Publish on host loopback for NPMplus with host networking

NPMplus runs with network_mode: host, so it cannot reach the container by
name on a shared Docker network. Publish the app on 127.0.0.1:4181 instead
and drop the NPM_NETWORK setting.

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

.env.example

@@ -1,8 +1,10 @@
 # Stack settings. In Portainer, enter these under the stack's "Environment variables".
 # For the docker compose CLI, copy this file to .env next to compose.yaml. Never commit the completed file.
 
-# Docker network Nginx Proxy Manager is attached to (Portainer > Networks shows the name).
-NPM_NETWORK=npm_default
+# Host port the app listens on, bound to loopback so only NPMplus (host networking) can reach it.
+# Change PROPOSAL_BOT_PORT if 4181 is already taken on the host.
+PROPOSAL_BOT_BIND=127.0.0.1
+PROPOSAL_BOT_PORT=4181
 
 # Absolute host folders. The data folder must be writable by UID 1000.
 PROPOSAL_BOT_DATA_HOST_PATH=/opt/proposal-bot/data

README.md

@@ -14,7 +14,7 @@ The image contains only the app code and Chromium (used by the InDesign export).
 
 ## Deploy with Portainer
 
-The stack has no published port. Nginx Proxy Manager (NPM) handles HTTPS and reaches the container by name over NPM's Docker network.
+NPMplus handles HTTPS. It runs with host networking, so the container publishes its port on the host's loopback address only (`127.0.0.1:4181`). NPMplus can reach that port; other machines cannot.
 
 ### 1. Put the project and photo folders on the Docker host
 
@@ -29,7 +29,7 @@ sudo chown -R 1000:1000 /opt/proposal-bot/data    # the container runs as UID 10
 ### 2. Create the Microsoft Entra app registration
 
 1. Create a web app registration for Proposal Bot with a client secret.
-2. Register the callback `https://<proposal-bot-hostname>/auth/microsoft/callback`, using the hostname NPM will serve.
+2. Register the callback `https://<proposal-bot-hostname>/auth/microsoft/callback`, using the hostname NPMplus will serve.
 
 ### 3. Create the stack
 
@@ -38,16 +38,16 @@ In Portainer, go to **Stacks > Add stack > Repository**:
 - **Repository URL:** this repo's Gitea URL. Turn on **Authentication** and use a Gitea access token if the repo is private.
 - **Compose path:** `compose.yaml`
 - **Environment variables:** add every entry from `.env.example`. **Advanced mode** accepts the whole file pasted in.
-  - `NPM_NETWORK`: the network NPM's container is attached to. To find it, open NPM's container in Portainer and look at its network section, usually something like `npm_default`.
+  - `PROPOSAL_BOT_PORT`: leave at `4181` unless that port is already in use on the host.
   - `PROPOSAL_BOT_DATA_HOST_PATH` and `PROPOSAL_BOT_PROJECT_IMAGES_HOST_PATH`: the folders from step 1. Use absolute paths. A relative path would end up inside Portainer's copy of the repo and be lost on redeploy.
   - `MICROSOFT_REDIRECT_URI`: exactly the callback from step 2.
 
 Deploy the stack. Portainer builds the image on the host, which takes a few minutes the first time because it installs Chromium. The container should show **healthy**. Its logs show startup warnings, such as missing sign-in settings or a `data` folder the container cannot write to.
 
-### 4. Add the NPM proxy host
+### 4. Add the NPMplus proxy host
 
 - **Domain:** the Proposal Bot hostname
-- **Forward:** scheme `http`, hostname `proposal-bot`, port `4181`
+- **Forward:** scheme `http`, hostname `127.0.0.1`, port `4181` (or your `PROPOSAL_BOT_PORT`)
 - **SSL tab:** request or choose a certificate, and turn on **Force SSL**
 - **Advanced tab:** paste the lines below so long InDesign exports are not cut off after 60 seconds:
 
@@ -68,7 +68,7 @@ Copy `.env.example` to `.env`, fill it in, and run `docker compose up -d --build
 
 ## Sign-in
 
-Sign-in uses Microsoft Entra and the email allowlist in `PROPOSAL_BOT_ALLOWED_EMAILS` (comma-separated). Microsoft only accepts HTTPS callbacks, which NPM provides.
+Sign-in uses Microsoft Entra and the email allowlist in `PROPOSAL_BOT_ALLOWED_EMAILS` (comma-separated). Microsoft only accepts HTTPS callbacks, which NPMplus provides.
 
 Sessions are kept in memory, so restarting or redeploying the container signs everyone out.
 

compose.yaml

@@ -9,9 +9,10 @@ services:
     restart: unless-stopped
     # Reaps the headless Chromium processes the InDesign export starts.
     init: true
-    # No published port: Nginx Proxy Manager reaches http://proposal-bot:4181 over its Docker network.
-    networks:
-      - proxy
+    # Published on the host's loopback only. NPMplus (host networking) forwards to http://127.0.0.1:4181;
+    # other machines cannot reach the port directly.
+    ports:
+      - "${PROPOSAL_BOT_BIND:-127.0.0.1}:${PROPOSAL_BOT_PORT:-4181}:4181"
     environment:
       HOST: 0.0.0.0
       PORT: 4181
@@ -33,8 +34,3 @@ services:
         source: ${PROPOSAL_BOT_PROJECT_IMAGES_HOST_PATH:?Set PROPOSAL_BOT_PROJECT_IMAGES_HOST_PATH to an absolute host folder for the photo library}
         target: /app/Project Images
         read_only: true
-
-networks:
-  proxy:
-    external: true
-    name: ${NPM_NETWORK:?Set NPM_NETWORK to the Docker network Nginx Proxy Manager is attached to}