Testing in AWS. Let s go back to the lambda function(sample-hello) you made before. - AWS Lambda - Select Simple-Hello

Transcription

1 Testing in AWS Let s go back to the lambda function(sample-hello) you made before. - AWS Lambda - Select Simple-Hello

2 Testing in AWS Simulate events and have the function react to them. Click the down arrow button in Lambda console and then click configuration test event

3 Testing in AWS Select Create new test event in combo-box Event Name is Test Event and Copy and Paste it below code. { } "name": "kmu" Click create

4 Testing in AWS You can see the Success result. Result is Hello {NAME} and you can see the logs in the below block.

5 Testing in AWS Add error test to check when input does not have a key of name. Click the down arrow button in Lambda console and then click configuration test event

6 Testing in AWS Select Create new test event in combo-box Event Name is ErrorEvent and Copy and Paste it below code.

7 Testing in AWS You can see the Success result but you didn t handle error (for example: key is missing), you will learn in Versioning section

8 Using Lambda with API Gateway Moreover, you can invoke Simple-Hello (Lambda functions) through the API Gateway as well as AWS Console and CLI. Simple-Hello

9 Using Lambda with API Gateway What is API Gateway? In AWS, the API Gateway is a key service that allows developers to create a RESTful API via HTTP - No more cumbersome HTTP server setup Using Lambda as a backend service with API Gateway as a proxy to deliver users requests to backend

10 Using Lambda with API Gateway API Gateway is an interface between back-end services (including Lambda) and client applications (web, mobile, or desktop).

11 Using Lambda with API Gateway API Gateway makes serverless applications easier to build and maintain than traditional server-based approach. In a more traditional system, You - need to provision EC2 instances - configure load balancing using Elastic Load Balancer (ELB) - maintain software on each server. The API Gateway removes the need to do all that by providing an API and connect it to services in minutes. In us-west-2, the API Gateway cost is $3.50 per million API calls received

12 Using Lambda with API Gateway We ll need to set up an API Gateway and invoke Simple-Hello Lambda function. - In the AWS console, click API Gateway.

13 Using Lambda with API Gateway - Click Get Started

14 Using Lambda with API Gateway - Select NEW API and type in a name for your API, such as Hello-API - Click Create API to create your first API.

15 Using Lambda with API Gateway - This is what will look like after creation. - Other than many features, we will focus on Resources-Stages.

16 Using Lambda with API Gateway APIs in the Gateway are built around resources. Every resource can be combined with an HTTP method such as HEAD, GET, POST, PUT, OPTIONS, PATCH, or DELETE. You re going to create a resource called hello and combine it with a GET method. In the API you just created, follow these steps: - Click Actions and select Create Resource.

17 Using Lambda with API Gateway - Type hello in the Resource Name field. The Resource Path filed should automatically fill. - Click the Create Resource button to create and save the resource.

18 Using Lambda with API Gateway - The left list should now show the /hello resource.

19 Using Lambda with API Gateway - Make sure /hello resource is selected, and click Actions again. Click Create Method.

20 Using Lambda with API Gateway - Under the /hello resource, click the drop-down and select GET. - Click the check mark button to save.

21 Using Lambda with API Gateway - Having saved the GET method, you should immediately see the Integration Request screen

22 Using Lambda with API Gateway - Click the Lambda Function radio button.

23 Using Lambda with API Gateway - Select your region (us-east-2) from the Lambda Region drop-down menu.

24 Using Lambda with API Gateway - Type Sample-Hello in the Lambda Function text box. - Click Save.

25 Using Lambda with API Gateway - Click OK if you re asked if it s okay to add permissions to the Lambda function.

26 Using Lambda with API Gateway - This is what will look like after creating GET Method

27 Using Lambda with API Gateway Mappings If you look at Simple-Hello.js again, you ll see code that refers to event.name. This is the input of the event object when API Gateway passes through to the Lambda. To make this input available in a Lambda function, you need to create a mapping in the API Gateway

28 Using Lambda with API Gateway - Click the GET method under the /hello resource. Click Integration Request.

29 Using Lambda with API Gateway - Expand Body Mapping Templates.

30 Using Lambda with API Gateway - Click Add Mapping Template. - Type in application/json and click the check mark button.

31 Using Lambda with API Gateway - Select Yes, Secure This Integration if you see a dialog box titled Change Passthrough Behavior. - In the Template box type in the code. Click Save once you re finished. { } #if( $input.params('name').tostring()!= "" ) "name" : $input.params('name') #end

32 Using Lambda with API Gateway Finally, you need to deploy the API and get a URL to invoke the Simple-Hello function. - In the API Gateway, make sure your API is selected. (click /, not /hello) - Click Actions. Select Deploy API.

33 Using Lambda with API Gateway - In the pop-up, select [New Stage] - Type greet as the Stage Name. - Click Deploy to provision the API

34 Using Lambda with API Gateway - You see will show the Invoke URL and a number of options.

35 Using Lambda with API Gateway - From Stages menu, select greet, /hello, GET - Copy the Invoke URL that appears - It will look like - We will use this URL to invoke Simple-Hello Lambda with input as name

36 Using Lambda with API Gateway - Copy [YOUR NAME] - Paste it into your new tab browser and hit enter. You will see something like this - You can put anything in [yourname] and Hello [yourname] will appear in web browser.

37 Registered Event from AWS Lambda - Visit AWS Lambda and select Simple-Hello, you will see API Gateway in the trigger section

38 Lambda execution mechanism - container reuse Lambda functions execute in a container (sandbox) - Providing minimal isolation from other functions - Allocating resources (e.g., memory, disk space, and CPU) Container can easily come and go out of a machine Invoking a Lambda function for the first time - A new container is initialized (in cold status) - The code for the function is loaded - If a function is rerun within a certain period, Lambda may reuse the same container (warm status) - In the warm status, initialization process is skipped, thus making it available to execute code quicker.

39 Container reuse - Cold and warm Lambda An exercise to test the effect of warm and cold container Choose Simple-Hello in the AWS Lambda console. Click the Test button in the console.

40 Cold and warm Lambda Have a look at the duration in the summary in the bottom-left corner Then run the test again and look at the duration in the summary (run again in 1 second)

41 Cold and warm Lambda The execution duration of the first run (35 msec) is much longer than the second run (0.7 msec). - An effect from the container reuse The first time the function is run (when it s cold), the container needs to be created and the environment needs to be initialized. A lengthy initialization time may be especially noticeable in complex functions that have multiple dependencies.

42 Cold and warm Lambda It is good to reduce cold starts to make the application appear more responsive Strategy to reduce cold starts - Schedule the function (using scheduled events) to run periodically to keep it warm In the designer tab of a Lambda function (Simple-Hello), click CloudWatch events in the Add Triggers column

43 Cold and warm Lambda With Cloudwatch Events, you can trigger to run lambda function every 5 minutes (you can choose the time duration - cron expression is usable)

44 Strategy to reduce start time Move initialization and setup code out of the event handler. If a container is warm, this code won t run.

45 Strategies to reduce start time Increase the amount of memory allocated to the Lambda function. The CPU share is (proportionally) based on the amount of memory allocated to the function. - Example: Allocation of 256 MB to your Lambda function will receive twice the CPU share than 128 MB allocation. The more memory and CPU share the function has, the quicker it will initialize. Reduce as much of your code as possible - Remove unnecessary modules and requires() import statements - Fewer modules to include and initialize will help startup performance. Experiment with other languages - Different language has different cold start time (Java is somewhat longer)

46 Price of using Lambda Price model of Lambda function execution - the number of request - elapsed time of an execution: duration is calculated from the time your code begins executing until it returns or otherwise terminates, rounded up to the nearest 100ms Unit of GB-seconds - Product of allocated memory in MB and the duration of function execution in seconds The Lambda free tier - 1M free requests per month - 400,000 GB-seconds of compute time per month = 128MB for 37 days Price after the free tier - $0.20 per 1M requests - $ for every GB-second

47 Price of using Lambda Lambda pricing example - Assumption: 512MB of memory to a function, executes 3M times in one month, 1 second per each run - Total compute time = 3M * 512MB/1024 = 1,500,000 GB-S = $25 - Monthly request charge = 3M * $0.2/M = $0.6 - Total monthly charge = $25.6 (excluding the free-tier usage)

48 Logging Message logging in AWS Lambda can be done by console.log("message") - console.error(), console.warn(), and console.info() are doable Ways to check log messages - In the AWS Lambda execution pages - AWS CloudWatch service (more details later) The callback function will also log to a CloudWatch log stream for a non-null value in the first parameter.

49 Versioning Lambda functions Versioning allows developers to create new versions of functions without overwriting previous ones. An older version can still be accessed but it can t be changed. - Each version of a function has its own unique ARN, and each version can be invoked.

50 Lambda function versioning To create a new version of a function, follow these steps 1. Open the Lambda console in AWS and click a function. 2. Choose Actions and choose Publish New Version.

51 Versioning 3. Type a description in the dialog box. This description will be added to the version you re about to create. 4. Choose Publish to close the dialog box

52 Versioning If you click the Qualifiers drop-down and then select the Versions tab, you ll see all current versions of the function. The most recent version is always identified as $LATEST. If you don t specify a version number when invoking a function, this is the function that s invoked.

53 Versioning 5. Select LATEST version

54 Versioning 6. Change callback call module of Simple-Hello.js callback(null, "Hello " + event.name); to if (typeof event.name === 'undefined') { callback("there is no key named name", null); } else { callback(null, "Hello " + event.name); } It checks for if event object has property called name. If it hasn t, it will return an error.

55 Versioning 7. Click save 8. Open the Lambda console in AWS and click a function. 9. Choose Actions and choose Publish New Version.

56 Versioning 10. Type a description in the dialog box. This description will be added to the version you re about to create. 11. Choose Publish to close the dialog box

57 Versioning 12. Choose ErrorTest event 13. Click test Now you can see the result:fail because you added error callback function.

58 Alias to track different versions Aliases An alias is a pointer or a shortcut to a specific version of a Lambda function Each alias has an ARN just like a function - It can be mapped to point to any function (or version) but not to another alias - Switching between versions becomes easy with aliases

59 Alias to track different versions Example scenarios where alias is beneficial You have three versions of a function - Version 1 is in production - Version 2 is being tested in a staging - $LATEST is the current development version You ve finished testing function version 2 and want to promote it to production. - You have to update every event source that references function 1 (the current production) to reference function 2. This isn t ideal because it may mean a redeployment of your code and multiple updates throughout your system.

60 Alias to track different versions With an alias, this scenario becomes into easier to manage: 1. Create three aliases called dev, staging, and production. 2. Assign the right alias to the right version of the function: - The production alias points to version 1 - The staging alias points to version 2 - The dev alias points to $LATEST 3. Configure event sources to point to an alias instead of a specific version of a function. It is really similar to symbolic link in Linux

61 Alias to track different versions Whenever you need to update the system to use a new version of a function, change the alias to point to that new version instead. Event sources remain ignorant of the fact that an alias now points to a new version of a function and continue to operate as normal.

62 Aliases To create an alias for a function, follow these steps: 1. Choose Lambda in the AWS console and choose Simple-Hello function.

63 Aliases 2. Choose Actions. 3. Choose Create alias.

64 Aliases 4. In the dialog box enter a name for the alias, such as dev or production, a description, and select the version that the alias should point to. This time point to 1 - test for versioing. 5. Choose Submit to create the alias and close the dialog box.

65 Aliases 7. Create alias one more. Name it as a dev and choose version another version. Choose version 2 - error-handle-version. 8. Choose Submit

66 Aliases To view aliases for a function, use the Qualifiers drop-down, just as you did with versions. A tab in the drop-down allows you to switch the view between versions and aliases.

67 Aliases We are going to see how alias can be used to better manage versions with an application with API Gateway Choose API Gateway in the AWS console and select Hello-API

68 Aliases Select Get method and select integration request

69 Aliases Rename the Lambda function : Simple-Hello > Simple-Hello:prod

70 Aliases Select mapping template > application/json > choose Empty template or make the empty template { } #if( $input.params('name').tostring()!= "" ) "name" : $input.params('name') #end

71 Aliases Click Actions. Select Deploy API.

72 Aliases - In the pop-up, select [New Stage] - Type prod as the Stage Name. - Click Deploy to provision the API

73 Aliases - From Stages menu, select prod, /hello, GET - Copy the Invoke URL that appears - It will look like - We will use this URL to invoke Simple-Hello:prod Lambda

74 Aliases We will serve Simple-Hello:dev Lambda function Select Get method and select integration request

75 Aliases Rename the Lambda function : Simple-Hello:prod > Simple-Hello:dev

76 Aliases Click Actions Deploy API - In the pop-up, select [New Stage] - Type dev as the Stage Name. - Click Deploy to provision the API

77 Aliases - From Stages menu, select dev, /hello, GET - Copy the Invoke URL that appears - It will look like - We will use this URL to invoke Simple-Hello:dev Lambda

78 Aliases Choose Lambda in the AWS console and choose Simple-Hello function And choose SImple-Hello:prod

79 Aliases Change the version 1 to 2 and click save

80 Aliases - Back Stages menu, select prod, /hello, GET - Click the URL again and you can see the response from Simple-Hello:prod which points version 2

81 Aliases To delete an alias, choose Actions and select Delete Alias. Doing this deletes the alias and any related event source mappings that point to it. Everything else, including function versions, is left intact.

82 Setting up your cloud

83 Setting up your cloud We are going to cover general usage of cloud from the following perspective Security model and identity management in AWS Logging, alerting, and monitoring custom metrics Monitoring and estimating AWS costs

84 Creating and managing IAM users IAM user is an entity in AWS that identifies - A human user - An application - A service. A user normally has a set of credentials and permissions - a user lambda to allow Lambda functions.

85 Creating and managing IAM users IAM user page shows a summary page and an ARN for a fictional user named lambda. - AWS console IAM Users in the navigation pane click the name of the user you want to view.

86 Creating and managing IAM users IAM users to represent - human users - applications - services. Access key - Asymmetric key to access AWS API services - It can be generated when a user is created - Creating on-demand - Access key id (public) - Secret access key (private) Password-based access is supported for a user

87 Creating and managing IAM users To create a password for an IAM user, follow these steps: 1. In the IAM console, click Users in the navigation pane. 2. Create for real person. Click the Add your button

88 Creating and managing IAM users 3. Give your new IAM user a name worker, select the Programmatic access check box, and AWS Management console Access. You choose whether to enable or disable console access, type in a new custom password, or let the system auto-generate one. You can also force the user to create a new password at the next sign-in.

89 Creating and managing IAM users 2-3. Don t select anything in the Set Permissions for worker. Click Next:Review to proceed. Click Create User.

90 Creating and managing IAM users You can see new created user.