Add support for NodeBalancers UDP

[lgarber-akamai]

📝 Description

This pull request adds support for UDP NodeBalancer configs as well as the corresponding tests.

✔️ How to Test

The following test steps assume you have pulled down this PR locally.

NOTE: See the comments of TPT-3375 for instructions on configuring your account for UDP NodeBalancers.

Unit Testing

make testunit

Integration Testing

make ARGS="-run TestNodeBalancer" fixtures

Manual Testing

1. In a linodego sandbox environment (e.g. linodego), run the following:

package main

import (
	"context"
	"log"
	"os"

	"github.com/linode/linodego"

	"github.com/davecgh/go-spew/spew"
)

func main() {
	client := linodego.NewClient(nil)
	client.SetToken(os.Getenv("LINODE_TOKEN"))
	client.SetAPIVersion("v4beta")

	nodebalancer, err := client.CreateNodeBalancer(
		context.Background(),
		linodego.NodeBalancerCreateOptions{
			Label:              linodego.Pointer("linodego-test-nb"),
			Region:             "us-mia",
			ClientConnThrottle: linodego.Pointer(5),
		},
	)
	if err != nil {
		log.Fatal(err)
	}

	spew.Dump(nodebalancer)

	config, err := client.CreateNodeBalancerConfig(
		context.Background(),
		nodebalancer.ID,
		linodego.NodeBalancerConfigCreateOptions{
			Port:          1234,
			Protocol:      linodego.ProtocolUDP,
			UDPCheckPort:  linodego.Pointer(4321),
			Algorithm:     linodego.AlgorithmRingHash,
			CheckInterval: 60,
		},
	)
	if err != nil {
		log.Fatal(err)
	}

	spew.Dump(config)
}

2. Ensure the output looks similar to the following:

(*linodego.NodeBalancer)(0x1400018c1b0)({
 ID: (int) 1176274,
 Label: (*string)(0x14000010140)((len=16) "linodego-test-nb"),
 Region: (string) (len=6) "us-mia",
 Hostname: (*string)(0x14000010150)((len=40) "172-233-167-150.ip.linodeusercontent.com"),
 IPv4: (*string)(0x14000010160)((len=15) "172.233.167.150"),
 IPv6: (*string)(0x14000010170)((len=22) "2a01:7e04:1::ace9:a796"),
 ClientConnThrottle: (int) 5,
 ClientUDPSessThrottle: (int) 0,
 Transfer: (linodego.NodeBalancerTransfer) {
  Total: (*float64)(<nil>),
  Out: (*float64)(<nil>),
  In: (*float64)(<nil>)
 },
 Tags: ([]string) {
 },
 Created: (*time.Time)(0x1400000c120)(2025-01-07 16:28:14 +0000 UTC),
 Updated: (*time.Time)(0x1400000c138)(2025-01-07 16:28:14 +0000 UTC)
})

(*linodego.NodeBalancerConfig)(0x14000000360)({
 ID: (int) 1941508,
 Port: (int) 1234,
 Protocol: (linodego.ConfigProtocol) (len=3) "udp",
 ProxyProtocol: (linodego.ConfigProxyProtocol) (len=4) "none",
 Algorithm: (linodego.ConfigAlgorithm) (len=9) "ring_hash",
 Stickiness: (linodego.ConfigStickiness) (len=7) "session",
 Check: (linodego.ConfigCheck) (len=4) "none",
 CheckInterval: (int) 60,
 CheckAttempts: (int) 3,
 CheckPath: (string) "",
 CheckBody: (string) "",
 CheckPassive: (bool) false,
 CheckTimeout: (int) 30,
 UDPCheckPort: (int) 4321,
 UDPSessionTimeout: (int) 16,
 CipherSuite: (linodego.ConfigCipher) (len=4) "none",
 NodeBalancerID: (int) 1176274,
 SSLCommonName: (string) "",
 SSLFingerprint: (string) "",
 SSLCert: (string) "",
 SSLKey: (string) "",
 NodesStatus: (*linodego.NodeBalancerNodeStatus)(0x1400000f050)({
  Up: (int) 0,
  Down: (int) 0
 })
})

[lgarber-akamai]

These changes were made implicitly by gofumpt -l -w .

[ykim-akamai]

LGTM, everything works well locally. Great work!