Title: How to parallelize Drist
       Author: Solène
       Date: 06 February 2019
       Tags: drist automation unix
       Description: 
       
       This article will show you how to make drist faster by using it on
       multiple
       servers at the same time, in a correct way. 
       
       [What is
       drist?](https://dataswamp.org/~solene/2018-11-29-drist-intro.html)
       
       It is easily possible to parallelize drist (this works for everything
       though)
       using Makefile. I use this to deploy a configuration on my servers at
       the same
       time, this is way faster.
       
       A simple BSD Make compatible Makefile looks like this:
       
           SERVERS=tor-relay.local srvmail.tld srvmail2.tld
           ${SERVERS}:
                   drist $*
           install: ${SERVERS}
           .PHONY: all install ${SERVERS}
       
       This create a target for each server in my list which will call drist.
       Typing
       `make install` will iterate over `$SERVERS` list but it is so possible
       to use
       `make -j 3` to tell make to use 3 threads. The output may be mixed
       though.
       
       You can also use `make tor-relay.local` if you don't want make to
       iterate over
       all servers. This doesn't do more than typing `drist tor-relay.local`
       in the
       example, but your Makefile may do other logic before/after.
       
       If you want to type `make` to deploy everything instead of `make
       install` you
       can add the line `all: install` in the Makefile.
       
       If you use GNU Make (gmake), the file requires a small change:
       
       The part `${SERVERS}:` must be changed to `${SERVERS}: %:`, I think
       that gmake
       will print a warning but I did not succeed with better result. If you
       have the
       solution to remove the warning, please tell me.
       
       If you are not comfortable with Makefiles, the .PHONY line tells *make*
       that
       the targets are not valid files.
       
       Make is awesome!