release: 2.6.0: audit stage 5 - image and Postfix hardening

Cut without asking, as the owner said on 2026-10-15.

The supervisord socket is root:supervisor, the panel the group's one member
(M17). Postfix takes TLS 1.2 at least, the client too where TLS is
required; VRFY off; the banner without the distribution; the start refuses
a rate, size or milter timeout that is not a number, under its minimum or
past an int (L31). OpenDKIM logs through the syslog relay to the container
log and oversigns From: (L30). crashexit takes the container down after
five unexpected exits of a mail-path program in ten minutes (L32).
logrotate keeps its state under /data/log. extract-cert.sh refuses what is
not PEM and renames whole files (M21). Plus the findings of both reviews
(a39eda5). Commits dab7715, a39eda5, b09e525.

Rolled out to the test server as 2.5.4-post.95af363 (the same code): the
container healthy, every program RUNNING, syslog-relay among them;
OpenDKIM's start line in docker logs under "syslog: "; the postconf values
as set; /run/supervisor.sock root:supervisor 0770 and the panel reaches it;
/data/log/.logrotate.status written. No migration, schema 11.

CHANGELOG cut; pin 2.6.0 in deploy/docker-compose.yml, README, guide (and
its sample restore message); development.md "from pin" and the stage's row;
roadmap row and recommended order; stage 5 marked shipped in the plan. No
tag.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -5,6 +5,17 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); version
 
 ## [Unreleased]
 
+## [2.6.0] - 2026-10-15
+
+Stage 5 of the 2026-10-12 audit: the image and Postfix. The supervisor
+socket is the panel's alone; Postfix takes TLS 1.2 at least, and the start
+refuses settings that would kill its daemons at the first connection;
+OpenDKIM's log reaches the container log and it oversigns From:; a program
+that keeps crashing takes the container down; logrotate remembers what it
+rotated; extract-cert.sh never replaces a certificate with nothing. A new
+program, `syslog-relay`, and a new group, `supervisor`, in the image; no
+migration.
+
 ### Security
 
 - **Postfix and OpenDKIM could stop every program in the container.** The

README.md

@@ -112,8 +112,8 @@ outbound mail will not reach the real internet without DNS, PTR, and port 25.
 > local image and pulls nothing:
 >
 > ```sh
-> docker build -f build/Dockerfile --build-arg VERSION=2.5.4 \
+> docker build -f build/Dockerfile --build-arg VERSION=2.6.0 \
->   -t ghcr.io/mixeme/selfpost:2.5.4 .
+>   -t ghcr.io/mixeme/selfpost:2.6.0 .
 > ```
 
 ```sh
@@ -122,7 +122,7 @@ docker run --rm -d --name selfpost-try \
   -e SELFPOST_HOSTNAME=mail.local.test \
   -e PANEL_COOKIE_SECURE=false \
   -v selfpost-try-data:/data \
-  ghcr.io/mixeme/selfpost:2.5.4
+  ghcr.io/mixeme/selfpost:2.6.0
 ```
 
 **Get the setup URL** (pick one):

deploy/docker-compose.yml

@@ -23,7 +23,7 @@
 
 services:
   selfpost:
-    image: ghcr.io/mixeme/selfpost:2.5.4
+    image: ghcr.io/mixeme/selfpost:2.6.0
     restart: unless-stopped
     environment:
       SELFPOST_HOSTNAME: "${SELFPOST_HOSTNAME:?set the mail/panel hostname, e.g. mail.example.com}"

docs/audit-2026-10-12.md

@@ -1416,7 +1416,7 @@ failed `SetNotifyAddressees` is logged and the subject stays said, the next
 follow-up finds nobody owed; the profile form's "username taken" is
 documented in security.md.
 
-### Stage 5 — image and Postfix hardening (M17–M19, M21, L30–L32) → `2.6.0`
+### Stage 5 — image and Postfix hardening (M17–M19, M21, L30–L32) → `2.6.0` (shipped 2026-10-15)
 
 - [x] **Supervisor socket**: a group of its own (`supervisor`), panel only;
    `postfix`/`opendkim` keep `selfpost` for the file paths. — **Opus**

docs/development.md

@@ -107,7 +107,7 @@ than the default «meaningful step» rule in [§ Commits and release build](#com
 2. Git tag `vX.Y.Z` and publish the GitHub Release only on explicit request (see
    [§ Release image](#release-image)).
 
-**Planned version cuts** (from pin `2.5.4`; adjust if semver changes mid-track):
+**Planned version cuts** (from pin `2.6.0`; adjust if semver changes mid-track):
 
 | Stage | ID | Cut |
 |---|---|---|
@@ -136,7 +136,7 @@ than the default «meaningful step» rule in [§ Commits and release build](#com
 | 23 | audit-2026-10-12 stage 2c: the sender check reads From: as OpenDKIM does | `2.5.2` |
 | 24 | audit-2026-10-12 stage 3: persistence and restore | `2.5.3` |
 | 25 | audit-2026-10-12 stage 4: panel behaviour | `2.5.4` |
-| 26 | audit-2026-10-12 stage 5 | `2.6.0` |
+| 26 | audit-2026-10-12 stage 5: image and Postfix hardening | `2.6.0` |
 
 Docs-only prep (checklists in plans, no product code) uses the same per-step
 commit rule but **no** version cut until the next product stage ships.

docs/guide.md

@@ -190,14 +190,14 @@ cat ./data/setup-token
 #### Fixed image tag
 
 `deploy/docker-compose.yml` pins an explicit version (`ghcr.io/mixeme/selfpost:X.Y.Z`),
-deliberately never `:latest`. The current pin is `2.5.4`. **No 2.x image is
+deliberately never `:latest`. The current pin is `2.6.0`. **No 2.x image is
 published on ghcr.io yet** (the newest there is `1.3.0`); until one is, build
 it from the checkout under the pinned name, and Compose uses the local image
 instead of pulling:
 
 ```sh
-docker build -f build/Dockerfile --build-arg VERSION=2.5.4 \
+docker build -f build/Dockerfile --build-arg VERSION=2.6.0 \
-  -t ghcr.io/mixeme/selfpost:2.5.4 .
+  -t ghcr.io/mixeme/selfpost:2.6.0 .
 ```
 
 `VERSION` must equal the tag: it is the version the backup check compares
@@ -861,7 +861,7 @@ A version mismatch at step 5 refuses to start and leaves `/data` untouched —
 the panel exits with a message naming the tag to use, e.g.:
 
 ```
-backup: this backup was created by SelfPost 2.5.3 but this image is 2.5.4 — restore into the matching image (selfpost:2.5.3)
+backup: this backup was created by SelfPost 2.5.4 but this image is 2.6.0 — restore into the matching image (selfpost:2.5.4)
 ```
 
 Fix the tag in `docker-compose.yml` (build that tag as under [Fixed image

docs/roadmap.md

@@ -46,7 +46,7 @@ in `git log` and [CHANGELOG.md](../CHANGELOG.md).
 | from-header-binding | Hold a message's `From:` header against the application that sends it | shipped `2.4.0` | 9/9 | [plans/from-header-binding.md](plans/from-header-binding.md) |
 | panel-redesign | Panel redesign (accepted mockups, design contract) | shipped `2.0.0` | 27/27 | [plans/panel-redesign.md](plans/panel-redesign.md) |
 | schema-squash | Squash SQLite migrations into a 2.x baseline | built in panel-redesign (stage 1) | — | [plans/panel-redesign.md](plans/panel-redesign.md) |
-| audit-2026-10-12 | Follow-ups of the 2026-10-12 full-tree code audit, seven stages | in progress (stage 0 shipped `2.4.2`, stages 1+2 `2.5.0`, 2b `2.5.1`, 2c `2.5.2`, 3 `2.5.3`, 4 `2.5.4`; next stage 5 → `2.6.0`) | 77/81 | [audit-2026-10-12.md](audit-2026-10-12.md) |
+| audit-2026-10-12 | Follow-ups of the 2026-10-12 full-tree code audit, seven stages | in progress (stage 0 shipped `2.4.2`, stages 1+2 `2.5.0`, 2b `2.5.1`, 2c `2.5.2`, 3 `2.5.3`, 4 `2.5.4`, 5 `2.6.0`; next stage 6, docs only) | 77/81 | [audit-2026-10-12.md](audit-2026-10-12.md) |
 
 **Recommended order** (not binding; owner, 2026-10-09: feature order follows
 development convenience): **panel-redesign** shipped as `2.0.0` (2026-10-11) and
@@ -56,8 +56,8 @@ shipped as `2.2.0` the same day, **panel-notifications** as `2.3.0` and
 **from-header-binding** as `2.4.0`. Stage 0 of
 [audit-2026-10-12](audit-2026-10-12.md) shipped as `2.4.2` (2026-10-14), its
 stages 1 and 2 as `2.5.0` the same day, stage 2b as `2.5.1`, stage 2c as
-`2.5.2` (2026-10-15), and stages 3 and 4 as `2.5.3` and `2.5.4` the same
+`2.5.2` (2026-10-15), and stages 3, 4 and 5 as `2.5.3`, `2.5.4` and
-day.
+`2.6.0` the same day.
 Nothing is agreed after it: every remaining
 item is a candidate. panel-docs shipped in
 [CHANGELOG.md](../CHANGELOG.md) `[1.8.0]`; dmarc-reports in `[1.7.0]`