Gateways of a GatewayClass whose controllerName is reweave.levk.dev/gateway
are served like LoadBalancer Services: a Gateway names one IPv4 address in
spec.addresses, and the node holding that address serves all of it and
writes its status.
- TCP listeners forward the oldest TCPRoute attached to them in the kernel,
through the same DNAT and reply steering as LoadBalancer Services, so the
backend sees the client's own address.
- HTTP and HTTPS listeners are served by the agent itself on the holder:
TLS terminated with the listener's certificate (chosen by SNI, swapped in
place when its Secret changes, HTTP/2 offered), requests routed by the
attached HTTPRoutes in the order the spec prescribes (hostname, exact
path, longest prefix, method, headers, query, age, name, rule), and passed
to a ready endpoint of the backend with X-Forwarded-For built from this
hop only. RequestRedirect, URLRewrite and both header modifiers are
implemented; other filters and regular expressions are refused
(Accepted False, UnsupportedValue). Bodies are streamed, never limited.
Unresolved backends answer 500, backends without ready endpoints 503,
requests nothing matches 404. Those ports are let in ahead of the host
firewall (REWEAVE-LB-IN).
Listeners are checked for protocol, route kinds, certificates (Secrets in
the Gateway's namespace or granted by a ReferenceGrant, and only in the
namespaces the agent may read: --gateway-namespaces, default
gateway-system), conflicts on a port, and ports LoadBalancer Services
already forward. Routes attach by parentRef (sectionName, port),
allowedRoutes (namespaces Same, All or Selector; kinds) and hostname
intersection, with the spec's conditions and reasons.
One writer per status: the holder writes its Gateway's (the first node by
name when nobody holds the address, so failures are reported once), the
first node by name writes GatewayClass and route statuses, keeping other
controllers' route parents. Writes are conditional on the resourceVersion
they were computed from, and a condition keeps its transition time while
its status stands, so an unchanged status is never rewritten.
The types are plain structs for the subset implemented (the upstream module
needs a newer client-go than the fork's); the CRDs are installed apart from
this manifest, which grants the agent read access to the Gateway API kinds,
patch on their status, and Secrets in gateway-system only.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UHXzGrsxfkGk8LmwrBbHNZ
With no EgressService and no member rules installed, an admission has
nothing to protect or clean up, so a failing pass (a datapath bug, a
bridge not yet addressed) answers "not a member" instead of stopping
every pod on the node from starting. Wherever EgressServices exist,
admission still fails closed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UHXzGrsxfkGk8LmwrBbHNZ
EgressService (reweave.levk.dev/v1alpha1, named after a LoadBalancer
Service of class reweave.levk.dev/node-address) makes every pod the
Service selects (by pod IP, never readiness) leave the cluster from the
Service's address, or not at all. spec.emit is explicit: Holder (the only
mode so far) tunnels members' packets to the node holding the address,
which emits them.
The holder (S1's: the one node with the address on an interface) is the
status' sole writer: host, address, and a 512-port block per node in
61000-65535 (above the default ephemeral range), stable across churn.
A member's node SNATs it to address:its-block before it leaves, so the
holder forwards it unchanged and routes replies back by port alone: ip
rules (to address, ipproto tcp/udp, dport block) ahead of the local
table, which moves from 0 to 100, since the address is local on the
holder. Members' packets travel both ways in reweave-eg, an ipip tunnel
between weave bridges (NPC drops new routed packets into weave), with
accept_local and loose rp_filter on that device only.
Members' new connections are classed at the tail of nat PREROUTING,
after kube-proxy's DNAT has ended the nat walk for Services: the pod
network, multicast and the nodes' addresses are not outside. Marked
packets follow a per-member rule to the holder's table (or to an
unreachable one), are SNATed into the tunnel, and a FORWARD guard drops
anything else a member sends outside (other protocols, other ways out).
The tunnel is accepted only from the nodes' bridges, a holder accepts
from it only the blocks' ports, and TCP MSS is clamped into it.
Fail closed throughout: until the holder has published the status,
without a block, with no single holder, or for a pod two EgressServices
select, a member's outside traffic is dropped. The CNI plugin asks
weave-npc to admit every pod (unix socket /run/weave-npc/egress.sock,
conflist "egressAdmission": true, now rewritten when it differs) after
IPAM and before the pod has an interface, so a member's first packet
already leaves from the address; no answer, no pod. weave-npc applies
nothing about egress from caches that are not synced (unless the API is
absent): a restart never strips members' rules.
reweave/test/egress/run.sh checks the design's assertions against a
live cluster; both end-to-end scripts now re-evaluate each check on
every retry (it was expanded once, before the loop).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UHXzGrsxfkGk8LmwrBbHNZ
A Service of type LoadBalancer with loadBalancerClass
reweave.levk.dev/node-address names its address in spec.loadBalancerIP.
Each node's weave-npc publishes the IPv4 addresses on its host interfaces
and its weave bridge (Node annotations reweave.levk.dev/addresses and
reweave.levk.dev/weave). The one node that holds a Service's address is
its holder: it alone writes status.loadBalancer (ipMode Proxy, so
kube-proxy installs nothing for the address) and DNATs the address's ports
to ready endpoints (EndpointSlices), without SNAT, from nat PREROUTING
ahead of kube-proxy. Every other node marks the connections the holder
forwards to its pods (new, from the holder's bridge MAC, from outside the
pod network) and routes their replies back to the holder's bridge through
a per-holder policy rule and table, so the holder's conntrack undoes the
DNAT and the reply leaves from the address the client connected to.
Fail closed: an address no node holds, or that several nodes hold, is
served by no node, and its status is cleared (by its holder, or by the
first node by name if none holds it). Compute is the policy as a pure
function; Datapath replaces exactly the chains it owns with
iptables-restore --noflush and keeps its rules and tables exact.
weave-npc runs it unless --lb=false; the ClusterRole gains services
(watch), services/status (patch), endpointslices (watch), nodes (patch).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UHXzGrsxfkGk8LmwrBbHNZ
levaliciousandClaude Opus 5.5