Wolfram Cron jobs

As you can see from other posts I can not get the scheduled jobs working in the cloud with any reliability. I have decided to move my jobs to a raspberry pi and run them as cron jobs.

It seems to work reasonably well. The key issues were 1) to boot the pi into graphical user so that a graphics context was available. 2) run the commands with a sudo to pi and then setting the display correct. It appears that a lot of the mathematica code needs a display to process emails.

Eventually with the display I should be able to get Templates working and emailing.

DISPLAY=:0.0  wolfram -script filename

Here is an example cron job. The interesting thing is I pull the cron job down from the web so it is easy to update. Yes it is ugly but it works.

curl www.yyyy.com/wolfram/xxxx.html > xxxxx  ; wolfram -script xxxx

Alternatively You can use a script file just executes wolfram with sticky bit set to pi and has the following

Sample wolfram code (from the website). Note the Quit[] at the end. The reason for the display magic above is that the SendMail seeemed to require a graphics process to manager the GraphicsGrid. My estormSendMail just merges the default association and then calls SendMail[]

ccDestinations = {"blah@fred.com", };
bal = NumberForm[fred`getTelkomcelBalance[]["balance"], {5, 2}];
pinlist = fred`getAvailablePins[];
body = GraphicsGrid[{{Text[Style[StringJoin["Telkomcel Balance ", ToString[bal]], Blue, Bold, 18]]}, {Grid[Prepend[{#, pinlist[#]} & /@ Keys[pinlist], {"Pulsa Type",   "Current Available"}], Frame -> All, Background -> {None, {LightBlue, {LightYellow}}}]}}, ImageSize -> {Small, Large}] ;
estormSendMail[<|"To" -> "fred@fred.com",
"Cc" -> ccDestinations, "From" -> "fred@fred.com",
"Subject" ->
StringJoin["Pulsa balance and pins status ", DateString[]],
"Body" -> body|>];