CoreOS Installation

Core OS LiveCD
Boot With Coreos Live CD or USB Drive.
it is login to system automatically .
to Login to root account.
sudo su - root

* SSH private and public key generated on the machine used to connect to the CoreOS server.
Procedure :
ssh-keygen -t rsa -b 2048
Follow the screens and genarate SSH Keys
cat /home/user/.ssh/id_rsa.pub
and copy the ssh pub key

create another file named cloud-config.yaml
with below Template
-------------------------------------
#cloud-config

coreos:
  etcd:
    name: "node001"
    # generate a new token for each unique cluster from https://discovery.etcd.io/new
    discovery: "https://discovery.etcd.io/<token>"
    # multi-region and multi-cloud deployments need to use $public_ipv4
    addr: "$public_ipv4:4001"
    peer-addr: "$private_ipv4:7001"

coreos:
  etcd2:
    # generate a new token for each unique cluster from https://discovery.etcd.io/new?size=3
    discovery: "https://discovery.etcd.io/<token>"
    # multi-region and multi-cloud deployments need to use $public_ipv4
    advertise-client-urls: "http://$public_ipv4:2379"
    initial-advertise-peer-urls: "http://$private_ipv4:2380"
    # listen on both the official ports and the legacy ports
    # legacy ports can be omitted if your application doesn't depend on them
    listen-client-urls: "http://0.0.0.0:2379,http://0.0.0.0:4001"
    listen-peer-urls: "http://$private_ipv4:2380,http://$private_ipv4:7001"
    
coreos:
  fleet:
      public-ip: "$public_ipv4"
      metadata: "region=us-west"
      
coreos:
  flannel:
      etcd_prefix: "/coreos.com/network2"
      
coreos:
  update:
    reboot-strategy: "etcd-lock"
    

coreos:
  units:
    - name: "docker-redis.service"
      command: "start"
      content: |
        [Unit]
        Description=Redis container
        Author=Me
        After=docker.service

        [Service]
        Restart=always
        ExecStart=/usr/bin/docker start -a redis_server
        ExecStop=/usr/bin/docker stop -t 2 redis_server
    
coreos:
  units:
    - name: "docker.service"
      drop-ins:
        - name: "50-insecure-registry.conf"
          content: |
            [Service]
            Environment=DOCKER_OPTS='--insecure-registry="10.0.1.0/24"
            
coreos:
  units:
    - name: "etcd2.service"
      command: "start"
    - name: "fleet.service"
      command: "start"
      
ssh_authorized_keys:
  - "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC0g+ZTxC7weoIJLUafOgrm+h..."

hostname: "coreos1"

users:
  - name: "elroy"
    passwd: "$6$5s2u6/jR$un0AvWnqilcgaNB3Mkxd5yYv6mTlWfOoCYHZmfi3LDKVltj.E8XNKEcwWm..."
    groups:
      - "sudo"
      - "docker"
    ssh-authorized-keys:
      - "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC0g+ZTxC7weoIJLUafOgrm+h..."



write_files:
  - path: "/etc/resolv.conf"
    permissions: "0644"
    owner: "root"
    content: |
      nameserver 8.8.8.8
  - path: "/etc/motd"
    permissions: "0644"
    owner: "root"
    content: |
      Good news, everyone!
  - path: "/tmp/like_this"
    permissions: "0644"
    owner: "root"
    encoding: "gzip"
    content: !!binary |
      H4sIAKgdh1QAAwtITM5WyK1USMqvUCjPLMlQSMssS1VIya9KzVPIySwszS9SyCpNLwYARQFQ5CcAAAA=
  - path: "/tmp/or_like_this"
    permissions: "0644"
    owner: "root"
    encoding: "gzip+base64"
    content: |
      H4sIAKgdh1QAAwtITM5WyK1USMqvUCjPLMlQSMssS1VIya9KzVPIySwszS9SyCpNLwYARQFQ5CcAAAA=
  - path: "/tmp/todolist"
    permissions: "0644"
    owner: "root"
    encoding: "base64"
    content: |
      UGFjayBteSBib3ggd2l0aCBmaXZlIGRvemVuIGxpcXVvciBqdWdz
      
manage_etc_hosts: "localhost"
  
------------------------------------------

Save the file and then execute the install script specifying the new cloud-config.yaml file and the hard drive you want to install coreos on.
* -d – Specifies the destination drive that CoreOS will be installed on
* -C – Specifies the channel we want to grab CoreOS from, stable, or beta
* -c – Specifies the location of the config file (cloud-config.yaml) that we want to use.

coreos-install -d /dev/sda -C stable -c cloud-config.yml


--------------------------
Generating a password hash

If you choose to use a password instead of an SSH key, generating a safe hash is extremely important to the security of your system. Simplified hashes like md5crypt are trivial to crack on modern GPU hardware. Here are a few ways to generate secure hashes:

# On Debian/Ubuntu (via the package "whois")
mkpasswd --method=SHA-512 --rounds=4096

# OpenSSL (note: this will only make md5crypt.  While better than plantext it should not be considered fully secure)
openssl passwd -1

# Python (change password and salt values)
python -c "import crypt, getpass, pwd; print crypt.crypt('password', '\$6\$SALT\$')"

# Perl (change password and salt values)
perl -e 'print crypt("password","\$6\$SALT\$") . "\n"'

users:
  - name: "elroy"
    passwd: "$6$5s2u6/jR$un0AvWnqilcgaNB3Mkxd5yYv6mTlWfOoCYHZmfi3LDKVltj.E8XNKEcwWm..."
    groups:
      - "sudo"
      - "docker"
    ssh-authorized-keys:
      - "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC0g+ZTxC7weoIJLUafOgrm+h..."