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>
cmd/k8s-operator: add logic to parse L7 Ingresses in HA mode
- Wrap the Tailscale API client used by the Kubernetes Operator
into a client that knows how to manage VIPServices.
- Create/Delete VIPServices and update serve config for L7 Ingresses
for ProxyGroup.
- Ensure that ingress ProxyGroup proxies mount serve config from a shared ConfigMap.
Updates tailscale/corp#24795
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
cmd/containerboot,kube/kubetypes,cmd/k8s-operator: detect if Ingress is created in a tailnet that has no HTTPS
This attempts to make Kubernetes Operator L7 Ingress setup failures more explicit:
- the Ingress resource now only advertises HTTPS endpoint via status.ingress.loadBalancer.hostname when/if the proxy has succesfully loaded serve config
- the proxy attempts to catch cases where HTTPS is disabled for the tailnet and logs a warning
Updates tailscale/tailscale#12079
Updates tailscale/tailscale#10407
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
