Feat/execute script enhancements (#281)

* feat: Allowed execute script to work without cloudformation and enhanced it to allow an argument to point to a custom input file

* feat: improved error handling

* feat: update README-EXECUTE.md

* feat: update README-EXECUTE.md

* feat: remove script comment

Author: meathead23

README-EXECUTE.md

@@ -6,7 +6,7 @@ Independently of how you've deployed the state machine, you can execute it in a
 
 You'll find a few sample scripts in the `scripts` folder.
 
-Feel free to customize the `scripts/sample-execution-input.json`, and then run `scripts/execute.sh`.
+Feel free to customize the `scripts/sample-execution-input.json` or add a new json file, and then run `scripts/execute.sh [input json]` by default if input json is not passed then the script will default to `sample-execution-input.json`.
 
 The script will start a state machine execution, wait for the execution to complete (polling), and then show the execution results.
 

scripts/execute.sh

@@ -1,10 +1,19 @@
 #!/bin/bash
 # config
-STACK_NAME=lambda-power-tuning
-INPUT=$(cat scripts/sample-execution-input.json)  # or use a static string
+
+set -euo pipefail
+
+if [[ $# -gt 1 ]]
+then
+    echo "Incorrect Usage: $0 [input json file path]"
+    exit 1
+fi
+
+STACK_NAME=lambda_power_tuning
+INPUT=$(cat "${1:-sample-execution-input.json}")  # or use a static string
 
 # retrieve state machine ARN
-STATE_MACHINE_ARN=$(aws cloudformation describe-stacks --stack-name $STACK_NAME --query 'Stacks[0].Outputs[?OutputKey==`StateMachineARN`].OutputValue' --output text)
+STATE_MACHINE_ARN=$(aws stepfunctions list-state-machines --query "stateMachines[?contains(name,\`${STACK_NAME}\`)]|[0].stateMachineArn" --output text | cat)
 
 # start execution
 EXECUTION_ARN=$(aws stepfunctions start-execution --state-machine-arn $STATE_MACHINE_ARN --input "$INPUT"  --query 'executionArn' --output text)
@@ -30,7 +39,7 @@ do
         echo $STATUS
         echo "Execution output: "
         # retrieve output
-        aws stepfunctions describe-execution --execution-arn $EXECUTION_ARN --query 'output' --output text
+        aws stepfunctions describe-execution --execution-arn $EXECUTION_ARN --query 'output' --output text | cat
         break
     fi
 done