#14: Spaceship PUT keys records by name+type+VALUE, so changing an
existing RRSet's value APPENDS a second record (a double v=spf1 =
RFC 7208 permerror). Correct pattern: PUT new, DELETE old; DELETE body
is a bare JSON array, not {items:[...]}.
#15: ed25519 DKIM "fail" at Gmail alongside passing RSA is the known
Stalwart dual-signing issue, not a key problem -- proved the stored
seed derives the published p= exactly. Fix is RSA-only: removed the
ed25519 DNS key (done); disabling the ed25519 signature in Stalwart is
the remaining step. Also records the smarthost identity behind the SPF
fix. Corrected #13's "PUT won't disturb siblings" claim accordingly.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Add enable_ipv6 + a ULA subnet to tailwart_default so the Stalwart
container (sharing the ts-stalwart netns) gets working IPv6 egress.
Because only egress is needed (inbound arrives via the edge/tailnet),
a ULA + Docker masquerade suffices -- no routable prefix, ndppd, or
host sysctl changes (Docker 29 enables ip6tables by default; host
forwarding was already on). Verified: ping6 + TCP/443 to v6 literals
from inside the netns; zero ENETUNREACH since boot.
LESSONS: mark #8/#9 resolved with the ULA-masquerade recipe, and add
#13 -- Spaceship's DNS API is RRSet-upsert (not zone-replace), so
Stalwart/ACME did not eat custom AAAA records; a vanished AAAA is a
provider-side loss, not Stalwart. Includes the safe read/verify flow
and the "don't publish mail AAAA before edge v6 listeners" caveat.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
LESSONS.md gains 8-12: container has no IPv6 (AAAA fails before A, no
fallback), host IPv6 != container IPv6, VPS blocks all outbound SMTP
ports (relay over tailnet), sidecar needs a source ACL grant to
initiate, and MtaRoute changes only take effect on restart.
CLAUDE.md and .env.example warn that the smarthost address must be an
IPv4 literal or tailnet IP, never a dual-stack hostname. acl-snippet
adds the tag:stalwart -> tag:mail outbound grant.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Fixes the root cause that was silently dropping Stalwart's cert/setting
writes, completes the public HTTPS endpoints, and captures the debugging
knowledge.
- docker-compose.yml: gate the ts-stalwart healthcheck on Postgres
reachability (nc -z the-record-prod:5432) in addition to tailscaled
health. Stalwart's depends_on: service_healthy can no longer release it
into the window where the tailnet route to Postgres isn't up yet — which
was failing table init and losing in-flight cert writes (-> rcgen).
- caddy/caddy.json + README: add the :443 SNI fan-out. mta-sts /
autoconfig / autodiscover pass through to stalwart:443 (Stalwart
terminates TLS with its wildcard cert; no proxy_protocol on :443).
All other SNIs go to the box's web Caddy on :8443 (https_port 8443).
L7 reverse_proxy is impossible here: CAA pins issuance to Stalwart's
ACME account, so Caddy can't obtain its own cert for these names.
- acl-snippet.hujson: grant tcp:443 on reverse-proxy -> stalwart for the
SNI pass-through.
- config/config.json: track the v0.16 bootstrap (commit-safe; the DB
secret is an EnvironmentVariable reference, not inline).
- LESSONS.md: symptom -> cause -> fix notes (PG race, DNS-01/Spaceship
dead key, auto-ban vs PROXY protocol, wildcard-requires-DNS-01, SNI
pass-through, ephemeral sidecar IP, LE rate-limit checks).
- .gitignore: exclude _backup/ and _validate/ (DB dumps + an inline-secret
config) and editor swap files. NEVER commit those.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
