0] == '>' || expr[0] == '<') {
+		return "asn" + expr
+	}
+	return "asn=" + expr
+}
+
 // statusTermStr converts a stored status expression (">=400", "200") to a
 // full filter term ("status>=400", "status=200").
 func statusTermStr(expr string) string {