In systemd: added log files and changed workingdir (#287)

* coredns log configuration for logrotate

In order to not let the log files (wrote in the systemd file) grew too much, we should move this "coredns-log.conf" file inside /etc/logrotate.d/
In this case I set 50MB of logs, splitted in 5 files, rotation occurs every time on file reaches 10MB in size, I also said to compress the file after the rotation, so even less space should be occupied,
you can change this settings with whatever configuration you prefer. :)

* Update README.md

updated readme with instruction with where to move the configuration file for coredns-log.conf

* Update README.md

* changed workingdir and added log files

sometimes using ~ in the workingdir does not work
Also I'd like to print a basic log of what's happening

* update logs in coredns.service

Changed StandardOutput and StandardError from file: to append:
(so when coredns restart logs continue to be printed)

systemd/README.md

@@ -10,3 +10,4 @@ In order to work, you need to do following jobs:
 - Put `Corefile` at `/etc/coredns/Corefile`
 - Put `coredns-sysusers.conf` in `/usr/lib/sysusers.d`
 - Put `coredns-tmpfiles.conf` in `/usr/lib/tmpfiles.d`
+- Put `coredns-log.conf` in `/etc/logrotate.d`

systemd/coredns-log.conf

@@ -0,0 +1,13 @@
+/var/log/coredns.log {
+  rotate 5
+  size 10M
+  compress
+  notifempty
+}
+
+/var/log/coredns.err.log {
+  rotate 5
+  size 10M
+  compress
+  notifempty
+}

systemd/coredns.service

@@ -11,10 +11,13 @@ CapabilityBoundingSet=CAP_NET_BIND_SERVICE
 AmbientCapabilities=CAP_NET_BIND_SERVICE
 NoNewPrivileges=true
 User=coredns
-WorkingDirectory=~
+WorkingDirectory=/var/lib/coredns
 ExecStart=/usr/bin/coredns -conf=/etc/coredns/Corefile
 ExecReload=/bin/kill -SIGUSR1 $MAINPID
 Restart=on-failure
+StandardOutput=append:/var/log/coredns.log
+StandardError=append:/var/log/coredns.err.log
+
 
 [Install]
 WantedBy=multi-user.target