#!/bin/bash
# Very simple systemd unit generator for etcd & vitastor-mon services
# Not the final solution yet, mostly for tests
# Copyright (c) Vitaliy Filippov, 2019+
# License: MIT

# USAGE: ./make-units.sh

IP_SUBSTR="10.200.1."
ETCD_HOSTS="etcd0=http://10.200.1.10:2380,etcd1=http://10.200.1.11:2380,etcd2=http://10.200.1.12:2380"

# determine IP
IP=`ip -json a s | jq -r '.[].addr_info[] | select(.local | startswith("'$IP_SUBSTR'")) | .local'`
[ "$IP" != "" ] || exit 1
ETCD_NUM=${ETCD_HOSTS/$IP*/}
[ "$ETCD_NUM" != "$ETCD_HOSTS" ] || exit 1
ETCD_NUM=$(echo $ETCD_NUM | tr -d -c , | wc -c)

# etcd
useradd etcd

mkdir -p /var/lib/etcd$ETCD_NUM.etcd
cat >/etc/systemd/system/etcd.service <<EOF
[Unit]
Description=etcd for vitastor
After=network-online.target local-fs.target time-sync.target
Wants=network-online.target local-fs.target time-sync.target

[Service]
Restart=always
ExecStart=/usr/local/bin/etcd -name etcd$ETCD_NUM --data-dir /var/lib/etcd$ETCD_NUM.etcd \\
    --advertise-client-urls http://$IP:2379 --listen-client-urls http://$IP:2379 \\
    --initial-advertise-peer-urls http://$IP:2380 --listen-peer-urls http://$IP:2380 \\
    --initial-cluster-token vitastor-etcd-1 --initial-cluster $ETCD_HOSTS \\
    --initial-cluster-state new --max-txn-ops=100000 --max-request-bytes=104857600 \\
    --auto-compaction-retention=10 --auto-compaction-mode=revision
WorkingDirectory=/var/lib/etcd$ETCD_NUM.etcd
ExecStartPre=+chown -R etcd /var/lib/etcd$ETCD_NUM.etcd
User=etcd
PrivateTmp=false
TasksMax=infinity
Restart=always
StartLimitInterval=0
RestartSec=10

[Install]
WantedBy=local.target
EOF

systemctl daemon-reload
systemctl enable etcd
systemctl start etcd

useradd vitastor
chmod 755 /root

# Vitastor target
cat >/etc/systemd/system/vitastor.target <<EOF
[Unit]
Description=vitastor target
[Install]
WantedBy=multi-user.target
EOF

# Monitor unit
ETCD_MON=$(echo $ETCD_HOSTS | perl -pe 's/:2380/:2379/g; s/etcd\d*=//g;')
cat >/etc/systemd/system/vitastor-mon.service <<EOF
[Unit]
Description=Vitastor monitor
After=network-online.target local-fs.target time-sync.target
Wants=network-online.target local-fs.target time-sync.target

[Service]
Restart=always
ExecStart=node /usr/lib/vitastor/mon/mon-main.js --etcd_url '$ETCD_MON' --etcd_prefix '/vitastor' --etcd_start_timeout 5
WorkingDirectory=/
User=vitastor
PrivateTmp=false
TasksMax=infinity
Restart=always
StartLimitInterval=0
RestartSec=10

[Install]
WantedBy=vitastor.target
EOF