tz/297/aws step functions (#340)

* Add feature for Step Functions.

* AWS function for wrapping the step function

* Added docs and examples for how to run step functions and check on them

* Update package.json

* Updated yarn file

* tz/297/aws-step-functions
* fix linting

---------

api/package.json

@@ -6,6 +6,7 @@
     "@aws-sdk/client-s3": "^3.472.0",
     "@aws-sdk/client-secrets-manager": "^3.478.0",
     "@aws-sdk/client-ses": "^3.470.0",
+    "@aws-sdk/client-sfn": "^3.470.0",
     "@aws-sdk/client-sqs": "^3.470.0",
     "@aws-sdk/client-ssm": "^3.462.0",
     "@aws-sdk/rds-signer": "^3.462.0",

api/src/lib/aws.ts

@@ -6,6 +6,11 @@ import {
   PutObjectCommandInput,
   S3Client,
 } from '@aws-sdk/client-s3'
+import {
+  SFNClient,
+  StartExecutionCommand,
+  StartExecutionCommandOutput
+} from '@aws-sdk/client-sfn';
 import {
   ReceiveMessageCommand,
   SendMessageCommand,
@@ -165,11 +170,51 @@ async function receiveSqsMessage(queueUrl: string) {
   )
 }
 
+/**
+ * Create a step function execution.
+ * AWS docs can be found at the following:
+ * https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/sfn/command/StartExecutionCommand/
+ *
+ * For localstack docs, see https://docs.localstack.cloud/user-guide/aws/stepfunctions/
+ *
+ * @param arn
+ * @param name
+ * @param input
+ * @param traceHeader
+ */
+async function startStepFunctionExecution(
+  arn: string,
+  name?: string,
+  input?: any,
+  traceHeader?: string,
+): Promise<StartExecutionCommandOutput> {
+  let client: SFNClient;
+  const command = new StartExecutionCommand(
+    {
+      stateMachineArn: arn,
+      name,
+      input: input ?? "{}",
+      traceHeader,
+    }
+  );
+  if (process.env.LOCALSTACK_HOSTNAME) {
+    console.log('------------ USING LOCALSTACK FOR SFN ------------')
+    const endpoint = `http://${process.env.LOCALSTACK_HOSTNAME}:${
+      process.env.EDGE_PORT || 4566
+    }`
+    client = new SFNClient({ endpoint, region: process.env.AWS_DEFAULT_REGION })
+  } else {
+    client = new SFNClient()
+  }
+  return await client.send(command)
+}
+
 export default {
   sendPutObjectToS3Bucket,
   sendHeadObjectToS3Bucket,
   getSignedUrl,
   sendSqsMessage,
   receiveSqsMessage,
   getS3Client,
+  startStepFunctionExecution,
 }

localstack/docker-compose.yml

@@ -15,3 +15,5 @@ services:
       - "${LOCALSTACK_VOLUME_DIR:-./volume}:/var/lib/localstack"
       - "/var/run/docker.sock:/var/run/docker.sock"
       - "./entrypoint/init-aws.sh:/etc/localstack/init/ready.d/init-aws.sh"
+      - "../scripts/function.zip:/tmp/function.zip"
+      - "../scripts/function_py.zip:/tmp/function_py.zip"

localstack/entrypoint/init-aws.sh

@@ -14,3 +14,55 @@ done
 
 awslocal s3api create-bucket --bucket cpf-reporter --region us-west-2 --create-bucket-configuration '{"LocationConstraint": "us-west-2"}'
 
+awslocal lambda create-function \
+  --function-name localstack-js-lambda-example \
+  --runtime nodejs16.x \
+  --zip-file fileb:///tmp/function.zip \
+  --handler index.handler \
+  --role arn:aws:iam::000000000000:role/lambda-role
+
+awslocal lambda create-function \
+  --function-name localstack-py-lambda-example \
+  --runtime python3.9 \
+  --zip-file fileb:///tmp/function_py.zip \
+  --handler sample_lambda.lambda_handler \
+  --role arn:aws:iam::000000000000:role/lambda-role
+
+#
+# The js lambdas can be a bit tricky for inputs,
+# so instead we use two python lambdas strung together
+#
+awslocal stepfunctions create-state-machine \
+  --name "run-sample-functions" \
+  --definition '{
+    "Comment": "Invoke Two Lambda Functions",
+    "StartAt": "Lambda1",
+    "States": {
+        "Lambda1": {
+            "Type": "Task",
+            "Resource": "arn:aws:states:::lambda:invoke",
+            "Parameters": {
+                "FunctionName": "localstack-py-lambda-example",
+                "Payload": {
+                    "input.$": "$"
+                }
+            },
+            "OutputPath": "$.Payload",
+            "Next": "InvokeLambda"
+        },
+        "InvokeLambda": {
+            "Type": "Task",
+            "Resource": "arn:aws:states:::lambda:invoke",
+            "Parameters": {
+                "FunctionName": "localstack-py-lambda-example",
+                "Payload": {
+                    "input.$": "$"
+                }
+            },
+            "OutputPath": "$.Payload",
+            "End": true
+        }
+    }
+  }' \
+  --role-arn "arn:aws:iam::000000000000:role/stepfunctions-role"
+

scripts/awsTest.ts

@@ -0,0 +1,23 @@
+import aws from 'api/src/lib/aws'
+
+export default async ({ args }) => {
+  /*
+    Example running:
+      yarn redwood exec awsTest --input '{"var1":"val1"}' --arn arn:aws:states:us-west-2:000000000000:stateMachine:run-sample-functions --name "testing"
+
+    Using the executionArn from above in the next command.
+    The arn should looks something like
+        arn:aws:states:us-west-2:000000000000:execution:run-sample-functions:8110adbe-6807-443f-82ba-6acf9bc527ea
+
+    To check the output, do the following:
+        docker exec -it cpf-reporter-localstack-main /bin/bash
+        awslocal stepfunctions describe-execution --execution-arn [executionArn from above]
+   */
+
+  console.log(':: Executing script with args ::')
+  console.log(`Received following arguments: ${Object.keys(args)}`)
+
+  const result = await aws.startStepFunctionExecution(args.arn, args.name, args.input, '');
+  console.log(result);
+  console.log(result.body);
+};

scripts/sample_lambda.js

@@ -0,0 +1,11 @@
+/**
+ * To build this, zip it using zip scripts/function.zip scripts/sample_lambda.js
+ */
+exports.handler = async (event) => {
+  //console.log("EVENT: " + JSON.stringify(event));
+  const response = {
+    statusCode: 200,
+    body: "Hello from my LocalStack Lambda function!\n" + event.input,
+  };
+  return response;
+};

scripts/sample_lambda.py

@@ -0,0 +1,6 @@
+"""
+ To build this, zip it using zip scripts/function.zip scripts/sample_lambda.py
+"""
+def lambda_handler(event, context):
+    print(event)
+    return {k: f"{v}_sample" for k, v in event["input"].items()}