-A ISTIO_INBOUND -p tcp --dport 15090 -j RETURN
-A ISTIO_INBOUND -p tcp -m conntrack --ctstate RELATED,ESTABLISHED -j ISTIO_DIVERT
-A ISTIO_INBOUND -p tcp -j ISTIO_TPROXY
-A PREROUTING -p tcp -m mark --mark 1337 -j CONNMARK --save-mark
-A OUTPUT -p tcp -o lo -m mark --mark 1337 -j RETURN
-A OUTPUT ! -d 127.0.0.1/32 -p tcp -o lo -m owner --uid-owner 1000670000 -j MARK --set-mark 1338

lint-markdown:
	@${FINDFILES} -name '*.md' -print0 | ${XARGS} mdl --ignore-front-matter --style common/config/mdl.rb

lint-links:
	@${FINDFILES} -name '*.md' -print0 | ${XARGS} awesome_bot --skip-save-results --allow_ssl --allow-timeout --allow-dupe --allow-redirect --white-list ${MARKDOWN_LINT_ALLOWLIST}

lint-sass:
	@${FINDFILES} -name '*.scss' -print0 | ${XARGS} sass-lint -c common/config/sass-lint.yml --verbose

- `istio-iptables`
    - sets up iptables to redirect a list of ports to the port envoy will listen
    - shared code with istio-init container
    - it will generate an iptables-save config, based on annotations/labels and other settings, and apply it.

### CmdAdd Sidecar Workflow

`CmdAdd` is triggered when there is a new pod created. This runs on the node, in a chain of CNI plugins - Istio is

-A ISTIO_INBOUND -p tcp --dport 15090 -j RETURN
-A ISTIO_INBOUND -p tcp -m conntrack --ctstate RELATED,ESTABLISHED -j ISTIO_DIVERT
-A ISTIO_INBOUND -p tcp -j ISTIO_TPROXY
-A PREROUTING -p tcp -m mark --mark 1337 -j CONNMARK --save-mark
-A OUTPUT -p tcp -o lo -m mark --mark 1337 -j RETURN
-A OUTPUT ! -d 127.0.0.1/32 -p tcp -o lo -m owner --uid-owner 1337 -j MARK --set-mark 1338

	so that we can remove stale entries when the ztunnel pod is deleted
	or when the ztunnel pod is restarted in the same pod (remove old entries when the same uid connects again, but with different boot id?)

	save a queue of what needs to be sent to the ztunnel pod and send it one by one when it connects.

	when a new ztunnel connects with different uid, only propagate deletes to older ztunnels.
*/

type connMgr struct {

message GroupVersionForDiscovery {
  // groupVersion specifies the API group and version in the form "group/version"
  optional string groupVersion = 1;

  // version specifies the version in the form of "version". This is to save
  // the clients the trouble of splitting the GroupVersion.
  optional string version = 2;
}

// GroupVersionKind unambiguously identifies a kind.  It doesn't anonymously include GroupVersion

	/*
		for each process, find its netns inode,
		if we already seen the inode, skip it
		if we haven't seen the inode, check the process cgroup and see if we
		can extract a pod uid from it.
		if we can, open the netns, and save a map of uid->netns-fd
	*/

	podUIDNetns := make(PodToNetns)
	netnsObserved := sets.New[uint64]()

	entries, err := fs.ReadDir(p.proc, ".")
	if err != nil {
		return nil, err
	}