https://github.com/portkey-cloud/cfn-yaml
Generate and parse Cloudformation Yaml
https://github.com/portkey-cloud/cfn-yaml
clojure cloudformation
Last synced: 4 months ago
JSON representation
Generate and parse Cloudformation Yaml
- Host: GitHub
- URL: https://github.com/portkey-cloud/cfn-yaml
- Owner: portkey-cloud
- License: epl-2.0
- Created: 2018-12-30T11:48:28.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2021-03-02T19:31:58.000Z (over 5 years ago)
- Last Synced: 2025-11-22T04:06:59.423Z (7 months ago)
- Topics: clojure, cloudformation
- Language: Clojure
- Size: 34.2 KB
- Stars: 3
- Watchers: 2
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# cfn-yaml
[](https://circleci.com/gh/portkey-cloud/cfn-yaml)
[](https://clojars.org/portkey-cloud/cfn-yaml)
Generate (and read) Cloudformation Yaml templates from Clojure data.
Also validates references in the templates.
## Status and motivation
Initial goal was to be able to parse ClouFormation Yaml templates that contain [intrinsic function](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference.html) tags, for example `!Sub 'Hello ${AWS::StackName}'`, into Clojure data. These [tags](https://yaml.org/spec/1.1/#local%20tag/) need support from the parser, for which [snakeyaml](https://bitbucket.org/asomov/snakeyaml/wiki/Documentation#markdown-header-constructors-representers-resolvers) provides support via constructors and representers. This library implements constructors and representers for some short form tags: Sub, Ref, Cidr, Base64, GetAtt, Join, FindInMap.
## Usage
First, add the dependency to `deps.edn`:
```clojure
{:deps {portkey-cloud/cfn-yaml {:git/url "https://github.com/portkey-cloud/cfn-yaml"
:sha "79b3c975a25c14f12c41398863f1cb4a3521c4e7"}}}
```
Then hack in the repl :). The example below uses [aws-api](https://github.com/cognitect-labs/aws-api) for pushing the generated YAML to Cloudformation API, so the repl is started with a `AWS_PROFILE` containing credentials for making API calls to AWS.
```clojure
0% AWS_REGION=eu-west-1 AWS_PROFILE=tiuhti clj -A:aws:rebel
[Rebel readline] Type :repl/help for online help info
user=> (require '[cfn-yaml.core :as cfn])
nil
user=> (require '[cfn-yaml.tags.api :refer :all]) ;; For convenience, i.e. (!Sub "...")
nil
user=> (def tpl (cfn/generate-string
#_=> {:Parameters {:NamePrefix {:Type "String"}}
#_=> :Resources (into {} (for [stage [:dev :test :prod]
#_=> :let [stage-name (name stage)]]
#_=> [stage-name {:Type "AWS::S3::Bucket"
#_=> :Properties {:BucketName (!Sub (str "${NamePrefix}-" stage-name))}}]))}))
#'user/tpl
user=> (println tpl)
Parameters:
NamePrefix:
Type: String
Resources:
dev:
Type: AWS::S3::Bucket
Properties:
BucketName: !Sub '${NamePrefix}-dev'
test:
Type: AWS::S3::Bucket
Properties:
BucketName: !Sub '${NamePrefix}-test'
prod:
Type: AWS::S3::Bucket
Properties:
BucketName: !Sub '${NamePrefix}-prod'
nil
user=> (cfn/parse tpl)
#ordered/map ([:Parameters #ordered/map ([:NamePrefix #ordered/map ([:Type "String"])])]
[:Resources #ordered/map ([:dev #ordered/map ([:Type "AWS::S3::Bucket"]
[:Properties #ordered/map ([:BucketName #cfn_yaml.tags.!Sub{:string "${NamePrefix}-dev", :bindings{}}])])]
[:test #ordered/map ([:Type "AWS::S3::Bucket"]
[:Properties #ordered/map ([:BucketName #cfn_yaml.tags.!Sub{:string "${NamePrefix}-test", :bindings {}}])])]
[:prod #ordered/map ([:Type "AWS::S3::Bucket"]
[:Properties #ordered/map ([:BucketName #cfn_yaml.tags.!Sub{:string "${NamePrefix}-prod", :bindings {}}])])])])
user=> (require '[cognitect.aws.client.api :as aws])
nil
user=> (def cfn-client (aws/client {:api :cloudformation}))
#'user/cfn-client
user=> (aws/invoke cfn-client {:op :CreateStack
#_=> :request {:StackName "cfn-yaml-demo"
#_=> :TemplateBody tpl
#_=> :Parameters [{:ParameterKey "NamePrefix"
#_=> :ParameterValue (str (java.util.UUID/randomUUID))}]}})
{:StackId "arn:aws:cloudformation:eu-west-1:262355063596:stack/cfn-yaml-demo/290de310-0c25-11e9-9e69-0a611b368f3e"}
user=> (def s (aws/invoke cfn-client {:op :DescribeStackResources
#_=> :request {:StackName "cfn-yaml-demo"}}))
#'user/s
user=> (doseq [{:keys [LogicalResourceId PhysicalResourceId]} (:StackResources s)]
#_=> (println LogicalResourceId PhysicalResourceId))
dev 2b5a9713-292c-488a-b4e0-32196a34471b-dev
prod 2b5a9713-292c-488a-b4e0-32196a34471b-prod
test 2b5a9713-292c-488a-b4e0-32196a34471b-test
```
## License
Copyright © 2018-2020 Kimmo Koskinen
Distributed under the Eclipse Public License either version 1.0 or (at
your option) any later version.