Create a way to have the hostname be auto-generated

[peerst]

Description

Starting the same release on multiple GRiSP boards connected to the same Wifi should be more easy. We should use a autogenerated hostname derived from the serial number (which is somewhere in the EEPROM if I remember correctly).

e.g. board with serial number 123 might get hostname grisp0123

In addition we could make the hostname a optional argument for rebar3 grisp {deploy|build}

Also make this work with GRiSP 2 boards (maybe we just continue serial numbers there)

[eproxus]

There is a workaround for setting the hostname as an argument to deploy:

It's possible to use environment variables in the templates. So one could do the following:

[network]
{{#env.GRISP_HOSTNAME}}
hostname={{env.GRISP_HOSTNAME}}
{{/env.GRISP_HOSTNAME}}

And then run deploy:

$ GRiSP_HOSTNAME=foobar rebar3 grisp deploy ...

[Laymer]

Hello :)

I might be able to provide some help for this, as I have been helped by @pedroAkos for the Yggdrasil integration that derives an IP based on the hwaddr of a GRiSP board. Currently I have the following output at boot time :

Interface MAC address is 38:1d:d9:46:2d:e6
INFO: CONNECTING TO INTERFACE -> 'wlan0'
Hostname -> '169-254-215-181'
Interface: wlan0        Address: 169.254.215.181
Ip address -> '169.254.215.181'
starting erlang runtime
Eshell V10.0  (abort with ^G)
(achlys@169-254-215-181)1> node().
'achlys@169-254-215-181'
(achlys@169-254-215-181)2> 1988-01-01T00:10:41.993428+00:00 critical: Formation result : {ok,['achlys@169-254-215-181']}
(achlys@169-254-215-181)2> inet:getifaddrs().
{ok,[{"lo0",
      [{flags,[up,loopback,running,multicast]},
       {addr,{127,0,0,1}},
       {netmask,{255,255,255,0}}]},
     {"wlan0",
      [{flags,[up,broadcast,running,multicast]},
       {addr,{169,254,215,181}},
       {netmask,{255,255,0,0}},
       {broadaddr,{169,254,255,255}}]}]}

In the output above the hostname is "169-254-215-181" but it could be certainly changed to something else (this was only for debugging). But I have just tested it and I am able to connect my laptop to that board and send/receive messages using gen_udp. So if this is something that might be useful feel free to let me know 🙂

PS : thanks @eproxus for the deployment trick !