fix(server): migration to explicit primary IPs fails

[apricote]

When migrating a server from the previously used implicit primary IPs to using the hcloud_primary_ip resources and specifying those in the hcloud_server.public_net argument failed, because the state for the public_net was not correctly populated. This caused the servers to require an unnecessary re-attach of the primary ips.

Fixes #577

[github-actions]

This PR has been marked as stale because it has not had recent activity. The bot will close the PR if no further action occurs.

[apricote]

Closing as I have not managed to fix the bugs that came with my changes. This will be easier to implement after #752

[apricote]

A more robust implementation of publicNetToTerraformPublicNet that avoids empty sets:

func publicNetToTerraformPublicNet(publicNet hcloud.ServerPublicNet) map[string]interface{} {
	tfPublicNet := make(map[string]interface{})

	ipv4Enabled := !publicNet.IPv4.IsUnspecified()
	tfPublicNet["ipv4_enabled"] = ipv4Enabled
	if ipv4Enabled {
		tfPublicNet["ipv4"] = publicNet.IPv4.ID
	}

	ipv6Enabled := !publicNet.IPv6.IsUnspecified()
	tfPublicNet["ipv6_enabled"] = ipv6Enabled
	if ipv6Enabled {
		tfPublicNet["ipv6"] = publicNet.IPv6.ID
	}

	return tfPublicNet
}

[apricote]

Adding computed: true to the attribute causes issues with the transition from an explicitly defined public_net to a removed public_net.

• when the user removes the public_net block, the default should be restored. The default is generated random IPv4 and IPv6
• if we mark the field as computed, Terraform will not mark the fields as changed and keep the values we previously wrote to the state.
• Because of this, we can not detect that the user has removed the attribute, and can not trigger the logic to generate random IPs

This can only be solved by the plugin framework, which gives us access to the precise configuration that the user specified: https://pkg.go.dev/github.com/hashicorp/terraform-plugin-framework/resource#UpdateRequest

[jooola]

Reopening as the issue is still relevant, we are just being blocked by the migration to the plugin framework.

[jooola]

Nevermind, I thought it was an issue, not a PR.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 19 lines in your changes missing coverage. Please review.

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Files with missing lines	Patch %	Lines
internal/server/resource.go	0.00%	19 Missing ⚠️

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