Use ioutil.ReadFile which existed on older go versions.

Author: scr-oath

.github/workflows/ci.yaml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: ['1.14', '1.15', '1.16', '1.17', '1.18']
+        go: ['1.14', '1.15', '1.16', '1.17', '1.18', '1.19']
 
     services: {}
     steps:

http/api_test.go

@@ -14,7 +14,6 @@ import (
 	"log"
 	"net/http"
 	"net/http/httptest"
-	"os"
 	"strings"
 	"testing"
 	"time"
@@ -233,7 +232,7 @@ func TestMTLS(t *testing.T) {
 	defer s.Close()
 	serverCert, err := tls.LoadX509KeyPair("test/data/test.cert.pem", "test/data/test.key.pem")
 	require.NoError(t, err)
-	caData, err := os.ReadFile("test/data/test.cert.pem")
+	caData, err := ioutil.ReadFile("test/data/test.cert.pem")
 	require.NoError(t, err)
 	cas := x509.NewCertPool()
 	cas.AppendCertsFromPEM(caData)

http/client/client.go

@@ -4,6 +4,7 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"encoding/json"
+	"io/ioutil"
 	"log"
 	"net/http"
 	"net/http/cookiejar"
@@ -163,7 +164,7 @@ func New(L *lua.LState) int {
 			// parse root_cas
 			case `root_cas_pem_file`:
 				if value, ok := v.(lua.LString); ok {
-					pemData, err := os.ReadFile(string(value))
+					pemData, err := ioutil.ReadFile(string(value))
 					if err != nil {
 						L.RaiseError("error loading root_cas_pem_file from %s: %v", value, err)
 					}