Contents
Elastic IP
Using Amazon’s elastic IPs means that when the instance is restarted the IP remaps meaning that you don’t have to change configuration.
When an EC2 instance queries the external DNS name of an Elastic IP, the EC2 DNS server returns the internal IP address of the instance to which the Elastic IP address is currently assigned.
[ec2-user@ip-172-31-13-108 ~]$ host ec2-54-67-44-243.us-west-1.compute.amazonaws.com
ec2-54-67-44-243.us-west-1.compute.amazonaws.com has address 172.31.15.62SSH Config
Adding the instances to the ssh config means that they can then be referenced in the Ansible inventory and all authentication is handled behind the scenes.
Host ec2-boapp
User ec2-user
IdentityFile /home/jmorgan/.ssh/jmorgan_openbet_ca.pem
ProxyCommand ssh -q rosalind nc -q0 ec2-54-67-42-13.us-west-1.compute.amazonaws.com 22Adding an extra volume for Centos
Centos AMI images don’t seem to preserve the volume information on startup. In addition the root volume is limited to 8GB.
I asked about this on Stack Overflow. Currently the way i’m trying to fix it is to mount a second partition to /opt and leave the root as 8GB
The information below is taken from the AWS Guide
[ec2-user ~]$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda 202:0 0 20G 0 disk
├─xvda1 202:1 0 8G 0 part /
└─xvda2 202:2 0 7G 0 part [SWAP]
xvdb 202:16 0 30G 0 disk <----------- needs to be formatted and mountedCheck whether we need to create a file system, data indicates no filesystem
sudo file -s /dev/xvdb
/dev/xvdb: dataCreate ext4 filesystem
[ec2-user ~]$ sudo mkfs -t ext4 device_name[ec2-user ~]$ sudo mkfs -t ext4 /dev/xvdb
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
1966080 inodes, 7864320 blocks
393216 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
240 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000
...[ec2-user ~]$ sudo file -s /dev/xvdb
/dev/xvdb: Linux rev 1.0 ext4 filesystem data (extents) (large files) (huge files)Mount the new filesystem, in this instance its mounted as /opt where the majority of our software is to be installed
sudo mount -t ext4 -o rw /dev/xvdb /opt/[ec2-user@ip-172-31-1-58 ~]$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/xvda1 7.9G 1.1G 6.4G 15% /
tmpfs 15G 0 15G 0% /dev/shm
/dev/xvdb 30G 172M 28G 1% /opt <----- new mount is available