n8n runs its upstream image with uuid mounted and the media group joined, in place of a Dockerfile (issue 1639, ADR 0480 clauses 1, 3, 7, 8)

modules/n8n/Dockerfile

@@ -1,20 +0,0 @@
-# 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/README.md

@@ -1,6 +1,10 @@
 # n8n
 
-The `n8n` module of the mesh catalogue: runs the container image `redis`; runs the container image `selenium/standalone-chrome`.
+The `n8n` module of the mesh catalogue: runs the upstream image `n8nio/n8n` by digest with the `uuid` package mounted into it (ADR 0480 clauses 1, 3, 7 and 8); runs the container image `redis`; runs the container image `selenium/standalone-chrome`.
+
+- The `server` container no longer comes from a Dockerfile. Its program is the upstream image's, bit for bit the one the module built on before (digest `4846eb2f...`; the running container reports release 1.71.3).
+- `uuid` 14.0.1, which Code nodes `require`, is fetched once by its pinned sha256 from the package registry and mounted read-only at `/usr/local/lib/node_modules/uuid` (where `npm install -g` put it in the image the module built).
+- The server joins the media library's group as a supplementary group, `groups` from the config key `media-gid`; the key has no default, so a machine that does not say it refuses n8n.
 
 ## Files it does not know
 
@@ -8,4 +12,5 @@ Each directory or archive this module declares says how it treats a file it did
 
 - `${dir:state}`: everything in it is the program's; the mesh moves nothing out (ADR 0422 §2).
 - `${dir:data}`: everything in it is the program's; the mesh moves nothing out (ADR 0422 §2).
+- `${dir:state}/uuid`: everything in it is the program's; the mesh moves nothing out (ADR 0422 §2).
 - `${dir:cache}`: everything in it is the program's; the mesh moves nothing out (ADR 0422 §2).

modules/n8n/module.json

@@ -30,6 +30,14 @@
       "mode": "read-write"
     }
   ],
+  "config": {
+    "media-gid": {
+      "type": "number",
+      "description": "The number of the group that owns the media library on this machine, which the server joins as a supplementary group so a workflow can file into the library (novox/hq ADR 0480 clause 7). Set per machine; until the container takes it from the media library itself (issue 1618) nothing writes a default, so a machine that does not say it refuses n8n by name.",
+      "minimum": 1,
+      "trusted": true
+    }
+  },
   "listens": [
     {
       "name": "web",
@@ -92,6 +100,13 @@
       "mode": "0600",
       "template": "files/server.env"
     },
+    {
+      "id": "uuid",
+      "type": "archive",
+      "path": "${dir:state}/uuid",
+      "artifact": "uuid",
+      "unknown": "program"
+    },
     {
       "id": "net",
       "type": "network",
@@ -119,7 +134,11 @@
       "volumes": [
         "${dir:data}:/home/node/.n8n",
         "${dir:state}/n8n-database.secret:/run/secrets/database:ro",
+        "${dir:state}/uuid:/usr/local/lib/node_modules/uuid:ro",
         "${access:media}:/media-library"
+      ],
+      "groups": [
+        "${config:media-gid}"
       ]
     },
     {
@@ -151,17 +170,22 @@
     }
   ],
   "build": {
-    "on": [
-      {
-        "arg": "N8N_BASE",
-        "image": "n8nio/n8n@sha256:4846eb2f4b874ab04cde7fc1e249d2ddaec66e9aea64439beb2972cfea88e3c0"
-      }
-    ],
     "artifacts": [
       {
         "name": "server",
-        "kind": "image",
-        "from": "Dockerfile"
+        "kind": "upstream",
+        "from": "n8nio/n8n@sha256:4846eb2f4b874ab04cde7fc1e249d2ddaec66e9aea64439beb2972cfea88e3c0"
+      },
+      {
+        "name": "uuid",
+        "kind": "archive",
+        "url": "https://registry.npmjs.org/uuid/-/uuid-14.0.1.tgz",
+        "sha256": "e062c57ed120ea135478f305da04802bf69eab23fbc0ca2bae6989b6855390c4",
+        "version": "14.0.1",
+        "within": "package",
+        "names-on-purpose": {
+          "registry.npmjs.org": "the npm registry publishes the uuid package there; the build seat fetches it once, by its pinned sha256 (novox/hq ADR 0316 §2, ADR 0480 §8)"
+        }
       },
       {
         "name": "files",