#! /bin/bash

# Run this script on a freshly installed compute-node to establish intranet connection to the frontend via eth0-switch, as well as to the internet via eth1 (if eth1 is present)

echo 'Enter ipaddlastnumber for current node manually.'
echo 'The values of $ipaddlastnumber should be assigned systematically. Each node should has a unqie $ipaddlastnumber value, begins from the positive integer $ipaddlastnumber=21.'
echo 'For example, when installing the first node, set ipaddlastnumber=21. When installing the second node, set ipaddlastnumber=22, etc.'
echo 'The node will reboot after you have entered $ipaddlastnumber.'
echo ' ' 
read -p "Enter ipaddlastnumber for current node: " ipaddlastnumber


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# 1 configure "eth1"
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# Check the identities of the network cards. Select one as the 'eth1' (to guess) and then modify the corresponding /etc/sysconfig/network-scripts/ifcfg-$nc1

nc1=$(lshw -class network | grep -E 'Ethernet interface|logical name' | grep 'logical name' | awk '{print $3}' | awk '!/vir/' |  awk 'NR==1{print}')

echo $nc1 'is chosen as the eth1, external network port. To modify /etc/sysconfig/network-scripts/ifcfg-"$nc1" in the node.'
echo ' '
ls /etc/sysconfig/network-scripts/ifcfg-$nc1

# The following code will replace the ifcfg-$nc1 with the desired content. The original ifcfg-$nc1 will be saved as ifcfg-$nc1.orig.

cp /etc/sysconfig/network-scripts/ifcfg-$nc1 /etc/sysconfig/network-scripts/ifcfg-$nc1.orig

# replacement:
sed -i 's/static/dhcp/g' /etc/sysconfig/network-scripts/ifcfg-$nc1
sed -i 's/BOOTPROTO=static/BOOTPROTO=dhcp/g' /etc/sysconfig/network-scripts/ifcfg-$nc1
sed -i 's/ONBOOT=no/ONBOOT="yes"/g' /etc/sysconfig/network-scripts/ifcfg-$nc1
echo 'NM_CONTROLLED="yes"' >> /etc/sysconfig/network-scripts/ifcfg-$nc1
#sed -i 's/IPV6INIT="yes"/IPV6INIT="no"/g' /etc/sysconfig/network-scripts/ifcfg-$nc1
#sed -i 's/DHCPCLASS=//g' /etc/sysconfig/network-scripts/ifcfg-$nc1
############################################################


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# 2 configure "eth0"
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# Check the identities of the network cards. Select one as the 'eth0' (to guess) and then modify the corresponding /etc/sysconfig/network-scripts/ifcfg-$nc
nc0=$(lshw -class network | grep -E 'Ethernet interface|logical name' | grep 'logical name' | awk '{print $3}' | awk '!/vir/' |  tail -n1)
echo $nc0 'is chosen as the eth0, internal network port. To modify /etc/sysconfig/network-scripts/ifcfg-"$nc".'
ls /etc/sysconfig/network-scripts/ifcfg-$nc0


cp /etc/sysconfig/network-scripts/ifcfg-$nc0 /etc/sysconfig/network-scripts/ifcfg-$nc0.orig

# replacement:
sed -i 's/BOOTPROTO=dhcp/BOOTPROTO=static/g' /etc/sysconfig/network-scripts/ifcfg-$nc0
sed -i 's/dhcp/static/g' /etc/sysconfig/network-scripts/ifcfg-$nc0
sed -i 's/IPV6INIT="yes"/IPV6INIT="no"/g' /etc/sysconfig/network-scripts/ifcfg-$nc0
sed -i 's/DHCPCLASS=//g' /etc/sysconfig/network-scripts/ifcfg-$nc0
sed -i 's/ONBOOT=no/ONBOOT="yes"/g' /etc/sysconfig/network-scripts/ifcfg-$nc0

# append
echo IPADDR=192.168.1.$ipaddlastnumber >> /etc/sysconfig/network-scripts/ifcfg-$nc0
echo 'NETMASK=255.255.0.0' >> /etc/sysconfig/network-scripts/ifcfg-$nc0
echo 'PREFIX=16' >> /etc/sysconfig/network-scripts/ifcfg-$nc0
echo 'DNS1=192.168.1.10' >> /etc/sysconfig/network-scripts/ifcfg-$nc0
echo 'DOMAIN=local' >> /etc/sysconfig/network-scripts/ifcfg-$nc0
echo 'NM_CONTROLLED="yes"' >> /etc/sysconfig/network-scripts/ifcfg-$nc0
############################################################



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# 3 Configure the default gateway (the IP of the switch) and hostname in /etc/sysconfig/network file in the node
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# The following code will replace the /etc/sysconfig/network file with the desired content. The original netowork file will be saved as network.orig

mv /etc/sysconfig/network /etc/sysconfig/network.orig
touch /etc/sysconfig/network
echo 'NETWORKING=yes' >> /etc/sysconfig/network
echo 'HOSTNAME='compute-0-$ipaddlastnumber >> /etc/sysconfig/network
echo 'GATEWAY='192.168.1.10 >> /etc/sysconfig/network
############################################################



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## 4 Create /etc/systemd/system/network-service-restart.sh
echo '#!/bin/bash' > /usr/local/bin/network-service-restart.sh
echo 'service NetworkManager restart'  >> /usr/local/bin/network-service-restart.sh
echo 'service network restart'  >> /usr/local/bin/network-service-restart.sh
chmod 744 /usr/local/bin/network-service-restart.sh


## create /etc/systemd/system/service-network-restart.service
cat << EOF > /etc/systemd/system/service-network-restart.service
[Unit]
After=mysql.service

[Service]
ExecStart=/usr/local/bin/network-service-restart.sh

[Install]
WantedBy=default.target
EOF

# Next, install systemd service unit and enable it so it will be executed at the boot time:
chmod 664 /etc/systemd/system/service-network-restart.service
systemctl daemon-reload
systemctl enable service-network-restart.service

# If you wish to test your script before you reboot run:
systemctl start service-network-restart.service
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reboot