fix(crowdsec): stop the 403 loop that banned our own VPS and runner
Chasing why apply-k8s kept dying mid-run turned up a self-inflicted
ban loop. 585 of 586 LePresidente/http-generic-403-bf alerts in the LAPI
came from 193.181.211.79 - our own VPS - POSTing
/management.ManagementService/GetServerKey, i.e. the NetBird client's
own management call. netbird-server had never seen a single one of them,
so the 403 was not NetBird's: the bouncer was rejecting the request
before it got there. A banned peer keeps retrying, each retry is another
403, and the scenario turns five 403s in ten seconds into a 4h ban, so
the loop kept re-arming the ban it was serving. The hourly janitor step
that deleted those decisions hourly was masking all of it.
* netbird/k8s/ingress.yaml - drop the bouncer from the mesh API routes
(gRPC-gateway management, signal, relay, /api, /oauth2). A ban there
locks a peer out of the network it needs to reach anything else, and
those endpoints authenticate by NetBird token, not by a login form.
The dashboard keeps the bouncer; it is a real login surface.
netbird-local was already exempt, so this makes prod match.
* crowdsec-middleware.yaml - CrowdsecMode stream instead of live. live
blocked on GET /v1/decisions per request, so a burst saturated the
LAPI and the plugin 403'd IPs that were never banned. v1.3.3 ignores
UpdateMaxFailure in live, so fail-open is only reachable in stream;
-1 now means an unreachable LAPI degrades to "no protection" rather
than "every site 403". 15s poll instead of the 60s default, because
the runner shares one public IP with the house.
Also corrects the key name: HTTPTimeoutSeconds, not
CrowdsecLapiTimeout, which never existed and was being silently
dropped, leaving the 10s default. Back at 10, not the 2s f7cd75d
guessed - a pull that times out leaves the ban cache frozen at its
startup contents, so new bans would silently never apply.
* crowdsec-values.yaml - CIDR allowlisting moves to parsers/s02-enrich,
where CrowdSec's docs put it: a parser whitelist drops the event before
it reaches a bucket, so those addresses never become a decision at
all. The old postoverflow LAN list was checked only after the ban
existed, which is the window the deploy kept landing in. Added
100.64.0.0/10, which the RFC 1918 blocks miss and where the
workstation, the k0s node and the VPS actually live. The DDNS
home-IP whitelist stays in postoverflows, because resolving a hostname
is the expensive check the docs reserve that stage for.
ClientTrustedIPs mirrors that list so the bouncer skips the LAPI
round-trip entirely for those addresses.
* janitor-cronjob.yaml - drop step 5. The bouncer can no longer
manufacture 403s, so the only remaining firings of that scenario are
real scanners, and deleting their decisions hourly was undoing a
working ban.
* Also lands the LAPI config.yaml.local (SQLite WAL, Central API off,
bounded flush) that f7cd75d's comments referenced but never included:
the LAPI was blocked in fsync on its rollback journal, and the CAPI
resolver held a write transaction while timing out against a host
this network cannot reach.
Verified in-cluster: no new 403-bf alerts in the 3.5min after applying,
the management endpoint answers 404 from the backend instead of 403 from
the bouncer in 0.17s, and the VPS client reports Management and Signal
connected with 2/2 relays.
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@@ -58,26 +58,15 @@ config:
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reason: "Mobile IP whitelist"
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cidr:
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- "84.245.64.0/18"
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postoverflows:
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s01-whitelist:
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home-dynamic-ip.yaml: |
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name: forust/home-dynamic-ip
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description: "Whitelist home dynamic IP"
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whitelist:
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reason: "Home dynamic IP"
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expression:
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- evt.Overflow.Alert.Source.IP in LookupHost("ddns.forust.xyz")
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# The hairpin-NAT address of the router (192.168.88.1) is what the
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# Gitea Actions runner presents to Traefik - it is NOT the home
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# dynamic IP, so the whitelist above did not cover it. During a
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# deploy the runner POSTs to the Actions API many times a second;
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# a single 403 storm was enough to earn it a 4h ban and break every
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# later job. Whitelisting the whole LAN also covers phones and
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# tablets browsing over 192.168.88.0/24.
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lan.yaml: |
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name: forust/lan
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description: "Whitelist local network"
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# CrowdSec's own guidance: CIDR allowlisting belongs at the parser stage.
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# A parser whitelist discards the event before it reaches a bucket, so
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# these addresses never produce an overflow and never become a decision.
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# A postoverflow whitelist is checked only *after* the ban exists, and
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# the bouncer answers 403 for as long as it does - which is a window we
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# do not want the deploy sitting in.
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local-network.yaml: |
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name: forust/local-network
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description: "Whitelist loopback, private and VPN networks"
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whitelist:
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reason: "Local network"
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cidr:
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@@ -85,6 +74,81 @@ config:
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- "10.0.0.0/8"
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- "172.16.0.0/12"
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- "192.168.0.0/16"
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# CGNAT range (RFC 6598). The workstation and the k0s node live
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# here on WireGuard, and 100.64.0.0/10 is not covered by the
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# RFC 1918 blocks above.
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- "100.64.0.0/10"
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- "169.254.0.0/16"
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- "fc00::/7"
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- "fe80::/10"
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postoverflows:
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s01-whitelist:
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# The one whitelist that has to stay here: resolving a hostname is a
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# network call, and the docs put expensive lookups in postoverflows on
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# purpose - it runs only when a bucket actually overflows.
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# ddns.forust.xyz is the public home address, not a private one, so
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# forust/local-network does not cover it.
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home-dynamic-ip.yaml: |
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name: forust/home-dynamic-ip
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description: "Whitelist home dynamic IP"
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whitelist:
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reason: "Home dynamic IP"
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expression:
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- evt.Overflow.Alert.Source.IP in LookupHost("ddns.forust.xyz")
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# LAPI-only main config override, merged over config.yaml. NOTE: the
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# chart's own default for this key is REPLACED, not merged, so its
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# auto_registration block is repeated verbatim below - drop it and the
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# agent can no longer register itself.
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config.yaml.local: |
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api:
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server:
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auto_registration: # Activate if not using TLS for authentication
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enabled: true
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token: "${REGISTRATION_TOKEN}" # /!\ Do not modify this variable (auto-generated and handled by the chart)
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allowed_ranges: # /!\ Make sure to adapt to the pod IP ranges used by your cluster
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- "127.0.0.1/32"
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- "192.168.0.0/16"
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- "10.0.0.0/8"
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- "172.16.0.0/12"
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# This homelab has no egress to console.crowdsec.cloud: DNS does
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# not resolve. The LAPI kept trying anyway ("Signal push: N
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# signals to push", "capi metrics: sending" every 10s) and each
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# attempt sat on a resolver timeout WHILE HOLDING A WRITE
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# TRANSACTION, which is what kept stalling per-request decision
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# lookups even with WAL enabled. Nothing to share and nothing to
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# pull - turn the Central API off instead of letting it block the
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# only database writer we have.
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online_client:
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sharing: false
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pull:
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community: false
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blocklists: false
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disable_usage_metrics_export: true
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db_config:
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# SQLite without WAL serialises every reader behind the writer's
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# rollback journal, and the LAPI writes constantly: the agent pushes
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# Traefik alerts read from Loki, the metrics collector counts
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# decisions, the bouncer touches "last pull" on every request.
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# Symptom: decision lookups taking 10-30s (and a second connection
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# that could not even open the database) while the LAPI sat at 28m
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# CPU - the process was blocked in fsync, not computing. Every
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# bouncer-protected request then blew through the plugin timeout and
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# fail-closed with 403, on every site at once.
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# The PVC is local-path-retain (hostPath), not a network share, so
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# WAL is safe here; the crowdsec docs recommend it for exactly this
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# ("allowing more concurrency in SQLite that will improve
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# performances in most scenarios").
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use_wal: true
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# Keeps the alert table bounded. At the 5000/7d default the file
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# reached 54MB in 15 days off the Traefik access log alone, and the
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# metrics collector counts decisions on a timer; a smaller working
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# set means fewer full scans. Crowdsec only prunes - SQLite never
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# shrinks the file, so the size stays until a manual VACUUM.
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flush:
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max_items: 1000
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max_age: 24h
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lapi:
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env:
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