n8n: its own image built from source, placed data, and what its workflows use

The module named /var/lib/n8n, /services/n8n/n8n-data and n8n.novox.be -
paths and a domain no definition may carry (ADR 0112). State and data are
placed directories; the public name is ${bound:route:name} (depends on
mesh-controller #149), for N8N_HOST and WEBHOOK_URL alike.

The endpoint said 5682 while the container publishes 5678. 5682 was one
machine's host port; the endpoint is the software's port and the mesh
assigns the machine's (ADR 0038).

n8n had been run from an image in a registry that no longer exists: the
upstream image plus shadow, a `media` group (2000) with `node` in it, and
a global `uuid`. That recipe is now this module's Dockerfile, built on the
upstream 1.71.3 image named in build.on by digest, with uuid pinned to the
version the running image carries (14.0.1) - Code nodes require() it. The
media group is how the container writes into the shared media library, a
read-write `access` (ADR 0051), mounted where workflows expect it,
/media-library.

The workflows also use a redis (the Redis nodes of the chat workflows) and a
Selenium Chrome (the scraper), which the previous deployment ran beside n8n.
Both are containers on the module's own network, publishing nothing, pinned
to the digests in use; redis keeps its append-only file in a placed
directory.

The basic-auth secret is gone: N8N_BASIC_AUTH_* was removed in n8n 1.0 and
did nothing. The grant's password is a 0400 file owned by `node`, read
through DB_POSTGRESDB_PASSWORD_FILE, so nothing secret is in the
environment. The credentials' encryption key is n8n's own, in the data
directory (config), and moves with it - nothing to mint or accept.

Verified: catalogue tests with MESH_CATALOGUE set; the Dockerfile built
against the pinned base gives n8n 1.71.3, uid 1000 in group 2000, uuid
14.0.1 - the running image's shape. Throwaway containers: an instance on
PostgreSQL 15 with an owner, a workflow and an encrypted credential;
stopped, copied, dumped from the copy, restored (--no-owner --role, the
uuid-ossp extension pre-made by the superuser) into a grant-shaped
database on the postgres module's pgvector image (PG17); the new shape
(password from the file, data dir copied) serves /healthz, the owner logs
in, the workflow is listed, and the credential decrypts with the carried
key. The node user writes into a root:2000 0775 library through the media
group; redis and Selenium resolve by name on the module network and
Selenium reports ready. Test containers and data removed.

modules/ca-trust/module.json

@@ -0,0 +1,56 @@
+{
+  "module": "ca-trust",
+  "version": "1",
+  "slug": "catrust",
+  "capabilities": [
+    "service-manager"
+  ],
+  "requires": [
+    "internal-acme-ca"
+  ],
+  "seats": [
+    {
+      "name": "the-mesh-trust-anchor",
+      "scope": "node"
+    }
+  ],
+  "claims": [
+    {
+      "name": "the-mesh-trust-anchor",
+      "scope": "node"
+    }
+  ],
+  "resources": [
+    {
+      "id": "state",
+      "type": "directory",
+      "mode": "0700",
+      "place": "."
+    },
+    {
+      "id": "anchor",
+      "type": "file",
+      "path": "${dir:state}/anchor",
+      "mode": "0755",
+      "content": "#!/bin/sh\n# The mesh's internal certificate authority, trusted by this machine.\n#\n# Written by the mesh from the ca-trust module's manifest (novox/hq ADR 0147).\n# Editing it here lasts until the next apply.\n#\n# There is no prior trust to verify the fetch against \u2014 this is the thing that\n# establishes it \u2014 so it is made over the mesh's own private network, which is\n# what authenticates it (novox/hq ADR 0098, the same reasoning that lets the\n# route proxy fetch this root for itself). What comes back is checked here: a\n# body that is not a certificate is refused now, rather than believed and then\n# failed by whatever reads the trust store next.\nset -eu\n\nROOTS='https://${bound:internal-acme-ca:at}:${bound:internal-acme-ca:port}${bound:internal-acme-ca:roots}'\nANCHORS=/etc/ca-certificates/trust-source/anchors\nANCHOR=\"$ANCHORS/mesh-internal-ca.crt\"\n\n# Arch's layout, said out loud rather than assumed: a machine that keeps its\n# anchors elsewhere fails here, visibly, instead of writing a file nothing\n# reads. That failure is the signal that this belongs in the host, where one\n# operating system's difference lives (novox/hq ADR 0147, option 2).\n[ -d \"$ANCHORS\" ] || {\n\techo \"this machine keeps no trust anchors in $ANCHORS; ca-trust is written for that layout\" >&2\n\texit 1\n}\n\ncase \"${1:-}\" in\ninstall)\n\ttmp=$(mktemp)\n\ttrap 'rm -f \"$tmp\"' EXIT\n\t# The authority may still be starting, or this machine may have come up\n\t# before it: two minutes of asking, then an honest failure.\n\tn=0\n\twhile [ \"$n\" -lt 60 ]; do\n\t\tif curl --fail --silent --show-error --insecure --max-time 10 \\\n\t\t\t--output \"$tmp\" \"$ROOTS\" &&\n\t\t\tgrep -q 'BEGIN CERTIFICATE' \"$tmp\"; then\n\t\t\tinstall -m 0644 \"$tmp\" \"$ANCHOR\"\n\t\t\tupdate-ca-trust\n\t\t\texit 0\n\t\tfi\n\t\tn=$((n + 1))\n\t\tsleep 2\n\tdone\n\techo \"the authority at $ROOTS did not serve a certificate within two minutes\" >&2\n\texit 1\n\t;;\nremove)\n\t# What stopping the unit does, and therefore what being unassigned does.\n\trm -f \"$ANCHOR\"\n\tupdate-ca-trust\n\t;;\n*)\n\techo \"usage: $(basename \"$0\") install|remove\" >&2\n\texit 2\n\t;;\nesac\n"
+    },
+    {
+      "id": "unit",
+      "type": "file",
+      "path": "/etc/systemd/system/mesh-ca-trust.service",
+      "mode": "0644",
+      "content": "[Unit]\nDescription=The mesh's internal certificate authority, trusted by this machine\n# novox/hq ADR 0147. Starting this unit places the mesh's root among this\n# machine's trust anchors; stopping it takes the root away again, which is what\n# the host does when the module is no longer assigned here.\nWants=network-online.target\nAfter=network-online.target\n\n[Service]\nType=oneshot\nRemainAfterExit=yes\nExecStart=${dir:state}/anchor install\nExecStop=${dir:state}/anchor remove\n\n[Install]\nWantedBy=multi-user.target\n"
+    },
+    {
+      "id": "trust",
+      "type": "service",
+      "unit": "mesh-ca-trust.service",
+      "state": "running",
+      "boot": "enabled",
+      "restart-on": [
+        "anchor",
+        "unit"
+      ]
+    }
+  ]
+}

modules/n8n/Dockerfile

@@ -0,0 +1,20 @@
+# n8n with what its workflows reach for beyond the upstream image.
+#
+# The base is named, not pinned here (novox/hq issue 044): module.json's `build.on` declares N8N_BASE
+# as the upstream image by digest, and the mesh hands the build its own copy (ADR 0097).
+ARG N8N_BASE
+FROM ${N8N_BASE}
+
+USER root
+# - `media` (GID 2000), with `node` in it: the shared media library is group-writable by the
+#   operator's media group, and a workflow files downloads into it. A container resource cannot add
+#   a supplementary group, so the image's own /etc/group carries it. 2000 is the operator's media
+#   group today; novox/hq 153 proposes reading it from the accessed data (${access:<id>:gid}).
+# - uuid, pinned to the version the workflows were written against: Code nodes require() it
+#   (NODE_FUNCTION_ALLOW_EXTERNAL=*), and a Code node can only require what is installed.
+RUN apk add --no-cache shadow \
+ && groupadd -g 2000 media \
+ && usermod -aG media node \
+ && npm install -g uuid@14.0.1
+
+USER node

modules/n8n/module.json

@@ -18,44 +18,60 @@
     }
   },
   "binds": {
-    "postgres-database": "/var/lib/n8n/database.json",
-    "route": "/var/lib/n8n/route.json"
+    "postgres-database": "${dir:state}/database.json",
+    "route": "${dir:state}/route.json"
   },
   "secrets": {
-    "postgres-database": "/var/lib/n8n/database.secret"
-  },
-  "own-secrets": {
-    "basic-auth": "/var/lib/n8n/basic-auth.secret"
+    "postgres-database": "${dir:state}/database.secret"
   },
+  "accesses": [
+    {
+      "path": "/services/media",
+      "mode": "read-write"
+    }
+  ],
   "listens": [
     {
       "name": "web",
-      "port": 5682,
+      "port": 5678,
       "protocol": "tcp",
       "from": "mesh",
-      "why": "the n8n editor and webhook endpoints over http; the public name n8n.novox.be is a route grant, and route-proxy reaches it on this published port"
+      "why": "the n8n editor, its REST API and the webhook endpoints workflows are triggered through; a public name is the route's"
     }
   ],
   "resources": [
     {
       "id": "state",
       "type": "directory",
-      "path": "/var/lib/n8n",
-      "mode": "0700"
+      "mode": "0700",
+      "place": "."
     },
     {
       "id": "data",
       "type": "directory",
-      "path": "/services/n8n/n8n-data",
       "mode": "0700",
       "owner": "1000:1000"
     },
+    {
+      "id": "cache",
+      "type": "directory",
+      "mode": "0700",
+      "owner": "999:999"
+    },
+    {
+      "id": "database-secret",
+      "type": "file",
+      "path": "${dir:state}/n8n-database.secret",
+      "mode": "0400",
+      "owner": "1000:1000",
+      "content": "${secret:postgres-database}"
+    },
     {
       "id": "server-env",
       "type": "file",
-      "path": "/var/lib/n8n/server.env",
+      "path": "${dir:state}/server.env",
       "mode": "0600",
-      "content": "N8N_HOST=n8n.novox.be\nN8N_PORT=5678\nN8N_PROTOCOL=https\nWEBHOOK_URL=https://n8n.novox.be/\nN8N_BASIC_AUTH_ACTIVE=true\nN8N_BASIC_AUTH_USER=admin\nN8N_BASIC_AUTH_PASSWORD=${secret:basic-auth}\nNODE_FUNCTION_ALLOW_BUILTIN=*\nNODE_FUNCTION_ALLOW_EXTERNAL=*\nDB_TYPE=postgresdb\nDB_POSTGRESDB_HOST=${bound:postgres-database:at}\nDB_POSTGRESDB_PORT=${bound:postgres-database:port}\nDB_POSTGRESDB_DATABASE=${bound:postgres-database:as}\nDB_POSTGRESDB_USER=${bound:postgres-database:as}\nDB_POSTGRESDB_PASSWORD=${secret:postgres-database}\n"
+      "content": "N8N_HOST=${bound:route:name}\nN8N_PORT=5678\nN8N_PROTOCOL=https\nWEBHOOK_URL=https://${bound:route:name}/\nNODE_FUNCTION_ALLOW_BUILTIN=*\nNODE_FUNCTION_ALLOW_EXTERNAL=*\nDB_TYPE=postgresdb\nDB_POSTGRESDB_HOST=${bound:postgres-database:at}\nDB_POSTGRESDB_PORT=${bound:postgres-database:port}\nDB_POSTGRESDB_DATABASE=${bound:postgres-database:as}\nDB_POSTGRESDB_USER=${bound:postgres-database:as}\nDB_POSTGRESDB_PASSWORD_FILE=/run/secrets/database\n"
     },
     {
       "id": "net",
@@ -66,18 +82,61 @@
       "id": "server",
       "type": "container",
       "name": "n8n",
-      "image": "n8nio/n8n@sha256:4846eb2f4b874ab04cde7fc1e249d2ddaec66e9aea64439beb2972cfea88e3c0",
+      "artifact": "server",
       "network": "n8n",
       "env-file": [
-        "/var/lib/n8n/server.env"
+        "${dir:state}/server.env"
       ],
       "ports": [
         "5678"
       ],
       "volumes": [
-        "/services/n8n/n8n-data:/home/node/.n8n"
+        "${dir:data}:/home/node/.n8n",
+        "${dir:state}/n8n-database.secret:/run/secrets/database:ro",
+        "/services/media:/media-library"
+      ]
+    },
+    {
+      "id": "cache-server",
+      "type": "container",
+      "name": "n8n-redis",
+      "image": "redis@sha256:8a1efc5f479551822b47424ccae982026b633f28818eab0387348120a61e10e2",
+      "network": "n8n",
+      "args": [
+        "redis-server",
+        "--appendonly",
+        "yes"
       ],
-      "secrets-in-environment": "n8n's loader honours <VAR>_FILE for every setting; convertible, awaiting a bed that proves it (N8N_BASIC_AUTH_* was removed in n8n 1.0 and is likely dead)"
+      "volumes": [
+        "${dir:cache}:/data"
+      ]
+    },
+    {
+      "id": "browser",
+      "type": "container",
+      "name": "n8n-selenium",
+      "image": "selenium/standalone-chrome@sha256:9ae1c78e9b2ca9fe4b22e57873b5ee34aeb8e814e3122293eef4c3abe4c5f448",
+      "network": "n8n",
+      "env": {
+        "SE_ENABLE_TRACING": "false",
+        "SE_NODE_MAX_SESSIONS": "5",
+        "SE_NODE_OVERRIDE_MAX_SESSIONS": "true"
+      }
     }
-  ]
+  ],
+  "build": {
+    "on": [
+      {
+        "arg": "N8N_BASE",
+        "image": "n8nio/n8n@sha256:4846eb2f4b874ab04cde7fc1e249d2ddaec66e9aea64439beb2972cfea88e3c0"
+      }
+    ],
+    "artifacts": [
+      {
+        "name": "server",
+        "kind": "image",
+        "from": "Dockerfile"
+      }
+    ]
+  }
 }

modules/searxng/module.json

@@ -5,7 +5,7 @@
     "container-runtime"
   ],
   "own-secrets": {
-    "secret": "/var/lib/searxng-module/secret.secret",
+    "secret": "/var/lib/mesh/searxng/secret",
     "broker": "/var/lib/mesh/searxng/broker"
   },
   "listens": [
@@ -27,22 +27,14 @@
     {
       "id": "state",
       "type": "directory",
-      "path": "/var/lib/searxng-module",
-      "mode": "0700"
+      "mode": "0700",
+      "place": "."
     },
     {
       "id": "valkey-data",
       "type": "directory",
-      "path": "/var/lib/searxng-module/valkey-data",
       "mode": "0700"
     },
-    {
-      "id": "server-env",
-      "type": "file",
-      "path": "/var/lib/searxng-module/server.env",
-      "mode": "0600",
-      "content": "SEARXNG_SECRET=${secret:secret}\nSEARXNG_VALKEY_URL=valkey://valkey:6379/0\n"
-    },
     {
       "id": "net",
       "type": "network",
@@ -63,30 +55,39 @@
         "warning"
       ],
       "volumes": [
-        "/var/lib/searxng-module/valkey-data:/data"
+        "${dir:valkey-data}:/data"
       ]
     },
+    {
+      "id": "settings",
+      "type": "file",
+      "path": "${dir:state}/settings.yml",
+      "mode": "0600",
+      "merge": "json",
+      "content": "{\n  \"use_default_settings\": true,\n  \"server\": {\n    \"secret_key\": \"${secret:secret}\",\n    \"base_url\": false,\n    \"limiter\": false,\n    \"image_proxy\": false,\n    \"public_instance\": false\n  },\n  \"search\": {\n    \"formats\": [\"html\", \"json\"]\n  },\n  \"valkey\": {\n    \"url\": \"valkey://valkey:6379/0\"\n  }\n}\n"
+    },
     {
       "id": "server",
       "type": "container",
       "name": "searxng",
-      "image": "searxng/searxng@sha256:c7cc75852051bf6254afda6ed1b920dd1677d8efe4ab141bf558f02e582f4371",
+      "image": "searxng/searxng@sha256:cd8812607ab73730a0b1a0dc4990223fe1b9e383f6f35947114d0bef7f8bb441",
       "network": "searxng",
-      "env-file": [
-        "/var/lib/searxng-module/server.env"
-      ],
       "ports": [
         "8080"
       ],
-      "secrets-in-environment": "SEARXNG_SECRET is env-only, but settings.yml carries server.secret_key; convertible by mounting a generated settings.yml, not yet done"
+      "volumes": [
+        "${dir:state}/settings.yml:/etc/searxng/settings.yml:ro"
+      ],
+      "restart-on": [
+        "settings"
+      ]
     },
     {
       "id": "runtime-config",
       "type": "file",
       "path": "/var/lib/mesh/searxng/config.json",
       "mode": "0600",
-      "content": "{}\n",
-      "merge": "json"
+      "content": "{}\n"
     },
     {
       "id": "runtime",
@@ -118,7 +119,7 @@
     }
   },
   "binds": {
-    "route": "/var/lib/searxng-module/route.json"
+    "route": "${dir:state}/route.json"
   },
   "build": {
     "on": [