Moved to https://github.com/designfultech/watcher-aws

Watcher [Serverless App]

A simple web page monitoring app sending e-mail alerts about changes to a page.

• AWS : API Gateway, Lambda, DynamoDB, CloudWatch, SQS, SES
• SAM + Swagger (OpenAPI)
• NodeJS 8.10
• REST API, Security: API KEY

Prerequisites

• AWS Account
• AWS CLI
• SAM CLI
• Node JS 8.10
• (Optional) jq

Deployment

1. Create S3 bucket for deployment

   BUCKET NAME is where the deployment artefacts are placed

   aws s3api create-bucket --bucket [BUCKET NAME]

2. Upload Swagger (OpenAPI) file

   aws s3 cp swagger.yaml s3://[BUCKET NAME]/

3. Build the project with SAM

   sam build --build-dir ./dist --template sam.yaml

4. Package the project with SAM

   sam package --s3-bucket [BUCKET NAME] --template-file dist/template.yaml --output-template-file dist/packaged.yaml

5. Deploy the project with CloudFormation

   RECIPIENT EMAIL ADDRESS is where the alert emails are sent about webpage content changes

   SENDER EMAIL ADDRESS will show up as the sender for the alert emails

   aws cloudformation deploy --template-file dist/packaged.yaml \
       --stack-name WatcherAppStack \
       --s3-bucket [BUCKET NAME] \
       --capabilities CAPABILITY_NAMED_IAM \
       --parameter-overrides \
           "SwaggerLocation=s3://[BUCKET NAME]/swagger.yaml" \
           "SESRecipient=[RECIPIENT EMAIL ADDRESS]" \
           "SESSender=SENDER EMAIL ADDRESS"

   There are optional parameters you can change

   • EnvironmentParameter=dev|prod sets the environment for deployment
   • SESRegion=eu-west-1|us-east-1|us-west-2 sets the region for sending e-mails with SES

6. Get the output from the deployment

   aws cloudformation describe-stacks --stack-name WatcherAppStack | jq .Stacks[0].Outputs

   This command uses jq to extract the outputs from the JSON reponse.

7. Verify sender and recipient e-mail addresses in the AWS SES console

8. Create an API key for authentication

   aws apigateway create-api-key --enabled --name [API KEY NAME]

9. Add the key to the usage plan

   PLAN ID can be found in the deployment output, look for the object with "OutputKey": "UsagePlanId"

   API KEY ID look for the "id" value in the reponse from creating the API key

   aws apigateway create-usage-plan-key --key-type "API_KEY" --usage-plan-id [PLAN ID] --key-id [API KEY ID]

Remove Deployment

Remove the deployment (deleting stack) if the app is not needed anymore, or if something goes wrong during deployment that needs fixing before trying it again.

aws cloudformation delete-stack --stack-name WatcherAppStack

Test

1. Create a new watcher item

   API ROOT URL can be found in the deployment output, look for the object with "OutputKey": "ApiRootUrl"

   API KEY is the value of the "value" attribute from the response when the API key was created

   curl -X POST [API ROOT URL]/watcher \
       -H "x-api-key:[API KEY]" \
       -H "Content-Type: application/json" \
       -d '{"location": "https://google.com/", "path": "//title/text()"}'

2. List the watcher items

   curl -X GET [API ROOT URL]/watcher \
       -H "x-api-key:[API KEY]"

3. Run a watcher manually to check for changes

   WATCHER ID is the value of the "id" attribute of the watcher from the previous listing

   curl -X GET [API ROOT URL]/watcher/[WATCHER ID]/run \
       -H "x-api-key:[API KEY]"

4. Delete the watcher

   curl -X DELETE [API ROOT URL]/watcher/[WATCHER ID] \
       -H "x-api-key:[API KEY]"

   NOTE: The scheduled timer will run the watcher automatically in every 6 hours if you do not delete it