Offline portable field mapping deployment

[spwoodcock]

Related to #899

We currently have an install script to simplify deployment.

There are two extra requirements:

• Deployment onto a field device, e.g. a raspberry pi that can be taken into the field.
  • Similar to UNVT (offline map server): https://github.com/unvt/portable
  • Side note: could we find a synergy and host both on one Pi?!
• One command deployment.
  • Without a domain name requirement.

Envisioned workflow (entirely offline)

1. Get a raspberry pi and WiFi antennae.
2. Broadcast a WiFi network for users to connect to (via IP, or the device could probably have a nicer domain based routing, e.g. simply field.mapping in the browser).
3. Simple FMTM deployment onto device.
   • Includes a bundled simple tile server (with low resolution world imagery).
   • Includes a bundled ODK Central.
   • No need for Minio?
   • The ODK Central URL would be set to the the device IP/domain.
   • Create a project and QR codes.
   • If the device is online in the office, optional download of basemap tiles.
4. Take device into field.
5. Users connect to WiFi network and then FMTM via IP/domain in browser.
6. Users access the project and get the QR code for their task.
7. Open QR in ODK Collect and map as normal.

Questions

• How to handle OSM Auth if offline?
• How to best serve map via tile server in parallel?
  • Could possible commit basic world tiles to repo, then include in bundled Nginx server.
  • Basemaps required Minio / more complex.

Note: in #899 I discussed the idea of using headscale for a VPN network that users connect to (to avoid requiring a domain).

This proposal is probably a more realistic approach: taking a small offline device into the field to connect to.

One command deployment

• To facilitate the above, we need a streamlined deployment process.
• A domain name is not required, and sane defaults can be provided for most variables.
• The user should be able to run a script and have an FMTM deployment accessible from a URL.