2 Commits (e11ff284435d3789136e583b82c4e416f6c7f925)

Author	SHA1	Message	Date
Irbe Krumina	b406f209c3	cmd/{k8s-operator,containerboot},kube: ensure egress ProxyGroup proxies don't terminate while cluster traffic is still routed to them (#14436) ... cmd/{containerboot,k8s-operator},kube: add preshutdown hook for egress PG proxies This change is part of work towards minimizing downtime during update rollouts of egress ProxyGroup replicas. This change: - updates the containerboot health check logic to return Pod IP in headers, if set - always runs the health check for egress PG proxies - updates ClusterIP Services created for PG egress endpoints to include the health check endpoint - implements preshutdown endpoint in proxies. The preshutdown endpoint logic waits till, for all currently configured egress services, the ClusterIP Service health check endpoint is no longer returned by the shutting-down Pod (by looking at the new Pod IP header). - ensures that kubelet is configured to call the preshutdown endpoint This reduces the possibility that, as replicas are terminated during an update, a replica gets terminated to which cluster traffic is still being routed via the ClusterIP Service because kube proxy has not yet updated routig rules. This is not a perfect check as in practice, it only checks that the kube proxy on the node on which the proxy runs has updated rules. However, overall this might be good enough. The preshutdown logic is disabled if users have configured a custom health check port via TS_LOCAL_ADDR_PORT env var. This change throws a warnign if so and in future setting of that env var for operator proxies might be disallowed (as users shouldn't need to configure this for a Pod directly). This is backwards compatible with earlier proxy versions. Updates tailscale/tailscale#14326 Signed-off-by: Irbe Krumina <irbe@tailscale.com>	1 year ago
Irbe Krumina	096b090caf	cmd/containerboot,kube,util/linuxfw: configure kube egress proxies to route to 1+ tailnet targets (#13531) ... * cmd/containerboot,kube,util/linuxfw: configure kube egress proxies to route to 1+ tailnet targets This commit is first part of the work to allow running multiple replicas of the Kubernetes operator egress proxies per tailnet service + to allow exposing multiple tailnet services via each proxy replica. This expands the existing iptables/nftables-based proxy configuration mechanism. A proxy can now be configured to route to one or more tailnet targets via a (mounted) config file that, for each tailnet target, specifies: - the target's tailnet IP or FQDN - mappings of container ports to which cluster workloads will send traffic to tailnet target ports where the traffic should be forwarded. Example configfile contents: { "some-svc": {"tailnetTarget":{"fqdn":"foo.tailnetxyz.ts.net","ports"{"tcp:4006:80":{"protocol":"tcp","matchPort":4006,"targetPort":80},"tcp:4007:443":{"protocol":"tcp","matchPort":4007,"targetPort":443}}}} } A proxy that is configured with this config file will configure firewall rules to route cluster traffic to the tailnet targets. It will then watch the config file for updates as well as monitor relevant netmap updates and reconfigure firewall as needed. This adds a bunch of new iptables/nftables functionality to make it easier to dynamically update the firewall rules without needing to restart the proxy Pod as well as to make it easier to debug/understand the rules: - for iptables, each portmapping is a DNAT rule with a comment pointing at the 'service',i.e: -A PREROUTING ! -i tailscale0 -p tcp -m tcp --dport 4006 -m comment --comment "some-svc:tcp:4006 -> tcp:80" -j DNAT --to-destination 100.64.1.18:80 Additionally there is a SNAT rule for each tailnet target, to mask the source address. - for nftables, a separate prerouting chain is created for each tailnet target and all the portmapping rules are placed in that chain. This makes it easier to look up rules and delete services when no longer needed. (nftables allows hooking a custom chain to a prerouting hook, so no extra work is needed to ensure that the rules in the service chains are evaluated). The next steps will be to get the Kubernetes Operator to generate the configfile and ensure it is mounted to the relevant proxy nodes. Updates tailscale/tailscale#13406 Signed-off-by: Irbe Krumina <irbe@tailscale.com>	2 years ago