metricsql.py

README.md

python wrapper for metricsql expr validation.

usage:

1. build shared lib: go build -buildmode=c-shared -o library.so main.go
2. use it

python3 metricsql.py 'not_exist(up)'`
failed to parse expr: not_exist(up), error: unsupported function "not_exist"

python3 metricsql.py 'rate(up) > 1'
expr: rate(up) > 1 is valid

NOTE result of parseExpr doesn't free memory, so it's recommened to use only for ad-hoc valition.

go.mod

module example.com/metricsqlpy

go 1.21.0

require (
	github.com/VictoriaMetrics/metrics v1.24.0 // indirect
	github.com/VictoriaMetrics/metricsql v0.70.0 // indirect
	github.com/valyala/fastrand v1.1.0 // indirect
	github.com/valyala/histogram v1.2.0 // indirect
	golang.org/x/sys v0.10.0 // indirect
)

main.go

package main

import (
	"C"

	"github.com/VictoriaMetrics/metricsql"
)

//export parseExpr
func parseExpr(expr *C.char) *C.char {
	exprStr := C.GoString(expr)
  _, err := metricsql.Parse(exprStr)
  if err != nil {
    return C.CString(err.Error())
  }
  return C.CString("")
}

func main(){}

metricsql.py

import ctypes
import sys
metricsql = ctypes.cdll.LoadLibrary('./library.so')

validateExpr = sys.argv[1]

metricsql.parseExpr.restype = ctypes.c_char_p
metricsql.parseExpr.argtypes = [
    ctypes.c_char_p
]
result = metricsql.parseExpr(validateExpr.encode())
if len(result) > 0:
    print(f"failed to parse expr: {validateExpr}, error: {result.decode()}", )
    exit(1)

print(f"expr: {validateExpr} is valid")