#! /bin/bash

. /usr/src/m2/framework/settings.sh
. /usr/src/m2/framework/bash_functions.sh


# ---- VARS -----

VERSION="1.1.4"
SCRIPT_NAME="Prometheus/Grafana install"

# Supports Centos 7 and Centos 8

# ---- MAIN -----

k_start

_centos_version
if (( centos_version > 6 )); then
    report "Centos: $centos_version" 0
else
    report "Wrong Centos version: $centos_version. Script can only be run on Centos 7/8"
    k_exit 1
fi


# --- Prometheus ---

# maybe it's already installed?
if [[ -d "/home/prometheus" ]]
then
  report "Prometheus is already installed" 3
  #/bin/systemctl status prometheus | grep 'Active\|Prometheus Server'
  #/bin/systemctl status grafana-server.service | grep 'Active\|Grafana instance'
  k_exit 0
fi

report "Installing dependencies" 3
yum -y install net-tools wget firewalld tar sqlite

# making sure firewall is up
systemctl start firewalld
systemctl enable firewalld

if (systemctl -q is-active firewalld.service); then
    report "Firewalld is active" 0
else
    report "Firewalld is not active" 1
    k_exit 1
fi


# Selinux off
cd /usr/src/m2/maintenance
./selinux_disable.sh

# Time-sync (currently fails on C8)
if (( centos_version == 7 )); then
    ./time_sync.sh
fi

report "Installing Prometheus" 3

# check newest prometheus version here: https://github.com/prometheus/prometheus/releases
version="2.22.0"

cd /usr/src/
wget https://github.com/prometheus/prometheus/releases/download/v$version/prometheus-$version.linux-amd64.tar.gz
tar -xzvf prometheus-$version.linux-amd64.tar.gz
mv prometheus-$version.linux-amd64/ prometheus/

mkdir /home/prometheus
mv /usr/src/prometheus /home/prometheus/prometheus

# configure Systemd Service

cd /etc/systemd/system/
touch prometheus.service

cat << 'EOF' > /etc/systemd/system/prometheus.service

[Unit]
Description=Prometheus Server
Documentation=https://prometheus.io/docs/introduction/overview/
After=network-online.target

[Service]
User=root
Restart=on-failure

ExecStart=/home/prometheus/prometheus/prometheus \
  --config.file=/home/prometheus/prometheus/prometheus.yml \
  --storage.tsdb.path=/home/prometheus/prometheus/data

[Install]
WantedBy=multi-user.target

EOF

/bin/systemctl start prometheus
/bin/systemctl enable prometheus


# sane location for prometheus config
mkdir -p /etc/prometheus
ln -s /home/prometheus/prometheus/prometheus.yml /etc/prometheus/prometheus.yml


# is it running?

if (systemctl -q is-active prometheus.service); then
    report "Prometheus is active" 0
else
    report "Prometheus is not active" 1
    k_exit 1
fi

netstat -plntu | grep prometheus


# --- Grafana ---

report "Installing Grafana" 3


# newest version: https://grafana.com/grafana/download
# over there: Red Hat, CentOS, RHEL, and Fedora(64 Bit) SHA256:
# wget https://dl.grafana.com/oss/release/grafana-7.2.2-1.x86_64.rpm
grafana_version="7.2.2-1"

yum -y install initscripts urw-fonts fontconfig freetype*
cd /usr/src/
wget https://dl.grafana.com/oss/release/grafana-$grafana_version.x86_64.rpm
yum -y localinstall grafana-$grafana_version.x86_64.rpm


/bin/systemctl daemon-reload
/bin/systemctl enable grafana-server.service
/bin/systemctl start grafana-server.service

if (systemctl -q is-active grafana-server.service); then
    report "Grafana is active" 0
else
    report "Grafana is not active" 1
    k_exit 1
fi

report "Configuring Grafana" 3

# add Prometheus as data-source

sleep 2 # to avoid "database is locked"
cat <<EOF | sqlite3 /var/lib/grafana/grafana.db || echo "Failed to add data source."
INSERT INTO data_source VALUES (2,1,0,'prometheus','Prometheus','proxy','http://localhost:9090',NULL,NULL,NULL,0,NULL,NULL,1,'{"httpMethod":"GET","keepCookies":[]}','2017-01-15 20:00:00','2017-01-15 20:00:00',0,'{}',NULL,1);
EOF


# open access from outside
firewall-cmd --add-port=3000/tcp --permanent
firewall-cmd --reload

# access with IP:3000, default login: admin/admin

k_exit 0