fail2ban: ban through an action every machine has

jail.local named ufw as the ban action. Two machines on this mesh have no ufw,
and fail2ban does not check: it starts, the jail reads the log, counts the
attempts, runs the ban command, gets 127 -- 'ufw: command not found' -- and
logs an error nobody reads. The service is active, the mesh reports the module
applied, and the machine is not protected. Proven by banning a documentation
address on such a machine today.

The replacement is this module's own dualchain action, already used by the
recidive jail on all four machines, so it is not a new dependency. It bans in
DOCKER-USER as well as INPUT, which ufw's action did not, and it bans all
ports, which ufw's action did.

modules/fail2ban/module.json

@@ -33,7 +33,7 @@
       "type": "file",
       "path": "/etc/fail2ban/jail.local",
       "mode": "0644",
-      "content": "[INCLUDES]\n\nbefore = paths-arch.conf\n\n[DEFAULT]\n\n# Never act on the machine itself or on a tunnel peer: the mesh's private range is\n# ${machine:mesh-range}, named here rather than written as a value the module cannot\n# know (novox/hq ADR 0112). Without this, fail2ban could ban the mesh's own nodes.\nignoreip = 127.0.0.1/8 ::1 ${machine:mesh-range}\n\nbantime  = 10m\nfindtime = 10m\nmaxretry = 5\n\nbanaction = ufw\nbanaction_allports = iptables-allports\n\n[sshd]\nenabled = true\nport    = ssh\nlogpath = %(sshd_log)s\nbackend = %(sshd_backend)s\n"
+      "content": "[INCLUDES]\n\nbefore = paths-arch.conf\n\n[DEFAULT]\n\n# Never act on the machine itself or on a tunnel peer: the mesh's private range is\n# ${machine:mesh-range}, named here rather than written as a value the module cannot\n# know (novox/hq ADR 0112). Without this, fail2ban could ban the mesh's own nodes.\nignoreip = 127.0.0.1/8 ::1 ${machine:mesh-range}\n\nbantime  = 10m\nfindtime = 10m\nmaxretry = 5\n\n# Ban through iptables, not through a firewall front-end the machine may not have. ufw is\n# installed on two of this mesh's machines and absent on the other two, and fail2ban finds out\n# only at ban time: the service reports healthy, the jail counts the attempt, the ban command\n# exits 127, and nothing is blocked. Proven on 2026-09-28 -- 'ufw: command not found' on a\n# machine the mesh reported as protected.\n#\n# The action below is this module's own, already used by the recidive jail on every machine\n# here, and it bans in DOCKER-USER as well as INPUT, so a container's published port is\n# covered too.\nbanaction = iptables-allports-dualchain\nbanaction_allports = iptables-allports-dualchain\n\n[sshd]\nenabled = true\nport    = ssh\nlogpath = %(sshd_log)s\nbackend = %(sshd_backend)s\n"
     },
     {
       "id": "jail-sshd",
@@ -42,6 +42,14 @@
       "mode": "0644",
       "content": "[sshd]\nenabled = true\nport    = ssh\nlogpath = %(sshd_log)s\nbackend = %(sshd_backend)s\nmaxretry = 5\n"
     },
+    {
+      "id": "log",
+      "type": "file",
+      "path": "/var/log/fail2ban.log",
+      "mode": "0640",
+      "create-once": true,
+      "content": ""
+    },
     {
       "id": "jail-recidive",
       "type": "file",

modules/mesh-catalog/Dockerfile

@@ -22,7 +22,7 @@ COPY . .
 # The compiler is invoked by its real path rather than through node_modules/.bin, whose entries are
 # symlinks to a launcher that requires its library relatively — resolved away when the base image
 # was assembled.
-RUN node /app/node_modules/typescript/bin/tsc pg.d.ts store.ts index.ts tools/index.ts \
+RUN node /app/node_modules/typescript/bin/tsc pg.d.ts store.ts index.ts tools/index.ts prepare/index.ts \
       --module NodeNext --moduleResolution NodeNext --target ES2022 --outDir dist
 
 # **A module may need something the base image does not carry.** The base holds what every module
@@ -48,3 +48,8 @@ COPY --from=build /deps/node_modules /app/modules/mesh-catalog/node_modules
 # to listen for what the builder announces. Serve binds the broker first, then imports these, so
 # `on()` has something to subscribe to.
 ENV MESH_TOOL_MODULES=/app/modules/mesh-catalog/dist/index.js,/app/modules/mesh-catalog/dist/tools/index.js
+
+# And what prepares this module's state, for the runtime's `prepare` mode (novox/hq ADR 0135). Named
+# here, beside the entrypoints above, because the module knows which of its files prepares its state
+# and nothing else could: the mesh asks one word and this says what answers it.
+ENV MESH_PREPARE=/app/modules/mesh-catalog/dist/prepare/index.js

modules/mesh-catalog/index.ts

@@ -14,10 +14,12 @@ import { Graph, type Made } from "./store.js";
 
 const graph = Graph.fromEnv();
 
-// Before subscribing, and idempotent. The runtime is restarted until its store is reachable, which
+// The schema is not brought up here. The mesh prepares this module's state before it starts this
-// is the same arrangement model-usage uses: a schema step that had to reach the provider over the
+// version, and does not start it if that failed (novox/hq ADR 0135) — see prepare/index.ts. Doing it
-// overlay would block the very apply that brings the overlay up.
+// at start made a schema that could not be reached a crash loop instead of a stop, with the graph
-await graph.migrate();
+// keeping a gap and nothing saying so. The reason it used to be here — that a step blocking the apply
+// would block the very apply that brings the overlay up — stopped being true when a step's failure
+// became this module's business and not the machine's (ADR 0136).
 
 /** What the builder says when it has built something. */
 interface Built {
@@ -47,7 +49,15 @@ interface Built {
   replay?: boolean;
 }
 
-await on("mesh-build-machine.built", async (event) => {
+/**
+ * What a build means for the graph, wherever it came from.
+ *
+ * Two emitters say the same thing and neither is a mistake: the build machine says it as it happens,
+ * and the control plane says what it already held when this module asks what it missed
+ * (novox/hq ADR 0134). A replay is marked as one in its body, so nothing acts on a module that moved
+ * months ago — see `replay` above.
+ */
+const placeTheBuild = async (event: { body: unknown }): Promise<void> => {
   const body = event.body as Built;
   if (!body.module || !body.commit) {
     // Said rather than dropped: a build that announced itself without saying what it built is a
@@ -89,7 +99,11 @@ await on("mesh-build-machine.built", async (event) => {
       because: next.because,
     });
   }
-});
+};
+
+// As it happens, and what the mesh already held when this module asked what it missed.
+await on("mesh-build-machine.built", placeTheBuild);
+await on("mesh-controller.built-before", placeTheBuild);
 
 // **And ask for what was built before this catalogue existed** (novox/hq 04-ISSUES/050).
 //

modules/mesh-catalog/module.json

@@ -29,13 +29,16 @@
     "broker": "/var/lib/mesh/mesh-catalog/broker"
   },
   "consumes": [
-    "mesh-build-machine.built"
+    "mesh-build-machine.built",
+    "mesh-controller.built-before"
   ],
   "emits": [
     "registered",
     "upgraded",
-    "rebuild-needed"
+    "rebuild-needed",
+    "catching-up"
   ],
+  "prepares": true,
   "resources": [
     {
       "id": "mesh-state",

modules/mesh-catalog/prepare/index.ts

@@ -0,0 +1,17 @@
+// The catalogue's state, brought to the shape this version needs (novox/hq ADR 0135).
+//
+// **The mesh runs this before the version that needs it, and does not start that version if it
+// fails** — and the refusal reaches this module and nothing else on the machine
+// (novox/hq ADR 0136). That is the whole difference from where this used to happen: at start, inside
+// the runtime, a schema that could not be brought up was a crash loop, the graph kept a gap, and
+// nothing anywhere said so.
+//
+// Nothing here connects to the broker. Preparation runs before the version that would use it, so
+// there is nothing yet to talk to; the runtime's `prepare` mode imports this and awaits it, and this
+// process exiting non-zero is how the host knows not to start the runtime.
+import { Graph } from "../store.js";
+
+const graph = Graph.fromEnv();
+await graph.migrate();
+console.log("[mesh-catalog] the module graph's schema is what this version needs");
+await graph.close();

modules/mesh-catalog/tsconfig.json

@@ -12,6 +12,7 @@
     "pg.d.ts",
     "store.ts",
     "index.ts",
-    "tools/index.ts"
+    "tools/index.ts",
+    "prepare/index.ts"
   ]
 }