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
* Module name changed to `github.com/rajch/weave`
* Added environment variable `CHECKPOINT_DISABLE=1` to default manifests, to bypass weaveworks telemetry
This allows the main container to run without write access to the host
filesystem, except for two specific areas, thus trimming the attack
surface.
We lose the behaviour that the CNI plugin is only installed if Weave Net
gets up and running at least once, so the error reports from kubelet
will be slightly different in the case that it never manages to run.
- Instead of EnsureBridge
- Adds ipset.ExistEntry method
- Refactor ipset method names Exist <-> EntryExists
- Turn on iptable-refresh by default (10s)
- Adds a test that checks iptables are refreshed, check EXPOSE recovers
Only block the specific port Weave Net is listening on.
Add a comment so users know what the rule is for.
Remove the rule added in v2.6.3 because it was too coarse.
levaliciousandClaude Opus 5.5