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1 | | -# CoreUtilities |
| 1 | +# Lambda Powertools for Java - Core Utilities Example |
2 | 2 |
|
3 | | -This project contains source code and supporting files for a serverless application that you can deploy with the SAM CLI. It includes [Powertools for AWS Lambda (Java) for operational best practices](https://github.com/aws-powertools/powertools-lambda-java), and the following files and folders. |
| 3 | +This project demonstrates the Lambda for Powertools Java module - including |
| 4 | +[logging](https://docs.powertools.aws.dev/lambda/java/core/logging/), |
| 5 | +[tracing](https://docs.powertools.aws.dev/lambda/java/core/tracing/), and |
| 6 | +[metrics](https://docs.powertools.aws.dev/lambda/java/core/metrics/). |
4 | 7 |
|
5 | | -- HelloWorldFunction/src/main - Code for the application's Lambda function. |
6 | | -- events - Invocation events that you can use to invoke the function. |
7 | | -- HelloWorldFunction/src/test - Unit tests for the application code. |
8 | | -- template.yaml - A template that defines the application's AWS resources. |
| 8 | +It is made up of the following: |
9 | 9 |
|
10 | | -The application uses several AWS resources, including Lambda functions and an API Gateway API. These resources are defined in the `template.yaml` file in this project. You can update the template to add AWS resources through the same deployment process that updates your application code. |
11 | | - |
12 | | -If you prefer to use an integrated development environment (IDE) to build and test your application, you can use the AWS Toolkit. |
13 | | -The AWS Toolkit is an open source plug-in for popular IDEs that uses the SAM CLI to build and deploy serverless applications on AWS. The AWS Toolkit also adds a simplified step-through debugging experience for Lambda function code. See the following links to get started. |
14 | | - |
15 | | -* [PyCharm](https://docs.aws.amazon.com/toolkit-for-jetbrains/latest/userguide/welcome.html) |
16 | | -* [IntelliJ](https://docs.aws.amazon.com/toolkit-for-jetbrains/latest/userguide/welcome.html) |
17 | | -* [VS Code](https://docs.aws.amazon.com/toolkit-for-vscode/latest/userguide/welcome.html) |
18 | | -* [Visual Studio](https://docs.aws.amazon.com/toolkit-for-visual-studio/latest/user-guide/welcome.html) |
| 10 | +- [App.java](src/main/java/helloworld/App.java) - Code for the application's Lambda function. |
| 11 | +- [events](events) - Invocation events that you can use to invoke the function. |
| 12 | +- [AppTests.java](src/test/java/helloworld/AppTest.java) - Unit tests for the application code. |
| 13 | +- [template.yaml](template.yaml) - A template that defines the application's AWS resources. |
19 | 14 |
|
20 | 15 | ## Deploy the sample application |
21 | 16 |
|
22 | 17 | This sample is based on Serverless Application Model (SAM). To deploy it, check out the instructions for getting |
23 | 18 | started with SAM in [the examples directory](../README.md) |
24 | 19 |
|
25 | | -## Use the SAM CLI to build and test locally |
26 | | - |
27 | | -Build your application with the `sam build` command. |
28 | | - |
29 | | -```bash |
30 | | -Coreutilities$ sam build |
31 | | -``` |
32 | | - |
33 | | -The SAM CLI installs dependencies defined in `HelloWorldFunction/pom.xml`, creates a deployment package, and saves it in the `.aws-sam/build` folder. |
34 | | - |
35 | | -Test a single function by invoking it directly with a test event. An event is a JSON document that represents the input that the function receives from the event source. Test events are included in the `events` folder in this project. |
36 | | - |
37 | | -Run functions locally and invoke them with the `sam local invoke` command. |
38 | | - |
39 | | -```bash |
40 | | -Coreutilities$ sam local invoke HelloWorldFunction --event events/event.json |
41 | | -``` |
| 20 | +## Test the application |
42 | 21 |
|
43 | | -The SAM CLI can also emulate your application's API. Use the `sam local start-api` to run the API locally on port 3000. |
| 22 | +Once the app is deployed, you can invoke the endpoint like this: |
44 | 23 |
|
45 | 24 | ```bash |
46 | | -Coreutilities$ sam local start-api |
47 | | -Coreutilities$ curl http://localhost:3000/ |
48 | | -``` |
49 | | - |
50 | | -The SAM CLI reads the application template to determine the API's routes and the functions that they invoke. The `Events` property on each function's definition includes the route and method for each path. |
51 | | - |
52 | | -```yaml |
53 | | - Events: |
54 | | - HelloWorld: |
55 | | - Type: Api |
56 | | - Properties: |
57 | | - Path: /hello |
58 | | - Method: get |
| 25 | + curl https://[REST-API-ID].execute-api.[REGION].amazonaws.com/Prod/hello/ |
59 | 26 | ``` |
60 | 27 |
|
61 | | -## Add a resource to your application |
62 | | -The application template uses AWS Serverless Application Model (AWS SAM) to define application resources. AWS SAM is an extension of AWS CloudFormation with a simpler syntax for configuring common serverless application resources such as functions, triggers, and APIs. For resources not included in [the SAM specification](https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md), you can use standard [AWS CloudFormation](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-template-resource-type-ref.html) resource types. |
| 28 | +The response itself isn't particularly interesting - you will get back some information about your IP address. If |
| 29 | +you go to the Lambda Console and locate the lambda you have deployed, then click the "Monitoring" tab you will |
| 30 | +be able to find: |
63 | 31 |
|
64 | | -## Fetch, tail, and filter Lambda function logs |
| 32 | +* **View X-Ray traces** - Display the traces captured by the traces module. These include subsegments for the |
| 33 | +different function calls within the example |
| 34 | +* **View Cloudwatch logs** - Display the structured logging output of the example |
65 | 35 |
|
66 | | -To simplify troubleshooting, SAM CLI has a command called `sam logs`. `sam logs` lets you fetch logs generated by your deployed Lambda function from the command line. In addition to printing the logs on the terminal, this command has several nifty features to help you quickly find the bug. |
67 | | - |
68 | | -`NOTE`: This command works for all AWS Lambda functions; not just the ones you deploy using SAM. |
| 36 | +Likewise, from the CloudWatch dashboard, under **Metrics**, **all metrics**, you will find the namespaces `Another` |
| 37 | +and `ServerlessAirline`. The values in each of these are published by the code in |
| 38 | +[App.java](src/main/java/helloworld/App.java). |
69 | 39 |
|
| 40 | +You can also watch the trace information or log information using the SAM CLI: |
70 | 41 | ```bash |
71 | | -Coreutilities$ sam logs -n HelloWorldFunction --stack-name <Name-of-your-deployed-stack> --tail |
72 | | -``` |
73 | | - |
74 | | -You can find more information and examples about filtering Lambda function logs in the [SAM CLI Documentation](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-logging.html). |
75 | | - |
76 | | -## Unit tests |
77 | | - |
78 | | -Tests are defined in the `HelloWorldFunction/src/test` folder in this project. |
79 | | - |
80 | | -```bash |
81 | | -Coreutilities$ cd HelloWorldFunction |
82 | | -HelloWorldFunction$ mvn test |
83 | | -``` |
84 | | - |
85 | | -## Cleanup |
86 | | - |
87 | | -To delete the sample application that you created, use the AWS CLI. Assuming you used your project name for the stack name, you can run the following: |
88 | | - |
89 | | -```bash |
90 | | -aws cloudformation delete-stack --stack-name <Name-of-your-deployed-stack> |
91 | | -``` |
92 | | - |
93 | | -# Appendix |
94 | | - |
95 | | -## Powertools |
96 | | - |
97 | | -**Tracing** |
98 | | - |
99 | | -[Tracing utility](https://docs.powertools.aws.dev/lambda-java/core/tracing/) provides functionality to reduce the overhead of performing common tracing tasks. It traces the execution of this sample code including the response and exceptions as tracing metadata - You can visualize them in AWS X-Ray. |
100 | | - |
101 | | -**Logger** |
102 | | - |
103 | | -[Logging utility](https://docs.powertools.aws.dev/lambda-java/core/logging/) creates an opinionated application Logger with structured logging as the output, dynamically samples a percentage (samplingRate) of your logs in DEBUG mode for concurrent invocations, log incoming events as your function is invoked, and injects key information from Lambda context object into your Logger - You can visualize them in Amazon CloudWatch Logs. |
104 | | - |
105 | | -**Metrics** |
106 | | - |
107 | | -[Metrics utility](https://docs.powertools.aws.dev/lambda-java/core/metrics/) captures cold start metric of your Lambda invocation, and could add additional metrics to help you understand your application KPIs - You can visualize them in Amazon CloudWatch. |
108 | | - |
109 | | -## Resources |
110 | | - |
111 | | -See the [AWS SAM developer guide](https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/what-is-sam.html) for an introduction to SAM specification, the SAM CLI, and serverless application concepts. |
112 | | - |
113 | | -Check the [Powertools for AWS Lambda (Java)](https://docs.powertools.aws.dev/lambda-java/) for more information on how to use and configure such tools |
| 42 | +# Tail the logs |
| 43 | +sam logs --tail $MY_STACK_NAME |
114 | 44 |
|
115 | | -Next, you can use AWS Serverless Application Repository to deploy ready to use Apps that go beyond hello world samples and learn how authors developed their applications: [AWS Serverless Application Repository main page](https://aws.amazon.com/serverless/serverlessrepo/) |
| 45 | +# Tail the traces |
| 46 | +sam traces --tail |
| 47 | +``` |
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