Updated Design: Runnable Project (markdown)

Design:-Runnable-Project.md

@@ -16,14 +16,15 @@ It should be possible to deploy a project without using the editor. For example:
 We can't quite do this today. Here are the missing pieces:
 
 1. the project's `package.json` needs to list `node-red` as a dependency. On balance, I think this is the right approach, rather than treat node-red as an assumed prerequisite. I don't think we should do this be default; maybe add a checkbox in the project settings' dependencies page to include `node-red`.
-> DCJ: Yes - agree it should be a dependency. Currently not hard to add manually, but could be even easier.
+> DCJ: Yes - agree it should be a dependency. Currently not hard to add manually, but could be even easier. It would be a prerequisite dependency for inside a Docker container.
 2. it must be possible to point node-red at a project on start-up, without using the editor to do so. Currently we overload the flowFile argument to set the active project - but that only works if the project is 'known'. It would be better to point at a `projectDir` wherever it may exist.
-> 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)
+> 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 projectDir)
+> DCJ: Having played with it a while - I think `npm start` from within the relevant directory is the way to go to start with.
 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="..."`
-      - [DCJ] added as option to runnable-project dev branch
+      - [DCJ] added as new command line option to runnable-project dev branch
 
 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 
     - just handling the error. 
@@ -31,10 +32,10 @@ We can't quite do this today. Here are the missing pieces:
     - setting disableEditor to `true` also.
 
 The package would provide an npm start script that runs node-red with the appropriate command-line args.
-It could also provide a `bin` section that could allow starting via command line if installed globally.
 
 > DCJ: If you run the steps above then node-red and other modules will be installed *below* the CWD in node_modules... all good.  If however we want to take our project dir and npm pack it... on re-installing it the project itself will also be in the node_modules dir thus making npm start (or pathing back to node-red) trickier.
-Another possibility would be to add a bin section to package.json - but that requires a command to be run (and doesn't take parameters) so in order to do that we would also need to create that script/.js file or porvide a template.
+
+It could also provide a `bin` section that could allow starting via command line if installed globally - but that requires a command to be run (that doesn't take parameters) so in order to do that we would also need to create that script/.js file or provide a template.
 
 > DCJ: Actually by pre-req node-red it automatically adds the node-red command to the node_modules/.bin so the package.json start script can just call node-red and all is good.
 
@@ -56,7 +57,7 @@ We should also have an example Dockerfile that can be used to build and run a pr
 
 > DCJ: Here is an example *Dockerfile.template* that works with various flavours of Docker - note that the flow file is set using the start command in package.json, and it needs node red as a dependency)
 
-    "scripts": {"start": "node node_modules/node-red/red.js flow.json"},
+    "scripts": {"start": "node-red -u . flow.json"},
 
 ```
 # Expects -e NODE_RED_CREDENTIAL_SECRET="my_secret_key" to be part of the docker run command at start time
@@ -85,7 +86,9 @@ RUN JOBS=MAX npm install --production --unsafe-perm --no-optional && npm cache c
 
 COPY . ./
 
+# required for Resin.io
 ENV INITSYSTEM on
+# useful for pigpiod node to be able to talk to daemon on host.
 ENV HOST_IP=172.17.0.1
 ENV NODE_PATH=/usr/src/app/node_modules
 
@@ -96,7 +99,8 @@ CMD ["npm", "start"]
 
 A really minimal Dockerfile to build an image (but not run) could be as simple as
 
-```FROM node:8-onbuild
+```
+FROM node:8-onbuild
 VOLUME /root/.node-red
 EXPOSE 1880
 ```