linux

I already have some iPXE infra to boot/deploy VMs and bare metal hosts. But it is more Debian/CentOS centric and I decided to throw Alpine Linux into the mix. Integration was suprisingly easy. boot.alpinelinux.org has good set of resources. Especially nice is that UEFI images are signed. The simplest solution was just to chainload single boot.ipxe. chain -ar http://boot.alpinelinux.org/boot.ipxe || More robust version could be something like this: #!ipxe set alpine-repo http://dl-cdn....

GNU Parallel is bundled with sem which is according to man is alias to parallel --semaphore. It limits number of simultaneously running processes. man sem is pretty simple but full of details and toilet analogies. Complex stuff could be bundled to function. #!/usr/bin/env bash myproc() { local arg="$1" echo "$(date) >>> myproc arg=$arg" sleep "$arg" echo "$(date) <<< myproc arg=$arg" } export -f myproc for i in $(seq 10 1); do sem -j4 myproc "$i" done sem --wait TADAM!...