Remove unnecessary detach logic from Nic

Detach nic from the VM logic is not needed since we do not support
managing nics, yet. There is no need to keep it.

I have also moved the cleanup of tunnels to the
association_dependencies.

Furthermore, since we do not bud any child processes anymore, we do not
need to destroy child progs separately at the time of nic destroy.

model/nic.rb

@@ -8,9 +8,12 @@ class Nic < Sequel::Model
  one_to_many :src_ipsec_tunnels, key: :src_nic_id, class: IpsecTunnel
  one_to_many :dst_ipsec_tunnels, key: :dst_nic_id, class: IpsecTunnel
  one_to_one :strand, key: :id, class: Strand
+ plugin :association_dependencies, src_ipsec_tunnels: :destroy, dst_ipsec_tunnels: :destroy
+
  include ResourceMethods
  include SemaphoreMethods
- semaphore :destroy, :detach_vm, :start_rekey, :trigger_outbound_update,
+
+ semaphore :destroy, :start_rekey, :trigger_outbound_update,
  :old_state_drop_trigger, :setup_nic, :repopulate
 
  plugin :column_encryption do |enc|

prog/vnet/nic_nexus.rb

@@ -2,7 +2,7 @@
 
 class Prog::Vnet::NicNexus < Prog::Base
  subject_is :nic
- semaphore :destroy, :detach_vm, :start_rekey, :trigger_outbound_update, :old_state_drop_trigger, :setup_nic, :repopulate
+ semaphore :destroy, :start_rekey, :trigger_outbound_update, :old_state_drop_trigger, :setup_nic, :repopulate
 
  def self.assemble(private_subnet_id, name: nil, ipv6_addr: nil, ipv4_addr: nil)
  unless (subnet = PrivateSubnet[private_subnet_id])
@@ -51,10 +51,6 @@ def before_run
  end
 
  label def wait
- when_detach_vm_set? do
- hop_detach_vm
- end
-
  when_repopulate_set? do
  hop_repopulate
  end
@@ -120,32 +116,13 @@ def before_run
  end
 
  decr_destroy
- strand.children.each { _1.destroy }
-
- DB.transaction do
- nic.src_ipsec_tunnels_dataset.destroy
- nic.dst_ipsec_tunnels_dataset.destroy
- nic.private_subnet.incr_refresh_keys
 
-  nic.destroy
- end
+ nic.private_subnet.incr_refresh_keys
+ nic.destroy
 
  pop "nic deleted"
  end
 
- label def detach_vm
- DB.transaction do
- nic.update(vm_id: nil)
- nic.src_ipsec_tunnels_dataset.destroy
- nic.dst_ipsec_tunnels_dataset.destroy
- nic.private_subnet.incr_refresh_keys
- strand.children.map { _1.destroy }
- decr_detach_vm
- end
-
- hop_wait
- end
-
  # Generate a MAC with the "local" (generated, non-manufacturer) bit
  # set and the multicast bit cleared in the first octet.
  #

spec/prog/vnet/nic_nexus_spec.rb

@@ -127,11 +127,6 @@
  expect { nx.wait }.to nap(30)
  end
 
- it "hops to detach vm if needed" do
- expect(nx).to receive(:when_detach_vm_set?).and_yield
- expect { nx.wait }.to hop("detach_vm")
- end
-
  it "hops to start rekey if needed" do
  expect(nx).to receive(:when_start_rekey_set?).and_yield
  expect { nx.wait }.to hop("start_rekey")
@@ -241,10 +236,6 @@
  end
 
  it "destroys nic" do
- expect(ipsec_tunnels[0]).to receive(:destroy).and_return(true)
- expect(ipsec_tunnels[1]).to receive(:destroy).and_return(true)
- expect(nic).to receive(:src_ipsec_tunnels_dataset).and_return(ipsec_tunnels[0])
- expect(nic).to receive(:dst_ipsec_tunnels_dataset).and_return(ipsec_tunnels[1])
  expect(nic).to receive(:private_subnet).and_return(ps)
  expect(ps).to receive(:incr_refresh_keys).and_return(true)
  expect(nic).to receive(:destroy).and_return(true)
@@ -257,44 +248,6 @@
  end
  end
 
- describe "#detach_vm" do
- let(:ps) {
- PrivateSubnet.create_with_id(name: "ps", location: "hetzner-hel1", net6: "fd10:9b0b:6b4b:8fbb::/64",
- net4: "1.1.1.0/26", state: "waiting").tap { _1.id = "57afa8a7-2357-4012-9632-07fbe13a3133" }
- }
- let(:nic) {
- Nic.new(private_subnet_id: ps.id,
- private_ipv6: "fd10:9b0b:6b4b:8fbb:abc::",
- private_ipv4: "10.0.0.1",
- mac: "00:00:00:00:00:00",
- encryption_key: "0x736f6d655f656e6372797074696f6e5f6b6579",
- name: "default-nic").tap { _1.id = "0a9a166c-e7e7-4447-ab29-7ea442b5bb0e" }
- }
- let(:ipsec_tunnels) {
- [
- instance_double(IpsecTunnel),
- instance_double(IpsecTunnel)
- ]
- }
-
- before do
- allow(nx).to receive(:nic).and_return(nic)
- end
-
- it "detaches vm and refreshes mesh" do
- expect(nic).to receive(:update).with(vm_id: nil).and_return(true)
- expect(nic).to receive(:src_ipsec_tunnels_dataset).and_return(ipsec_tunnels[0])
- expect(ipsec_tunnels[0]).to receive(:destroy).and_return(true)
- expect(nic).to receive(:dst_ipsec_tunnels_dataset).and_return(ipsec_tunnels[1])
- expect(ipsec_tunnels[1]).to receive(:destroy).and_return(true)
-
- expect(nic).to receive(:private_subnet).and_return(ps)
- expect(ps).to receive(:incr_refresh_keys).and_return(true)
-
- expect { nx.detach_vm }.to hop("wait")
- end
- end
-
  describe "nic fetch" do
  let(:nic) {
  Nic.new(private_subnet_id: ps.id,