Code review comment for lp:~free.ekanayaka/landscape-client/release-upgrade-logs

[1] Are we really reading whole files into memory like that? It gives me shivers. We should optimally be generating the message in temporary files and streaming them out on upload if possible, as reading a file of potentially unknown size into memory is a sure way of running into OOM bugs. Failing that, I would go for the 'last N lines' approach right now, instead of waiting until we hit the bug.