Level Up Your Serverless Game

This workshop consists of multiple levels of increasing difficulty. The basic track of this course uses the AWS Web Console. However, as soon as you're done with that track, you can alternatively use the AWS CLI version 2 or Terraform. You can switch to one of these technologies at any stage in the course. All serverless functions in this course are written in Node.js. If you stay on the basic track, you will only need to have the Node.js runtime and npm installed on your machine. If you want to switch to the CLI or to Terraform, you need to follow the optional installation instructions below.

The commands are geared towards Unix systems. If you're using Windows, you might need to adapt some of them. A more convenient solution is to use WSL or Git BASH.

Preparation

At the start of the course, take care of the following tasks:

Ensure Node.js and npm are installed

Ensure that you have Node.js runtime version 18.x or newer installed on your machine. If you need to install it, follow the instructions on the Node.js site. Furthermore, you will also need the npm CLI. After the Node.js installation, type npm in a shell, to check that it is available.

In case you cannot or do not want to install Node.js and npm, you can also run the commands via a container. For example, using Docker:

docker run --rm -t -v "${PWD}:/src" -w '/src' docker.io/node:alpine npm install

Clone this repo

Next, you will need this repo on your own machine. Run git clone https://github.com/bespinian/serverless-workshop.git to clone this repo with all its steps.

Test your AWS login

Finally, you will of course also require access to AWS. You have received an AWS Account ID, an IAM user name and a password from the trainers. Navigate to https://console.aws.amazon.com/, choose "IAM user", and enter the Account ID and then your credentials. This logs you into the console. From there you should be able to reach the service Lambda.

Level 0 - This is easy!

In this level, you will learn how to create a first simple function in AWS Lambda. You will also learn how to pass configuration parameters into a function using environment variables. Furthermore, you will see that AWS has a very strict, deny-by-default permission scheme.

Steps

Work through the following steps:

1. Go to the AWS Lambda GUI
2. Choose Europe (Frankfurt) eu-central-1 as the region in the top-right corner. All resources you create should be created in that region.
3. Click on Create function
4. Choose my-function-AWSUSER as the function name, replacing AWSUSER with your user name
5. Choose Node.js 18.x as the runtime
6. Open the section Change default execution role and note that the UI automatically creates an execution role behind the scenes, granting the function certain privileges
7. Click Create function
8. Copy the code from level-0/function/index.mjs and paste it into the code editor field
9. In the Configuration tab under Environment variables, set a variable called NAME to the name of a person you like
10. In the Test tab, press the Test button and create a test event called test
11. Press the Test button again to run the test
12. Observe the test output

Add an HTTP Trigger

Lambda functions support various Triggers. Some of the most commonly used ones are:

• HTTP trigger using the API Gateway
• Message queue triggers from Amazon MQ or SQS
• S3 events, such as object creation or deletion events in a bucket
• Apache Kafka events

Work through the following steps to expose your function on the Internet via the API Gateway.

1. In the Functional overview at the top, click Add trigger
2. Select API Gateway
3. For API, select Create a new API
4. Select HTTP API as the API Type
5. Select Open, in Security
6. Click Add
7. Click on the created API and visit the Integrations tab
8. Click the ANY integration and hit the Manage integration button
9. Click Edit and expand the Advanced settings. In there, choose the "Payload format version" 2.0 and hit the Save button
10. You can now close this tab to go back to your function. Changing the integration format was necessary because our function returns the newer and simpler version 2.0 format.
11. You should now see your newly created Trigger and the URL to access it. Click the link to see the response in your browser.

Already done? Try some bonus steps!

Try it with the AWS CLI!

Installation

For the optional CLI steps, you need to install the AWS CLI on your machine. Follow the AWS CLI installation instructions and choose the installation method best suited for your operating system.

Authentication

To authenticate your CLI, you first need to create an access key by performing the following steps:

1. Log in to the AWS Console with your credentials

2. Click on your name in the top right of the screen

3. Click My Security Credentials in the dropdown

4. Click Create Access Key under Access keys for CLI, SDK, & API access

   Then, you need to configure your CLI with access key ID and the secret access key.

5. Type aws configure in your terminal

6. Copy your access key ID and the secret access key from the web console and paste them at the prompts

7. Choose eu-central-1 as the default region name

8. Test the connection by typing aws sts get-caller-identity in your terminal. You should see some basic information about your user.

Steps

1. Set the AWSUSER environment variable.

   export AWSUSER=<your AWS user name>

2. Create an execution role which will allow Lambda functions to access AWS resources:

   aws iam create-role --role-name "lambda-exec-cli-${AWSUSER}" --assume-role-policy-document '{"Version": "2012-10-17","Statement": [{ "Effect": "Allow", "Principal": { "Service": "lambda.amazonaws.com" }, "Action": "sts:AssumeRole" }] }'

3. Grant certain permissions to your newly created role. The managed policy AWSLambdaBasicExecutionRole has the permissions needed to write logs to CloudWatch:

   aws iam attach-role-policy --role-name "lambda-exec-cli-${AWSUSER}" --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

4. Create a deployment package for your function:

   zip -j function.zip level-0/function/index.mjs

5. Find out your Account ID by clicking your user name in the top-right corner. Then set it as a variable in your shell.

   export ACCOUNT_ID=<your account ID>

6. Create the function:

    aws lambda create-function --function-name "my-function-cli-${AWSUSER}" --zip-file fileb://function.zip --handler index.handler --runtime nodejs18.x --role "arn:aws:iam::${ACCOUNT_ID}:role/lambda-exec-cli-${AWSUSER}"

7. Set the NAME environment variable to your user name:

   aws lambda update-function-configuration --function-name "my-function-cli-${AWSUSER}" --environment "Variables={NAME='${AWSUSER}'}"

8. Invoke the function:

   aws lambda invoke --function-name "my-function-cli-${AWSUSER}" output.json --log-type Tail

9. Invoke the function and decode the logs:

   aws lambda invoke --function-name "my-function-cli-${AWSUSER}" output.json --log-type Tail --query 'LogResult' --output text |  base64 -d

10. Create an API on the API gateway

    aws apigatewayv2 create-api --name "my-api-gw-cli-${AWSUSER}" --protocol-type HTTP

11. Set the variable API_ID to the ID that was returned by the command above:

    export API_ID=<the API ID>

12. Create an integration on the API gateway pointing to your Lambda function:

    aws apigatewayv2 create-integration --api-id "$API_ID" --integration-type AWS_PROXY --integration-uri "arn:aws:lambda:eu-central-1:${ACCOUNT_ID}:function:my-function-cli-${AWSUSER}" --payload-format-version 2.0

13. Set the INTEGRATION_ID variable to the value of IntegrationId from the response:

    export INTEGRATION_ID=<the integration id>

14. Create a route pointing to your integration:

    aws apigatewayv2 create-route --api-id "$API_ID" --route-key "ANY /my-function" --target "integrations/${INTEGRATION_ID}" --authorization-type NONE --no-api-key-required

15. Create a stage that deploys the configuration:

    aws apigatewayv2 create-stage --api-id "$API_ID" --auto-deploy --stage-name default

16. Allow the API gateway to access the lambda function:

    aws lambda add-permission --function-name "my-function-cli-${AWSUSER}" --statement-id apigateway-get --action lambda:InvokeFunction --principal apigateway.amazonaws.com --source-arn "arn:aws:execute-api:eu-central-1:${ACCOUNT_ID}:${API_ID}/*/*/my-function"

Still bored? Then try it with Terraform!

Install Terraform

For the optional Terraform steps, you need to install Terraform on your machine. Follow the Terraform installation instructions and choose the installation method best suited for your operating system.

Authentication

To authenticate Terraform, you first need to create an access key by performing the following steps:

1. Log in to the AWS Console with your credentials

2. Click on your name in the top right of the screen

3. Click My Security Credentials in the dropdown

4. Click Create Access Key under Access keys for CLI, SDK, & API access

   Then, you need to configure your machine with access key ID and the secret access key.

5. Type aws configure in your terminal

6. Copy your access key ID and the secret access key from the web console and paste them at the prompts

7. Choose eu-central-1 as the default region name

8. Test the connection by typing aws sts get-caller-identity in your terminal. You should see some basic information about your user.

Steps

1. Copy the Terraform module and the function code to a separate working directory

   mkdir my-tf-module
   cp level-0/advanced/terraform/* my-tf-module
   cp -r level-0/function my-tf-module

2. Navigate to the Terraform module in your work directory

   pushd my-tf-module

3. Initialize the Terraform module

   terraform init

4. Set your AWS user name as an environment variable for Terraform

   export TF_VAR_aws_user=<your AWS user name>

5. Apply the Terraform module

   terraform apply

6. Invoke the function via the AWS CLI

   aws lambda invoke --function-name "$(terraform output -raw function_name)" output.json

7. Invoke the function via HTTP. Access the invoke_url that's returned by terraform apply either through your browser or through curl:

   curl <invoke_url>

8. Navigate back to the workshop repo

   popd

Level 1 - Loggin' it!

To reach level 1, you'll need to learn about the following topics:

• Logging
• Event parameters
• Permissions

Steps

1. In the Lambda GUI of your function, copy the code from level-1/function/index.mjs and paste it over the existing code in the editor field

2. In the Test tab, press the Test button and create a test event called bob

3. Paste the following JSON object to the editor field

   {
     "name": "Bob"
   }

4. Press the Test button again to run the test

5. Navigate to the tab Monitor

6. Click View logs in CloudWatch

7. Look for a recent log stream and open it

8. Check for lines looking like this

   2021-09-10T12:26:33.779Z c70ee5e7-4295-4408-a713-9f3ceaaa53e3 INFO Bob invoked me
   2021-09-10T12:26:33.779Z c70ee5e7-4295-4408-a713-9f3ceaaa53e3 ERROR Oh noes!

9. Navigate back to your function in the Lambda console and switch to the tab Configuration and click on the category Permissions.

10. Observe the logging permissions which were assigned to your function automatically.

Already done? Try some bonus steps!

Try it with the AWS CLI!

1. Make sure the AWSUSER and ACCOUNT_ID environment variables are still set.

   export AWSUSER=<your AWS user name>
   export ACCOUNT_ID=<your account ID>

2. Create a deployment package for your new function:

   zip -j function.zip level-1/function/index.mjs

3. Update the function with the new code:

   aws lambda update-function-code --function-name "my-function-cli-${AWSUSER}" --zip-file fileb://function.zip

4. Invoke the function with a test event:

   aws lambda invoke --function-name "my-function-cli-${AWSUSER}" --cli-binary-format raw-in-base64-out --payload '{ "name": "Bob" }' output.json --log-type Tail

5. Find the latest log stream for your function in CloudWatch:

   aws logs describe-log-streams --log-group-name "/aws/lambda/my-function-cli-${AWSUSER}"

6. Inspect the log events of the log stream. You might have to escape some characters in the value passed in --log-stream-name e.g. $LATEST should be \$LATEST

   aws logs get-log-events --log-group-name "/aws/lambda/my-function-cli-${AWSUSER}" --log-stream-name='<name of latest log stream>'

Still bored? Then try it with Terraform!

1. Make sure your user variable is still set

   export TF_VAR_aws_user=<your AWS user name>

2. Navigate to the Terraform module

   cp -r level-1/function my-tf-module

3. Navigate to your work directory

   pushd my-tf-module

4. Apply the Terraform module again

   terraform apply

5. Invoke the function with a test event:

   aws lambda invoke --function-name "my-function-tf-${TF_VAR_aws_user}" --cli-binary-format raw-in-base64-out --payload '{ "name": "Bob" }' output.json --log-type Tail

6. Find the latest log stream for your function in CloudWatch:

   aws logs describe-log-streams --log-group-name "/aws/lambda/my-function-tf-${TF_VAR_aws_user}"

7. Inspect the log events of the log stream:

   aws logs get-log-events --log-group-name "/aws/lambda/my-function-tf-${TF_VAR_aws_user}" --log-stream-name='<name of latest log stream>'

8. Navigate back to the workshop repo

   popd

Level 2 - Tracin' it!

To reach level 2, you will learn about tracing in your function using AWS X-Ray. Additionally, we will use a DynamoDB table, and trace calls from the function to the table.

We modify the function to read a joke from a joke table and change the function parameters to receive a jokeID parameter by which it reads from the database.

Steps

1. From your terminal, cd into the level-2/function directory of this repo

2. Run npm install

3. Create a zip file from the folder level-2/function

   zip -r function.zip .

4. Upload the zip file to the function by using the Upload from button

5. In the Configuration tab, click Permissions and then click the link to the execution role

6. Click the Add permissions button, select Attach policies and add the "AmazonDynamoDBReadOnlyAccess" and the "AWSXRayDaemonWriteAccess" permissions to grant your function access to DynamoDB and the X-Ray service

7. In the Configuration tab of the lambda function, select the Monitoring and operations tools, click edit and enable Active tracing in the AWS X-Ray section

8. On the function's Test tab, create a test event with the following payload { "jokeID": "1" } and click the Test button. You should see the joke loaded from the database in the response

9. On the Monitor tab, select the Traces menu option and inspect the service map as well as the individual traces. Click on one of the traces to get familiar of what info you have available, such as how long the request to query the DynamoDB took.

10. To call your function via HTTP, you must now provide a payload (you can find the gateway API URL in the Configuration tab under Triggers):

    curl -v -X POST <api-gateway-url> --data '{"jokeID":"1"}'

Already done? Try some bonus steps!

Try it with the AWS CLI!

1. Make sure the AWSUSER and ACCOUNT_ID environment variables are still set.

   export AWSUSER=<your AWS user name>
   export ACCOUNT_ID=<your account ID>

2. Attach a policy for X-Ray access to your role

   aws iam attach-role-policy --role-name "lambda-exec-cli-${AWSUSER}" --policy-arn arn:aws:iam::aws:policy/AWSXrayWriteOnlyAccess

3. Create a policy for access to the "jokes" table in DynamoDB

   aws iam create-policy --policy-name "read-jokes-db-table-cli-${AWSUSER}" --policy-document '{ "Version": "2012-10-17", "Statement": [{ "Sid": "ReadWriteTable", "Effect": "Allow", "Action": [ "dynamodb:BatchGetItem", "dynamodb:GetItem", "dynamodb:Query", "dynamodb:Scan" ], "Resource": "arn:aws:dynamodb:eu-central-1:'${ACCOUNT_ID}':table/jokes" }]}'

4. Attach the policy to your role

   aws iam attach-role-policy --role-name "lambda-exec-cli-${AWSUSER}" --policy-arn "arn:aws:iam::${ACCOUNT_ID}:policy/read-jokes-db-table-cli-${AWSUSER}"

5. Create a deployment package for your new function:

   pushd level-2/function
   npm install
   zip -r function.zip ./*
   popd

6. Update the function with the new code:

   aws lambda update-function-code --function-name "my-function-cli-${AWSUSER}" --zip-file fileb://level-2/function/function.zip

7. Switch on X-Ray tracing for your function

   aws lambda update-function-configuration --function-name "my-function-cli-${AWSUSER}" --tracing-config "Mode=Active"

8. Invoke the function with a test event:

   aws lambda invoke --function-name "my-function-cli-${AWSUSER}" output.json --cli-binary-format raw-in-base64-out --payload '{ "jokeID": "1" }' --log-type Tail --query 'LogResult' --output text |  base64 -d

9. Inspect the traces that have been created during the last 20 minutes:

   aws xray get-service-graph --start-time $(($(date +"%s") -1200)) --end-time $(date +"%s")

Still bored? Then try it with Terraform!

1. Make sure your work directory and user variables are still set

   export TF_VAR_aws_user=<your AWS user name>

2. Copy the new function code and the updated Terraform resources to your work directory

   cp level-2/advanced/terraform/* my-tf-module
   cp -r level-2/function my-tf-module

3. Install the functions dependencies

   pushd my-tf-module/function
   npm install
   popd

4. Navigate to your Terraform module

   pushd my-tf-module

5. Apply the Terraform module again

   terraform apply

6. Switch on X-Ray tracing for your function

   aws lambda update-function-configuration --function-name "my-function-tf-${TF_VAR_aws_user}" --tracing-config "Mode=Active"

7. Invoke the function with a test event:

   aws lambda invoke --function-name "my-function-tf-${TF_VAR_aws_user}" output.json --cli-binary-format raw-in-base64-out --payload '{ "jokeID": "1" }' --log-type Tail --query 'LogResult' --output text |  base64 -d

8. Inspect the traces that have been created during the last 20 minutes:

   aws xray get-service-graph --start-time $(($(date +"%s") -1200)) --end-time $(date +"%s")

9. Navigate back to the workshop repo

   popd

Level 3 - Timin' it!

To reach this level, we'll make sure our function terminates in an orderly fashion within the timeout limit it is configured with. This means, aborting IO operations or long-running calculations when the function time runs out, or at least return to your program flow to handle the return values. The AWS Lambda frameworks allow us to poll how much time is still left in a function call, which simplifies this.

Before you deploy the improved function to lambda, inspect the provided code in level-3/function. You will notice the following points:

• The usage of context.getRemainingTimeInMillis() to receive from Lambda how much time is left in our function
• An additional grace period, we retain for our function in TIMEOUT_GRACE_PERIOD_IN_MILLIS
• That we trigger a promise, that rejects when the remaining time is below the grace period.

Note!

Some AWS resources support the usage of an AbortController to terminate those actions. When doing IO operations using resources that do not support it or doing long-running computations, make sure you set timeouts or implement a timeout check yourself.

Steps

1. Inspect the provided code as described above
2. Click on Functions in the left navigation
3. Choose the function my-function-AWSUSER, which you created in level 0
4. In the Configuration tab of the function, select the General configuration menu and set the timeout to 1 second
5. Note that now only <20ms will be available for the DynamoDB query because our grace period is set to 980ms
6. Run npm install in the function folder
7. Create a zip file from the function folder and upload it to the function
8. On the functions Test tab, create a test event with the following payload { "jokeID": "1" } and click the Test button. You should see the function returning successfully, but with a message, that it reached the timeout.
9. Set the timeout to 2 seconds and try again. This time, the function should be able to read the joke from the database and return it.

Already done? Try some bonus steps!

Try it with the AWS CLI!

1. Make sure the AWSUSER and ACCOUNT_ID environment variables are still set.

   export AWSUSER=<your AWS user name>
   export ACCOUNT_ID=<your account ID>

2. Create a deployment package for your new function:

   pushd level-3/function
   npm install
   zip -r function.zip ./*
   popd

3. Update the function with the new code:

   aws lambda update-function-code --function-name "my-function-cli-${AWSUSER}" --zip-file fileb://level-3/function/function.zip

4. Update the function's timeout setting to 1 second:

   aws lambda update-function-configuration --function-name "my-function-cli-${AWSUSER}" --timeout 1

5. Invoke the function with a test event:

   aws lambda invoke --function-name "my-function-cli-${AWSUSER}" output.json --cli-binary-format raw-in-base64-out --payload '{ "jokeID": "1" }' --log-type Tail --query 'LogResult' --output text |  base64 -d

6. Note that the function succeeds, but in the output tells you, that it ran into a timeout.

7. Update the function's timeout setting to 2 seconds:

   aws lambda update-function-configuration --function-name "my-function-cli-${AWSUSER}" --timeout 2

8. Invoke the function again with a test event:

   aws lambda invoke --function-name "my-function-cli-${AWSUSER}" output.json --cli-binary-format raw-in-base64-out --payload '{ "jokeID": "1" }' --log-type Tail --query 'LogResult' --output text |  base64 -d

9. Note that the function succeeds and returns the joke.

Still bored? Then try it with Terraform!

1. Make sure your work directory and user variables are still set

   export TF_VAR_aws_user=<your AWS user name>

2. Copy the Terraform module and the function code from level 3

   cp -r level-3/advanced/terraform my-tf-module
   cp -r level-3/function my-tf-module

3. Install the functions dependencies

   pushd my-tf-module/function
   npm install
   popd

4. Navigate to your Terraform module

   pushd my-tf-module

5. Apply the Terraform module again

   terraform apply

6. Invoke the function with a test event:

   aws lambda invoke --function-name "my-function-tf-${TF_VAR_aws_user}" output.json --cli-binary-format raw-in-base64-out --payload '{ "jokeID": "1" }' --log-type Tail --query 'LogResult' --output text |  base64 -d

   Note that the function returns, but the response contains an error message because it ran into a timeout.

7. Change the timeout setting of the function in the terraform module in your working directory

8. Apply the Terraform module again

   terraform apply

9. Invoke the function with another test event:

   aws lambda invoke --function-name "my-function-tf-${TF_VAR_aws_user}" output.json --cli-binary-format raw-in-base64-out --payload '{ "jokeID": "1" }' --log-type Tail --query 'LogResult' --output text |  base64 -d

   Note that the function returns successfully, and the response contains the joke loaded from the database.

10. Navigate back to the workshop repo

    popd

Level 4 - Optimized Cold Starts!

To reach level 4, you will need to reduce the cold start time of your function. Warmers are usually not recommended, but you can try moving initialization code outside your handler.

Steps

1. Go to the AWS Lambda UI

2. Click on Functions in the left navigation

3. Choose the function my-function-AWSUSER, which you updated in level 3

4. Run npm install in the folder level-4/function

5. Create a zip file from the folder level-4/function and upload it to the function

6. Press the Test button and create a test event called joke

7. Paste the following JSON object to the editor field

   {
     "jokeID": "1"
   }

8. Press the Test button again to run the test

9. Observe the test output

Already done? Try some bonus steps!

Try it with the AWS CLI!

1. Make sure the AWSUSER and ACCOUNT_ID environment variables are still set.

   export AWSUSER=<your AWS user name>
   export ACCOUNT_ID=<your account ID>

2. Create a deployment package for your new function:

   pushd level-4/function
   npm install
   zip -r function.zip ./*
   popd

3. Update the function with the new code:

   aws lambda update-function-code --function-name "my-function-cli-${AWSUSER}" --zip-file fileb://level-4/function/function.zip

4. Invoke the function with a test event:

   aws lambda invoke --function-name "my-function-cli-${AWSUSER}" --cli-binary-format raw-in-base64-out --payload '{ "jokeID": "1" }' output.json --log-type Tail

Still bored? Then try it with Terraform!

1. Make sure your user variable is still set

   export TF_VAR_aws_user=<your AWS user name>

2. Copy the updated function code to your working directory

   cp -r level-4/function my-tf-module

3. Install the functions dependencies

   pushd my-tf-module/function
   npm install
   popd

4. Navigate to your Terraform module

   pushd my-tf-module

5. Apply the Terraform module again

   terraform apply

6. Invoke the function with a test event:

   aws lambda invoke --function-name "my-function-tf-${TF_VAR_aws_user}" --cli-binary-format raw-in-base64-out --payload '{ "jokeID": "1" }' output.json --log-type Tail

7. Navigate back to the workshop repo

   popd

Level 5 - Decouplin' it!

To reach level 5, you'll need to learn how to decouple multiple functions asynchronously via a message queue.

Steps

1. Navigate to the level 5 code and install the dependencies:

   cd level-5/function
   npm install

2. Package your function

   zip -r function.zip ./*

3. In the Lambda GUI, create a new function called sender-AWSUSER (replace "AWSUSER" with your user name) and leave all the defaults

4. Create another function called recipient-AWSUSER (replace "AWSUSER" with your user name) and leave all the defaults

5. Upload function.zip to both functions and inspect the file. It defines and exports two different handlers. The first one sends an event to an SQS queue and the second one receives it.

6. Scroll down to Runtime settings and change the "Handler" to index.senderHandler for the sender function and to index.recipientHandler for the recipient function. For Node.js, the "index" part refers to the file name and the "handler" part to the name of the export. So, we can have multiple functions in the same source code.

7. Head over to the SQS GUI and create a new queue called messages-AWSUSER replacing "AWSUSER" with your user name and leave all the defaults. Then copy the URL of your newly created queue to the clipboard. The URL can be found in the "Details" of the queue.

8. Set the SQS_QUEUE_URL environment variable to the name of the queue you have just created for the sender function

9. Give the sender function the permission to send messages to the queue by clicking its role name in the "Configuration" tab under "Permissions". Then attach the policy called AmazonSQSFullAccess.

10. Give the recipient function the permission to read messages from the queue by clicking its role name in the "Configuration" tab under "Permissions". Then attach the policy called AWSLambdaSQSQueueExecutionRole.

11. Go to the recipient's GUI and add a trigger by clicking the "Add trigger" button. Then choose "SQS" and choose your newly created queue.

12. Trigger your sender function with a test event

13. Head over to CloudWatch to examine the logs of the sender function. It has dispatched a message to the message queue.

14. Examine the logs of the recipient function. It has been asynchronously triggered by the sender function via the message queue.

Already done? Try some bonus steps!

Try it with the AWS CLI!

1. Make sure the AWSUSER and ACCOUNT_ID environment variables are still set.

   export AWSUSER=<your AWS user name>

2. Create a deployment package for your new functions:

   cd level-5/function
   npm install
   zip -r function.zip ./*

3. Create two new roles:

   aws iam create-role --role-name "sender-exec-cli-${AWSUSER}" --assume-role-policy-document '{"Version": "2012-10-17","Statement": [{ "Effect": "Allow", "Principal": { "Service": "lambda.amazonaws.com" }, "Action": "sts:AssumeRole" }] }'
   aws iam create-role --role-name "recipient-exec-cli-${AWSUSER}" --assume-role-policy-document '{"Version": "2012-10-17","Statement": [{ "Effect": "Allow", "Principal": { "Service": "lambda.amazonaws.com" }, "Action": "sts:AssumeRole" }] }'
   

4. Create two new functions:

   export SENDER_ROLE_ARN=$(aws iam get-role --role-name "sender-exec-cli-${AWSUSER}" --query Role.Arn --output text)
   aws lambda create-function --function-name "sender-cli-${AWSUSER}" --zip-file fileb://function.zip --handler index.senderHandler --runtime nodejs18.x --role "$SENDER_ROLE_ARN"
   export RECIPIENT_ROLE_ARN=$(aws iam get-role --role-name "recipient-exec-cli-${AWSUSER}" --query Role.Arn --output text)
   aws lambda create-function --function-name "recipient-cli-${AWSUSER}" --zip-file fileb://function.zip --handler index.recipientHandler --runtime nodejs18.x --role "$RECIPIENT_ROLE_ARN"

5. Create a new message queue

   aws sqs create-queue --queue-name "messages-cli-${AWSUSER}"

6. Set the SQS_QUEUE_URL environment variable of the sender function to the queue's URL:

   export SQS_QUEUE_URL=$(aws sqs get-queue-url --queue-name "messages-cli-${AWSUSER}" --query QueueUrl --output text)
   aws lambda update-function-configuration --function-name "sender-cli-${AWSUSER}" --environment "Variables={SQS_QUEUE_URL='$SQS_QUEUE_URL'}"

7. Give your sender function the permission to log and to post messages to the queue:

   aws iam attach-role-policy --role-name "sender-exec-cli-${AWSUSER}" --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
   aws iam attach-role-policy --role-name "sender-exec-cli-${AWSUSER}" --policy-arn arn:aws:iam::aws:policy/AmazonSQSFullAccess

8. Give your recipient function the permission to log and read messages from the queue:

   aws iam attach-role-policy --role-name "recipient-exec-cli-${AWSUSER}" --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
   aws iam attach-role-policy --role-name "recipient-exec-cli-${AWSUSER}" --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaSQSQueueExecutionRole

9. Set the SQS queue as a trigger for the recipient function:

   export SQS_QUEUE_ARN=$(aws sqs get-queue-attributes --queue-url "$SQS_QUEUE_URL" --attribute-names QueueArn --query Attributes.QueueArn --output text)
   aws lambda create-event-source-mapping --function-name "recipient-cli-${AWSUSER}" --event-source-arn "$SQS_QUEUE_ARN"

10. Invoke the sender function:

    aws lambda invoke --function-name "sender-cli-${AWSUSER}" output.json --log-type Tail

11. Check out the logs of the sender function to see that the message has been sent:

    aws logs tail "/aws/lambda/sender-cli-${AWSUSER}"

12. Check out the logs of the recipient function to see that it has been triggered, and the message has been received:

    aws logs tail "/aws/lambda/recipient-cli-${AWSUSER}"

Still bored? Then try it with Terraform!

1. Make sure your user variable is still set

   export TF_VAR_aws_user=<your AWS user name>

2. Copy the updated function code to your working directory

   cp -r level-5/advanced/terraform/* my-tf-module
   cp -r level-5/function my-tf-module

3. Install the functions dependencies

   pushd my-tf-module/function
   npm install
   popd

4. Navigate to your Terraform module

   pushd my-tf-module

5. Apply the Terraform module again

   terraform apply

6. Invoke the sender function with a test event:

   aws lambda invoke --function-name "sender-tf-${TF_VAR_aws_user}" --cli-binary-format raw-in-base64-out output.json --log-type Tail

7. Check out the logs of the sender function to see that the message has been sent:

   aws logs tail "/aws/lambda/sender-tf-${TF_VAR_aws_user}"

8. Check out the logs of the recipient function to see that it has been triggered, and the message has been received:

   aws logs tail "/aws/lambda/recipient-tf-${TF_VAR_aws_user}"

9. Navigate back to the workshop repo

   popd

Level 6 - Infra as Code

Infrastructure as code allows us to manage the deployments of our functions and other cloud resources in a much more repeatable and testable way, bringing us to the next level.

To deploy the function from level-4, and it's required resources, follow the steps below. You can also use this to deploy it to your own AWS account with very few commands.

Note!

If you have done some extra work and already deployed the previous levels with Terraform, you may skip this level, as it redeploys the code from level 4.

Prerequisites

For this step, need Terraform installed on your machine. Follow the Terraform installation instructions and choose the installation method best suited for your operating system.

Furthermore, you need to have valid credentials for your AWS user set up in your terminal. You can test that by running the aws sts get-caller-identity command. You should see some basic information about your user. If that doesn't work, go back to the first "Already done? Try some bonus steps!" section in Level 0. There, in "Try it with the AWS CLI!", follow the "Installation" and "Authentication" instructions.

Steps

1. Copy the Terraform module and the function code to a separate working directory

   mkdir my-tf-module
   cp level-6/advanced/terraform/* my-tf-module
   cp -r level-6/function my-tf-module

2. Navigate to the Terraform module in your work directory

   pushd my-tf-module

3. Initialize the Terraform module

   terraform -chdir=my-tf-module init

4. Set your AWS user name as an environment variable for Terraform

   export TF_VAR_aws_user=<your AWS user name>

5. Install the functions dependencies

   cd my-tf-module/function
   npm install
   cd ../..

6. Navigate to your Terraform module

   pushd my-tf-module

7. Apply the Terraform module

   terraform -chdir=my-tf-module apply

8. Invoke the function with a test event:

   aws lambda invoke --function-name "my-function-tf-${TF_VAR_aws_user}" --cli-binary-format raw-in-base64-out --payload '{ "jokeID": "1" }' output.json --log-type Tail

Level 7 - Testing ... duh!

To reach level 7 you need to know how to

• Unit test your functions
• Run your functions locally to make debugging easier

Steps

1. Navigate to the unit test example and install the dependencies:

   pushd level-7/unit-tests
   npm install

2. Inspect the example function, the service mocks and the tests:

   cat index.mjs
   cat index.test.js

3. Run the tests for the example function:

   npm test
   popd

4. Navigate to the local execution example and install the dependencies

   pushd level-7/api-to-serverless
   npm install

5. Inspect the express API and the function code

   cat api.mjs
   cat index.mjs

6. Run the example locally as an express API:

   npm start

7. Make a request to the API in a new terminal:

   curl -X GET http://localhost:3000 -H 'Content-Type:application/json' -d '{ "name":"Bob" }'

8. Package your function

   zip -r function.zip ./*

9. Deploy your function using the UI, the CLI or Terraform and invoke it with a test event of the following form:

   {
     "name": "Bob"
   }

Level 8 - Lockdown!

When you understand that functions can be assigned just the set of privileges that they need, you have reached level 8. To do so, you will observe an example of a function which is trying to write to the "jokes" table, but does not have permission to do so.

Steps

1. Go to the AWS Lambda UI

2. Click on Functions in the left navigation

3. Choose the function my-function-AWSUSER, which you updated in level 4

4. Run npm install in the folder level-8/function

5. Create a zip file from the folder level-8/function and upload it to the function

6. Press the Test button and create a test event called joke

7. Paste the following JSON object to the editor field

   {
     "jokeID": "1"
   }

8. Press the Test button again to run the test

9. Observe the failure in the test output. This is because your function has read only access to the "jokes" table, but is secretly trying to write to it.

Already done? Try some bonus steps!

Try it with the AWS CLI!

1. Make sure the AWSUSER and ACCOUNT_ID environment variables are still set.

   export AWSUSER=<your AWS user name>
   export ACCOUNT_ID=<your account ID>

2. Create a deployment package for your new function:

   pushd level-8/function
   npm install
   zip -r function.zip ./*
   popd

3. Update the function with the new code:

   aws lambda update-function-code --function-name "my-function-cli-${AWSUSER}" --zip-file fileb://level-8/function/function.zip

4. Invoke the function with a test event:

   aws lambda invoke --function-name "my-function-cli-${AWSUSER}" --cli-binary-format raw-in-base64-out --payload '{ "jokeID": "1" }' output.json --log-type Tail

Still bored? Then try it with Terraform!

1. Make sure your user variable is still set

   export TF_VAR_aws_user=<your AWS user name>

2. Copy the updated function code to your working directory

   cp -r level-8/function my-tf-module

3. Install the functions dependencies

   pushd my-tf-module/function
   npm install
   popd

4. Navigate to your Terraform module

   pushd my-tf-module

5. Apply the Terraform module again

   terraform apply

Level 9 - Do the Canary

To reach level 9, we have to correctly deploy our app using a canary deployment. These can help greatly to reduce errors in production. In this section, you will do a rolling deployment that gradually increases the load to the new version and rolls back on errors. To do so, run through the following steps:

1. Go to the AWS Lambda UI
2. Click on Functions in the left navigation
3. Choose the function my-function-AWSUSER, which you updated in level 4
4. Run npm install in the folder level-9/function
5. Create a zip file from the folder level-9/function and upload it to the function
6. Go to the "Versions" tab and click "Publish a new version", then click "Publish"
7. Click "Create alias" and call it "production"
8. Change something in the function code (e.g. add a console.log("new version"); statement)
9. Zip the folder again and upload it
10. Publish another version with the new source code

Now, through a canary deployment, we want to migrate the production alias from version 1 to version 2.

1. To allow CodeDeploy to access our function, we need to create the respective role. Head over to the IAM UI and create a new role

2. Choose "CodeDeploy" as the service and then "CodeDeploy for Lambda" as the use case

3. Call the role codedeploy-to-my-function-AWSUSER (replacing "AWSUSER" with your user name)

4. Visit the CodeDeploy UI

5. Create a new application and give it the same name as your function. Choose "AWS Lambda" as the "Compute platform"

6. Create a new deployment group and give it the same name as your function

7. For the "Service role", choose the one we have just created

8. The deployment configuration, should be set to "CodeDeployDefault.LambdaLinear10PercentEvery1Minute" to trigger a canary deployment which will roll out to another 10% of users every minute

9. Click "Create deployment" and choose "Use AppSpec editor" with "YAML"

10. Enter the following code into the text field (replacing AWSUSER with your user name):

    version: 0.0
    Resources:
      - my-function:
          Type: AWS::Lambda::Function
          Properties:
            Name: "my-function-AWSUSER"
            Alias: "production"
            CurrentVersion: "1"
            TargetVersion: "2"

11. Click "Create deployment"

12. You can now observe in real time how your production alias gets switched from version 1 to version 2 gradually using a canary deployment

Already done? Try some bonus steps!

Try it with Terraform!

1. Make sure your user variable is still set

   export TF_VAR_aws_user=<your AWS user name>

2. Navigate to the Terraform module

   cp level-9/advanced/terraform/* my-tf-module
   cp -r level-9/function my-tf-module

3. Install the functions dependencies

   pushd my-tf-module/function
   npm install
   popd

4. Navigate to your Terraform module

   pushd my-tf-module

5. Apply the Terraform module again

   terraform apply

6. Change something about the function code and apply again to publish a new version (notice the publish: true flag in function.tf)

7. Visit the CodeDeploy UI

8. Choose your application

9. Click "Create deployment" and choose "Use AppSpec editor" with "YAML"

10. Enter the following code into the text field (replacing AWSUSER with your user name):

    version: 0.0
    Resources:
      - my-function:
          Type: AWS::Lambda::Function
          Properties:
            Name: "my-function-tf-AWSUSER"
            Alias: "production"
            CurrentVersion: "1"
            TargetVersion: "2"

11. Click "Create deployment"

12. You can now observe in real time how your production alias gets switched from version 1 to version 2 gradually using a canary deployment