[FEATURE] Add first version of CLI

[oscarbc96]

Add first version of a CLI

Examples

Help output

$ cfripper --help
Usage: cfripper [OPTIONS] [TEMPLATES]...

  Analyse AWS Cloudformation templates passed by parameter.

Options:
  --version                       Show the version and exit.
  --resolve / --no-resolve        Resolves cloudformation intrinsic functions
                                  [default: False]
  --resolve-parameters FILENAME   JSON/YML file containing key-value pairs
                                  used for resolving CloudFormation files with
                                  templated parameters. For example, {"abc":
                                  "ABC"} will change all occurrences of
                                  {"Ref": "abc"} in the CloudFormation file to
                                  "ABC".
  --format [json|txt]             Output format  [default: txt]
  --output-folder DIRECTORY       If not present, result will be sent to
                                  stdout
  --logging [CRITICAL|FATAL|ERROR|WARN|WARNING|INFO|DEBUG|NOTSET]
                                  Logging level  [default: INFO]
  --help                          Show this message and exit.

Normal execution

$ cfripper /tmp/root.yaml /tmp/root_bypass.json --format txt
Analysing /tmp/root.yaml...
Not adding CrossAccountTrustRule failure in rootRole because no AWS Account ID was found in the config.
Valid: False
IAMRolesOverprivilegedRule: Role 'rootRole' contains an insecure permission '*' in policy 'root'
FullWildcardPrincipalRule: rootRole should not allow wildcards in principals (principal: '*')

Analysing /tmp/root_bypass.json...
Valid: True

Using resolve flag

$ cfripper /tmp/root.yaml /tmp/root_bypass.json --format txt --resolve
Analysing /tmp/root.yaml...
Not adding CrossAccountTrustRule failure in rootRole because no AWS Account ID was found in the config.
Valid: False
IAMRolesOverprivilegedRule: Role 'rootRole' contains an insecure permission '*' in policy 'root'
FullWildcardPrincipalRule: rootRole should not allow wildcards in principals (principal: '*')

Analysing /tmp/root_bypass.json...
Not adding CrossAccountTrustRule failure in rootRole because no AWS Account ID was found in the config.
Valid: False
IAMRolesOverprivilegedRule: Role 'rootRole' contains an insecure permission '*' in policy 'root'

Using json format and output-folder argument

$ cfripper /tmp/root.yaml /tmp/root_bypass.json --format json --resolve --output-folder /tmp
Analysing /tmp/root.yaml...
Not adding CrossAccountTrustRule failure in rootRole because no AWS Account ID was found in the config.
Result saved in /tmp/root.yaml.cfripper.results.json
Analysing /tmp/root_bypass.json...
Not adding CrossAccountTrustRule failure in rootRole because no AWS Account ID was found in the config.
Result saved in /tmp/root_bypass.json.cfripper.results.json

[jsoucheiron]

I'm not completely sure about including click by default, this will increase the payload size if it's deployed as a lambda, we might want to make it optional. How big is click?

[ocrawford555]

Left a couple of comments to review, but other than those this looks good to me, and a good addition to CFRipper! :)

[jsoucheiron]

file is a keyword

[jsoucheiron]

Use a useful text here. The exception itself is logged regardless