configure systemd service restart and increase file descriptors limit for Linode script (#320)

scripts/smp-server-digitalocean-droplet/README.md

@@ -16,3 +16,8 @@ brew install hashicorp/tap/packer
 cd ./scripts/smp-server-digitalocean-droplet
 DIGITALOCEAN_TOKEN=$YOUR_TOKEN packer build -on-error=ask -color=false ./marketplace-image.json
 ```
+
+**TODO** (see Linode script)
+
+- Increase file descriptors limit
+- Configure Restart for systemd service

scripts/smp-server-linode.sh

@@ -44,6 +44,12 @@ ufw allow ssh
 ufw allow https
 ufw allow 5223
 
+# Increase file descriptors limit
+echo 'fs.file-max = 1000000' >> /etc/sysctl.conf
+echo 'fs.inode-max = 1000000' >> /etc/sysctl.conf
+echo 'root soft nofile unlimited' >> /etc/security/limits.conf
+echo 'root hard nofile unlimited' >> /etc/security/limits.conf
+
 # Download latest release
 bin_dir="/opt/simplex/bin"
 binary="$bin_dir/smp-server"
@@ -151,6 +157,10 @@ Description=SMP server
 [Service]
 Type=simple
 ExecStart=/bin/sh -c "exec $binary start >> /var/opt/simplex/smp-server.log 2>&1"
+Restart=always
+RestartSec=10
+LimitNOFILE=1000000
+LimitNOFILESoft=1000000
 
 [Install]
 WantedBy=multi-user.target