When adding Routes to zerotier's Managed Routes, the helper will
add a route rule to the device that does not have a via ip,
so that the address of the Destination segment cannot be routed
correctly within the container.
Here, based on the contents of the routes key in
`zerotier-cli -j listnetworks`,
by determining whether the via key has an ip address,
if it is not null, helper will no longer add route rules.
* update entrypoint.sh
- propagate TERM/QUIT/INT signals
- add some basic logging
- check for unbound variables
- update "route helper"
- run as subshell, exit if zerotier-one is unavailable so pod can be restarted
- only call `zerotier-cli` once, avoids race conditions
- only add default routes if allowDefault is enabled for that network
- add some more error handling
- sleep after all networks are processed
* switch to polling ZT service at startup
Co-authored-by: Daniel Quinlan <dq@chaosengine.net>
