When using Konvoy Image Builder (KIB) to create a base OS image, compliant with DKP, the instructions on how to build and configure the image are included in the file located in images/<builder-type>/<os>-<version>.yaml
:
./konvoy-image build images/<builder-type>/{os}-{version}.yaml
Although there are several parameters specified by default in the packer templates for each provider, it is possible to override the default values. One option is to execute KIB with specific flags to override the values of the source AMI (--source-ami
), AMI region (--ami-regions
), AWS EC2 instance type (--aws-instance-type
), and so on. For a comprehensive list of these flags, please run:
./konvoy-image build --help
Another option is by creating a file with the parameters to be overriden and specify the --overrides
flag as shown below:
./konvoy-image build images/<builder-type>/<os>-<version>.yaml --overrides overrides.yaml
Example 1:
For example, when using the AWS Packer builder to override the above base image with another base image, create an override file and set the source_ami
under the packer key. This overrides the image search and forces the use of the specified source_ami
.
---
packer:
source_ami: "ami-0123456789"
After creating the override file for our source_ami
, we can pass our override file by using the --overrides
flag when building our image:
./konvoy-image build images/ami/centos-7.yaml --overrides override-source-ami.yaml
Example 2:
To abide to security practices, a user could set their own username and password while creating the base OS image and override the default credentials in KIB by creating a file with the following content:
---
packer:
ssh_username: "<USERNAME>"
ssh_password: "<PASSWORD>"
For a complete list of the variables that can be modified for each packer builder, users can refer to: