[Bug]: unable to empty ip_ranges for VPC interface once set

[rahulait]

go Version

go version go1.21.7 linux/amd64

API Wrapper Version

github.com/linode/linodego v1.29.0

Code Snippet

package main

import (
	"context"
	"fmt"

	"github.com/linode/linodego"
	"golang.org/x/oauth2"

	"log"
	"net/http"
	"os"
)

func main() {
	apiKey, ok := os.LookupEnv("LINODE_TOKEN")
	if !ok {
		log.Fatal("Could not find LINODE_TOKEN, please assert it is set.")
	}
	tokenSource := oauth2.StaticTokenSource(&oauth2.Token{AccessToken: apiKey})

	oauth2Client := &http.Client{
		Transport: &oauth2.Transport{
			Source: tokenSource,
		},
	}

	linodeClient := linodego.NewClient(oauth2Client)
	linodeClient.SetDebug(true)

	// Get instance configs
	instance, _ := linodeClient.GetInstance(context.Background(), 55519453)
	configs, err := linodeClient.ListInstanceConfigs(context.Background(), instance.ID, &linodego.ListOptions{})
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%v", configs[0].Interfaces)

	// Try clearing ip_ranges
	interfaceUpdateOptions := linodego.InstanceConfigInterfaceUpdateOptions{
		IPRanges: []string{},
	}

	// Set empty ip_ranges for VPC interface
	for _, iface := range configs[0].Interfaces {
		if iface.VPCID != nil && iface.IPv4.VPC != "" {
			resp, err := linodeClient.UpdateInstanceConfigInterface(context.Background(), instance.ID, configs[0].ID, iface.ID, interfaceUpdateOptions)
			if err != nil {
				log.Fatal(err)
			}
			fmt.Printf("Deleted routes. New output: %v", resp)
			if len(resp.IPRanges) > 0 {
				log.Printf("\nFailed to empty ip_ranges")
			}
		}
	}
}

Expected Behavior

ip_ranges should be set to empty:

{
   "ip_ranges": []
}

Actual Behavior

ip_ranges of interface connected to VPC never gets cleared.

Output sample:

Initial instance state:

==============================================================================
2024/03/02 05:23:05.324915 DEBUG RESTY 
==============================================================================
~~~ REQUEST ~~~
GET  /v4/linode/instances/55519453/configs  HTTP/1.1
HOST   : api.linode.com
HEADERS:
        Accept: application/json
        Content-Type: application/json
        User-Agent: linodego/v1.29.0 https://github.com/linode/linodego
BODY   :
***** NO CONTENT *****
------------------------------------------------------------------------------
~~~ RESPONSE ~~~
STATUS       : 200 OK
PROTO        : HTTP/1.1
RECEIVED AT  : 2024-03-02T05:23:05.324753224Z
TIME DURATION: 126.797914ms
BODY         :
{
   "data": [
      {
         "id": 58641324,
         "label": "My Ubuntu 22.04 LTS Disk Profile",
         "helpers": {
            "updatedb_disabled": true,
            "distro": true,
            "modules_dep": true,
            "network": true,
            "devtmpfs_automount": true
         },
         "kernel": "linode/grub2",
         "comments": "",
         "memory_limit": 0,
         "created": "2024-03-01T19:14:27",
         "updated": "2024-03-01T19:14:27",
         "root_device": "/dev/sda",
         "devices": {
            "sda": {
               "disk_id": 109845040,
               "volume_id": null
            },
            "sdb": {
               "disk_id": 109845041,
               "volume_id": null
            },
            "sdc": null,
            "sdd": null,
            "sde": null,
            "sdf": null,
            "sdg": null,
            "sdh": null
         },
         "initrd": null,
         "run_level": "default",
         "virt_mode": "paravirt",
         "interfaces": [
            {
               "id": 1137088,
               "purpose": "public",
               "primary": true,
               "active": true,
               "ipam_address": null,
               "label": null,
               "vpc_id": null,
               "subnet_id": null,
               "ipv4": null,
               "ipv6": null,
               "ip_ranges": null
            },
            {
               "id": 1137089,
               "purpose": "vpc",
               "primary": false,
               "active": true,
               "ipam_address": null,
               "label": null,
               "vpc_id": 26186,
               "subnet_id": 26443,
               "ipv4": {
                  "vpc": "10.0.0.5",
                  "nat_1_1": null
               },
               "ipv6": null,
               "ip_ranges": [
                  "10.192.3.0/24"
               ]
            }
         ]
      }
   ],
   "page": 1,
   "pages": 1,
   "results": 1
}

Logs of request sent to set ip_ranges to empty:

==============================================================================
~~~ REQUEST ~~~
PUT  /v4/linode/instances/55519453/configs/58641324/interfaces/1137089  HTTP/1.1
HOST   : api.linode.com
HEADERS:
        Accept: application/json
        Content-Type: application/json
        User-Agent: linodego/v1.29.0 https://github.com/linode/linodego
BODY   :
{}
------------------------------------------------------------------------------
~~~ RESPONSE ~~~
STATUS       : 200 OK
PROTO        : HTTP/1.1
RECEIVED AT  : 2024-03-02T05:23:05.495718273Z
TIME DURATION: 170.160593ms
BODY         :
{
   "id": 1137089,
   "purpose": "vpc",
   "primary": false,
   "active": true,
   "ipam_address": null,
   "label": null,
   "vpc_id": 26186,
   "subnet_id": 26443,
   "ipv4": {
      "vpc": "10.0.0.5",
      "nat_1_1": null
   },
   "ipv6": null,
   "ip_ranges": [
      "10.192.3.0/24"
   ]
}

Ideally, in the end when we call linodeClient.UpdateInstanceConfigInterface() with empty ip_ranges, it should have set ip_ranges to empty and response should not contain ip_ranges still set.

I can delete an item from ip_ranges if there are more than 1 entries, its just that I am unable to set it to empty.

Steps to Reproduce

1. Bring up a linode in VPC.
2. Try setting ip_ranges for the VPC interface.
3. Once set, try clearing the ip_ranges.

If one has a linode in VPC, they can use the above script to reproduce the issue. Just change the instance id with your instance id and set atleast one ip subnet in ip_ranges.

[lgarber-akamai]

Thank you for the bug report!

It looks like omitempty is excluding explicitly empty list values from the interface update request body.

I've created a ticket in our internal tracker to correct this functionality and will let you know once it's been resolved 🙂