Installation fails when vm.max_map_count doesn't exist

[w-biggs]

Tell us about your setup

v3.0.0-rc.14 on WSL - Ubuntu 18.04.1 LTS.

Tell us about the command you were running

sudo dpkg -i lando-v3.0.0-rc.14.deb

Tell us about the error you got

sysctl: cannot stat /proc/sys/vm/max_map_count: No such file or directory

Max_map_count doesn't exist in WSL - they haven't implemented a dummy version of it like they have with some other /proc/sys/ files.

Tell us more

Wrapping this line in an if statement that checks whether /proc/sys/vm/max_map_count exists fixes the issue and allows Lando to be installed in WSL:

lando/installer/linux/scripts/postinst

Line 22 in 85dc5ff

sysctl -w vm.max_map_count=262144

if [ -f /proc/sys/vm/max_map_count ]; then
  sysctl -w vm.max_map_count=262144
fi

I've confirmed this works and Lando properly installs. I'll submit a pull request with this change.

[pirog]

@w-biggs nice. sorry for the delay here but this seems like a completely reasonable and good change to me. Will def merge it in!