Params Lookup Locations
Lono supports param files that look like env files as a simple way to define your CloudFormation run-time parameters.
You can define params files in different locations. Lono lookups up each of these locations until it finds a params file.
Depending on how you name your blueprint, templates, and params files, it can greatly simply the configs structure. Some examples will help explain:
1. All Different: blueprint, template, param
Let’s say you had a blueprint that defines a different template and uses a different param. For example, the template could be
jenkins and params could be
large. Then you would need the full 1st form which is fully explicit:
In this case, blueprint, template, and param are all different. So we require a fully explicit command:
lono cfn deploy ec2 --template jenkins --param large lono cfn deploy myserver --blueprint ec2 --template jenkins --param large
2. Only template and param are the same
The 2nd form is when you have the same value for the template and param. For example, the template and params could both be
In this form the template and param file are the same so can slightly simplify the command:
lono cfn deploy ec2 --template jenkins lono cfn deploy myserver --blueprint ec2 --template jenkins
3. All the Same: blueprint, template, param
Let’s say the blueprint, template, and param have the same value of
ec2. This allows you to use the 3rd form.
Thanks to conventions, the deploy command is greatly simplified:
lono cfn deploy ec2 # the stack is called ec2 lono cfn deploy myserver --blueprint ec2 # the stack is called myserver
Project vs Blueprint Configs
Some blueprints contain starter example params. When lono is able to find a project param file, it will use that instead of any blueprint example params. Here’s an example:
blueprints/ec2/config/params/development.txt # ignored entirely configs/ec2/params/development.txt # will be used
The params in
blueprints only get used if you have not created one in
configs. So the blueprint params will get ignored.
If there are no user-defined param
configs, lono looks through the blueprint’s param config folder with the same lookup Locations as detailed above.
Pro tip: Use the <- and -> arrow keys to move back and forward.