contrib: add etcd cluster deploy on systemd docs

Fix https://github.com/coreos/etcd/issues/5971

contrib/README.md

@@ -5,3 +5,4 @@ Scripts and files which may be useful but aren't part of the core etcd project.
 * [systemd](systemd) - an example unit file for deploying etcd on systemd-based distributions
 * [raftexample](raftexample) - an example distributed key-value store using raft
 * [systemd/etcd2-backup-coreos](systemd/etcd2-backup-coreos) - remote backup and restore procedures for etcd2 clusters on CoreOS Linux
+* [systemd/etcd3-multinode](systemd/etcd3-multinode) - multi-node cluster setup with systemd

contrib/systemd/etcd3-multinode/README.md

@@ -0,0 +1,173 @@
+# etcd3 multi-node cluster
+
+Here's how to deploy etcd cluster with systemd.
+
+## Set up data directory
+
+etcd needs data directory on host machine. Configure the data directory accessible to systemd as:
+
+```
+sudo mkdir -p /var/lib/etcd
+sudo chown -R root:$(whoami) /var/lib/etcd
+sudo chmod -R a+rw /var/lib/etcd
+```
+
+## Write systemd service file
+
+In each machine, write etcd systemd service files:
+
+```
+cat > /tmp/my-etcd-1.service <<EOF
+[Unit]
+Description=etcd
+Documentation=https://github.com/coreos/etcd
+Conflicts=etcd.service
+Conflicts=etcd2.service
+
+[Service]
+Type=notify
+Restart=always
+RestartSec=5s
+LimitNOFILE=40000
+TimeoutStartSec=0
+
+ExecStart=etcd --name my-etcd-1 \
+    --data-dir /var/lib/etcd \
+    --listen-client-urls http://${IP_1}:2379 \
+    --advertise-client-urls http://${IP_1}:2379 \
+    --listen-peer-urls http://${IP_1}:2380 \
+    --initial-advertise-peer-urls http://${IP_1}:2380 \
+    --initial-cluster my-etcd-1=http://${IP_1}:2380,my-etcd-2=http://${IP_2}:2380,my-etcd-3=http://${IP_3}:2380 \
+    --initial-cluster-token my-etcd-token \
+    --initial-cluster-state new
+
+[Install]
+WantedBy=multi-user.target
+EOF
+sudo mv /tmp/my-etcd-1.service /etc/systemd/system/my-etcd-1.service
+```
+
+```
+cat > /tmp/my-etcd-2.service <<EOF
+[Unit]
+Description=etcd
+Documentation=https://github.com/coreos/etcd
+Conflicts=etcd.service
+Conflicts=etcd2.service
+
+[Service]
+Type=notify
+Restart=always
+RestartSec=5s
+LimitNOFILE=40000
+TimeoutStartSec=0
+
+ExecStart=etcd --name my-etcd-2 \
+    --data-dir /var/lib/etcd \
+    --listen-client-urls http://${IP_2}:2379 \
+    --advertise-client-urls http://${IP_2}:2379 \
+    --listen-peer-urls http://${IP_2}:2380 \
+    --initial-advertise-peer-urls http://${IP_2}:2380 \
+    --initial-cluster my-etcd-1=http://${IP_1}:2380,my-etcd-2=http://${IP_2}:2380,my-etcd-3=http://${IP_3}:2380 \
+    --initial-cluster-token my-etcd-token \
+    --initial-cluster-state new
+
+[Install]
+WantedBy=multi-user.target
+EOF
+sudo mv /tmp/my-etcd-2.service /etc/systemd/system/my-etcd-2.service
+```
+
+```
+cat > /tmp/my-etcd-3.service <<EOF
+[Unit]
+Description=etcd
+Documentation=https://github.com/coreos/etcd
+Conflicts=etcd.service
+Conflicts=etcd2.service
+
+[Service]
+Type=notify
+Restart=always
+RestartSec=5s
+LimitNOFILE=40000
+TimeoutStartSec=0
+
+ExecStart=etcd --name my-etcd-3 \
+    --data-dir /var/lib/etcd \
+    --listen-client-urls http://${IP_3}:2379 \
+    --advertise-client-urls http://${IP_3}:2379 \
+    --listen-peer-urls http://${IP_3}:2380 \
+    --initial-advertise-peer-urls http://${IP_3}:2380 \
+    --initial-cluster my-etcd-1=http://${IP_1}:2380,my-etcd-2=http://${IP_2}:2380,my-etcd-3=http://${IP_3}:2380 \
+    --initial-cluster-token my-etcd-token \
+    --initial-cluster-state new
+
+[Install]
+WantedBy=multi-user.target
+EOF
+sudo mv /tmp/my-etcd-3.service /etc/systemd/system/my-etcd-3.service
+```
+
+## Start the service
+
+The service needs to be enabled first, in case of system reboot:
+
+```
+sudo systemctl daemon-reload
+sudo systemctl enable my-etcd-1.service
+sudo systemctl start my-etcd-1.service
+```
+
+```
+sudo systemctl daemon-reload
+sudo systemctl enable my-etcd-2.service
+sudo systemctl start my-etcd-2.service
+```
+
+```
+sudo systemctl daemon-reload
+sudo systemctl enable my-etcd-3.service
+sudo systemctl start my-etcd-3.service
+```
+
+## Check logs
+
+systemd stores etcd server logs with journald:
+
+```
+sudo systemctl status my-etcd-1.service -l --no-pager
+sudo journalctl -u my-etcd-1.service -l --no-pager|less
+sudo journalctl -f -u my-etcd-1.service
+```
+
+```
+sudo systemctl status my-etcd-2.service -l --no-pager
+sudo journalctl -u my-etcd-2.service -l --no-pager|less
+sudo journalctl -f -u my-etcd-2.service
+```
+
+```
+sudo systemctl status my-etcd-3.service -l --no-pager
+sudo journalctl -u my-etcd-3.service -l --no-pager|less
+sudo journalctl -f -u my-etcd-3.service
+```
+
+## Stop etcd
+
+To disable etcd process:
+
+```
+sudo systemctl stop my-etcd-1.service
+sudo systemctl disable my-etcd-1.service
+```
+
+```
+sudo systemctl stop my-etcd-2.service
+sudo systemctl disable my-etcd-2.service
+```
+
+```
+sudo systemctl stop my-etcd-3.service
+sudo systemctl disable my-etcd-3.service
+```