Need to be able to skip TLS verification

[xgattuso]

Hello,

I wanted to suggest a PR but apparently I'm unable to. So suggesting here the changes.

Thanks for this lib by the way!

It fixes two things: one is the port type. To prevent, during autodetection, to end up with the following error:

dial tcp: lookup tcp/⋹: Servname not supported for ai_socktype

The right type is required.

It fixes this bug: optix2000/nsd_exporter#5

The other change is about to give the ability to set skipTLSverify. nsd_exporter will be patched accordingly.

# ./nsd_exporter
2024/12/17 13:16:46 tls: failed to verify certificate: x509: certificate relies on legacy Common Name field, use SANs instead
# ./nsd_exporter -skipTLSverify
2024/12/17 13:16:49 Started.

Being aware that the latter is a breaking change it might maybe deserve a v2.0.0. Let me know how do you want to proceed (split PR, won't be implemented...).

Here is my diff.

$ git diff origin/HEAD..skipTLSverify 
diff --git a/nsdctl.go b/nsdctl.go
index 2ae122e..9e805a4 100644
--- a/nsdctl.go
+++ b/nsdctl.go
@@ -116,7 +116,7 @@ type NSDClient struct {
 }
 
 // NewClientFromConfig tries to autodetect and create a new NSDClient from an config file
-func NewClientFromConfig(configPath string) (*NSDClient, error) {
+func NewClientFromConfig(configPath string, skipTLSverify bool) (*NSDClient, error) {
        filename := path.Base(configPath)
 
        var detectedType string
@@ -189,10 +189,10 @@ func NewClientFromConfig(configPath string) (*NSDClient, error) {
        }
 
        if port != 0 {
-               hostString = "127.0.0.1:" + string(port)
+               hostString = "127.0.0.1:" + strconv.FormatUint(uint64(port), 10)
        }
 
-       return NewClient(detectedType, hostString, caFile, keyFile, certFile, false)
+       return NewClient(detectedType, hostString, caFile, keyFile, certFile, skipTLSverify)
 }
 
 // NewClient creates a complete new NSDClient and returns any errors encountered