Configurate and tune an EC2 could be fun. At least once. At some point is good to have the image of the finalized EC2 at hand to make similar instances quicker. Amazon calls images as Amazon Machine Images (AMIs). These hand-made and polished AMIs can be used conveniently for example in Launch configurations. The amount of further configuration is decreased during the autoscaling with hand-made AMIs. Even though AMIs are regional and private by default, it is possible to share those between two accounts. If the AMI is required on the other region, it have to be copied first to that region. Nevertheless, the first step is to create the AMI.
Step 1 – Create the image
Even though it is not necessary a must to stop the instance before the image creation, it is highly recommended. At least the reboot should be allowed during the process. Quite often the image is not working due to the creation process that had not included reboot or stopped instance. After the instance is stopped, just go to Actions and select Create Image (figures 1 & 2).
Figure 1. Stop the instance and go to Actions
Figure 2. Create image
Step 2. – Share the image
The image creation status can be found on Images -> AMIs right after the image creation has been started. Image is actually an EBS snapshot and therefore snapshot creation status can be found on Elastic Block Storage -> Snapshots. After a few minutes the image creation status reaches available status.
Sharing the image, select Modify Image Permissions and add permission to the target AWS account id (figure 3).
Figure 3. Add permissions to the AMI
Step 3. Launch the image on the target account
Log in to the target AWS account and select Launch instance. Choose My Amis -> Shared with me and pick just shared created AMI (figure 4). As a side note, sharing RDS snaphots is a similar & simple task and there are a lot analogues in the RDS-snapshot sharing process between accounts.
Figure 4. Select & Launch the AMI that is Shared with me
-Tero