Missing support for /etc/resolver DNS resolution configuration on macOS

[pziggo]

The current version of the provider is built using Go version 1.19.4. With Go version < 1.20, Go is using the internal Go DNS resolver by default which only considers the file /etc/resolv.conf similar to glibc's behaviour. But macOS also supports additional configurations under /etc/resolver which is often used for local development to use proper name resolution.
The behaviour has been changed beginning with Go version 1.20 (see also golang/go#12524)

Upgrading the Go version used to build the provider, will solve this issue.

Terraform Version

$ terraform --version
Terraform v1.5.2
on darwin_amd64
...
+ provider registry.terraform.io/hashicorp/vault v3.17.0

Terraform Configuration Files

provider "vault" {
  address = "http://vault.minikube.test"
  ...
}

Debug Output

Resolver used if built with Go version 1.19.4

[DEBUG] provider.terraform-provider-vault: go package net: confVal.netCgo = false  netGo = true
[DEBUG] provider.terraform-provider-vault: go package net: built with netgo build tag; using Go's DNS resolver
[DEBUG] provider.terraform-provider-vault: go package net: hostLookupOrder(vault.minikube.test) = files,dns

Resolver used if built with Go version 1.20.6

[DEBUG] provider.terraform-provider-vault: go package net: confVal.netCgo = false  netGo = false
[DEBUG] provider.terraform-provider-vault: go package net: using cgo DNS resolver
[DEBUG] provider.terraform-provider-vault: go package net: hostLookupOrder(vault.minikube.test) = cgo

Expected Behavior

The provider should lookup the host address using cgo DNS resolver on macOS in order to correctly resolve the address with the local resolver.

Actual Behavior

The provider is using Go's DNS resolver and thus fails to resolve the local host:

│ Error: failed to lookup token, err=Get "http://vault.minikube.test/v1/auth/token/lookup-self": dial tcp: lookup vault.minikube.test on 192.168.178.1:53: no such host
│ 
│   with provider["registry.terraform.io/hashicorp/vault"],
│   on provider.tf line 31, in provider "vault":
│   31: provider "vault" {
│ 

... while the name resolution actually works with other utils:

$ dscacheutil -q host -a name vault.minikube.test
name: vault.minikube.test
ip_address: 192.168.64.18

Steps to Reproduce

1. Start minikube with addon ingress-dns on macOS
2. Create a vault application using a custom ingress configuration with a local host configured
3. Configure a custom domain resolution configuration under /etc/resolver
4. Try to connect to the vault instance with the previously configured hostname

References

• net: Support the /etc/resolver DNS resolution configuration hierarchy on OS X when cgo is disabled golang/go#12524
• https://go-review.googlesource.com/c/go/+/446178
• DNS resolution issues when connected to a VPN terraform#3536
• provider DNS failure on macOS on VPN terraform-provider-consul#283
• Compile release binaries with CGO_ENABLED=1 for macos DNS resolution terraform-provider-kubernetes#969