contrib/systemd: use StateDirectory

Adjust the systemd service to be more similar to other Osmocom
projects, by using StateDirectory. This directory gets created by
systemd, so remove the ExecStartPre=/usr/bin/mkdir line.

Related: https://www.freedesktop.org/software/systemd/man/latest/systemd.exec.html
Change-Id: I83c7749ca1277b71e25c41b4dc943e83608bd442
---
M contrib/systemd/osmo-epdg.service
1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/contrib/systemd/osmo-epdg.service b/contrib/systemd/osmo-epdg.service
index 48ced12..40318c1 100644
--- a/contrib/systemd/osmo-epdg.service
+++ b/contrib/systemd/osmo-epdg.service
@@ -6,10 +6,10 @@
 [Service]
 Type=simple
 Restart=always
-WorkingDirectory=/var/lib/osmo-epdg
+StateDirectory=osmo-epdg
+WorkingDirectory=%S/osmo-epdg
 Environment="ERL_FLAGS=-config /etc/osmocom/osmo-epdg.config"
 ExecStartPre=-/usr/bin/ip link del gtp0
-ExecStartPre=/usr/bin/mkdir -p /var/lib/osmo-epdg
 ExecStart=/usr/bin/osmo-epdg
 RestartSec=2
 

