(fix) auto-tune worker_processes

Addresses the fact that nginx uses 1 worker process by default as `auto` will not work correctly in a docker environment.  nginxinc/docker-nginx#31

README.md

@@ -26,3 +26,5 @@ This container provides a nginx with LetsEncypt enabled.  When tested with SSLLa
 ## NOTE
 
 * On first initialization there will be no output for a while, this is because the DHPARAM generation takes quite a bit of time combined with the initial certificate generation.
+* The `worker_processes` value is adjusted automatically to the number of available CPUs from *cgroup*, nginx official image hard codes it to `1`.
+* Due to the nature of nginx and SSL certificates, it is not safe to run this configuration with multiple replicas especially when there are renewals.  The `worker_processes` value is adjusted automatically to the number of available CPUs allocated though so it can handle more load.

init.sh

@@ -27,5 +27,7 @@ fi
 ) 200>/etc/letsencrypt/lock
 
 DOMAIN=$(echo $DOMAINS | cut -d ',' -f 1) envsubst < /etc/nginx/conf.d/default.conf.tmpl > /etc/nginx/conf.d/default.conf
+NUMPROCS=$(cat /sys/fs/cgroup/cpuacct/cpuacct.usage_percpu | wc -w)
+sed -i "s/worker_processes\\s\\+1;/worker_processes ${NUMPROCS};/" /etc/nginx/nginx.conf
 crond
 exec nginx -g "daemon off;"