cfn-show.md

cfn-show

The cfn-show command provides a number of different views of a CloudFormation json templates contents.

The basic command will display all the names of all resources in a given section, defaulting to 'Resources'.

$ cfn-show templates/web-app.json

LocationAppServerELB
AWS::ElasticLoadBalancing::LoadBalancer

LocationAppServerFleet
AWS::AutoScaling::AutoScalingGroup

LocationAppServerFleetLaunchConfig
AWS::AutoScaling::LaunchConfiguration

You can also specify an alternate section to display.

$ cfn-show templates/web-app.json outputs

HTTPSURL
Outputs

If you are unsure of which sections a template contains you can run

$ cfn-show templates/web-app.json sections

Conditions
Mappings
Outputs
Parameters
Resources

Once you've found the section and resource you're interested in you can expand it -

$ cfn-show templates/web-app.json resources IAMRolesStack

{
    "Type": "AWS::CloudFormation::Stack",
    "Properties": {
        "TemplateURL": {
            "Ref": "IAMRolesURL"
        },
        "Parameters": {
            "App": "location",
            "Type": "webapp",
            "Stack": {
                "Ref": "CommonStackName"
            },
            "Env": {
                "Ref": "DeploymentEnvironment"
            }
        }
    }
}

You can alter the format of this display with the 'indent' and 'show name' options:

$ cfn-show templates/web-app.json resources IAMRolesStack -n -i 2

"IAMRolesStack" :  {
  "Type": "AWS::CloudFormation::Stack",
  "Properties": {
    "TemplateURL": {
      "Ref": "IAMRolesURL"
    },
  ... snip ...