* add the command to create `/usr/local/lib/moonfire-nvr`, necessary
the first time
* have the files owned by root and use world-readable permissions, even
if the building user has a restrictive umask set
* run node 12, 14, and 16 (next to be supported) on CI. This will catch
node version-specific problems like that solved in dad9bdc.
* mention 12 and 14 in build instructions and link to instructions for
installing that version.
* follow this in Dockerfile, installing version 14. This addresses
a "Cannot find module 'worker_threads'" error introduced in
39a63e0, which (inadvisedly) upgraded gzipper 4->5 in addition to
the material-ui upgrade.
* use utf-8 encoding rather than ascii in live part parser. Those
builds apparently don't support ascii. iThey must use "small-icu" or
have ICU disabled, as described here:
https://nodejs.org/api/util.html#util_encodings_supported_when_node_js_is_built_with_the_small_icu_option
This eases build setup. Where Yarn requires a separate package
repository, npm is available in the standard one.
yarn's package repository signature was recently expired, and apparently
will expire again in a year. Avoid dealing with that.
Fixes#110.
Besides being more clear about what belongs to which, this helps with
docker caching. The server and ui parts are only rebuilt when their
respective subdirectories change.
Extend this a bit further by making the webpack build not depend on
the target architecture. And adding cache dirs so parts of the server
and ui build process can be reused when layer-wide caching fails.
