Initial setup for DCOS

Configuring all the three nodes with common configurations.

Step 1 : Update the OS with latest patches

>> sudo -i

Note : Make sure you run all the commands with root user.

>> apt-get udpate

Step 2 : Install docker and make sure it is healthy

>> apt-get -y install docker.io

>> ln -sf /usr/bin/docker.io /usr/local/bin/docker

>> docker info

At this point if you come across below error in the output of above command some where

WARNING: No swap limit support

Then please follow troubleshooting case to fix it.

Step 3 : Install and enable NTP

>> apt-get install -y ntp

>> ntptime

>> apt-get install adjtimex -y

>> adjtimex -p

>> timedatectl

Step 4 : Installing required packages

>> apt-get install curl -y

>> apt-get install ipset -y

Step 5 : Disable sudo password prompts

>> cd /etc

>> chmod 755 sudoers

Edit the above file using vim editor and add the below entry in the file

%wheel ALL=(ALL) NOPASSWD: ALL

Step 6 : Configure below environment variable.

>> localectl set-locale LANG=en_US.utf8

Step 7 : Creating below soft links. Just run the below commands.

>> ln -sf /bin/mkdir /usr/local/bin/mkdir

>> ln -sf /bin/ln /usr/local/bin/ln

>> ln -sf /bin/useradd /usr/local/bin/useradd

>> ln -sf /bin/tar /usr/local/bin/tar

The reason we are creating these soft links are because the dcos installation script have references to use these commands and they have been implemented keeping in mind other OS [ but not ubuntu ]

Alright ! If everything looks good, you are good to go for next step !