Updated Design: Runnable Project (markdown)

Design:-Runnable-Project.md

@@ -19,6 +19,7 @@ We can't quite do this today. Here are the missing pieces:
 > DCJ: Are we pointing Node-RED or npm start ? Which are we calling to run it ? If npm start then don't we already have to be in the correct project directory ? (or use npm start --prefix projdir)
 3. it must be possible to provide the credentialSecret for the project without it being part of any of the version controlled files. Options for this include:
     - env var - `NODE_RED_CREDENTIAL_SECRET`
+      - [DCJ] easy to add to settings.js - `credentialSecret: process.env.NODE_RED_CREDENTIAL_SECRET` and would suit Docker style deploy.
     - command-line flag - `--credentialSecret="..."`
 
 4. Must handle running in a read-only environment. If the package is installed globally (in order to insert a command link into /usr/bin) then the flow file and settings.js will be in root space - which ought not to be writable by the user. Currently even starting Node-RED with -u option pointing somewhere protected will fail. Options include 
@@ -34,7 +35,14 @@ It could also provide a `bin` section that could allow starting via command line
 ### Runtime settings
 
 When deploying the project, there will also be a need to have the runtime settings provided. These are not normally part of a project generated by Node-RED. The question is whether we have some tooling support to generate, or we just document how to do it. For example, the user would manually add a `settings.js` file to their project repo.
-> DCJ: If we have the "add node-red as a dependency" checkbox - could it not also... "copy default settings.js into project" ? (but ensuring flowFile doesn't clash)
+> DCJ: If we have the "add node-red as a dependency" checkbox - could it not also... "copy default settings.js into project" or create a minimal settings.js (i.e. without defaults and comments) ? (but ensuring flowFile doesn't clash) e.g.
+    
+```
+module.exports = {
+    uiPort: process.env.PORT || 1880,
+    credentialSecret: process.env.NODE_RED_CREDENTIAL_SECRET
+}
+```
 
 
 ### Credentials
@@ -55,7 +63,13 @@ We should also have an example Dockerfile that can be used to build and run a pr
 # and about resin base images here: http://docs.resin.io/runtime/resin-base-images/
 # Note the node:slim image doesn't have node-gyp
 
-FROM resin/%%RESIN_MACHINE_NAME%%-node:8-slim
+## Uncomment one of the following FROM lines to suit your environment
+# For generic servers
+#FROM node:8-slim
+# For Pi...
+FROM arm32v7/node:8-slim
+# For Resin.io
+#FROM resin/%%RESIN_MACHINE_NAME%%-node:8-slim
 
 # Uncomment the next three lines if you want GPIO for Pi
 #RUN apt-get update && apt-get install -yq \
@@ -71,6 +85,7 @@ RUN JOBS=MAX npm install --production --unsafe-perm --no-optional && npm cache c
 COPY . ./
 
 ENV INITSYSTEM on
+ENV HOST_IP=172.17.0.1
 ENV NODE_PATH=/usr/src/app/node_modules
 
 EXPOSE 1880