Do you want to access your database, control your system, or execute some code from another website? An API can do all of this for you, and they’re surprisingly easy to set up.
An API is a URL that you can perform GET, PUT, POST, and DELETE requests on to control another service. If you make one yourself, then you can build these APIs to do whatever you want behind the scenes. Common uses are providing database control, performing actions on third-party APIs (API-ception), or controlling another service.
Why use an API?
You may ask why we need an API when we can access the database directly or run the code on the website. There are a few massive advantages to APIs over running the code in your website.
Hide your access keys and tokens
This is possibly the most important reason to use an API. If you are accessing a database, then you’re going to need the database details as well as user and access token/key data.
If you access the database from the website, then you’re going to have all of these details in the source code of your site. This is really bad practice, as anyone can look into the source control and steal your details. This doesn’t sound too bad, but what if these are your AWS or Google Cloud Compute credentials? The people accessing your site could then use these to run whatever they want on your account, leaving you with a huge bill.
Running these processes from behind an API means no one can see any of the private details — they can’t steal them to use in their own projects. If you store your website code in GitHub or another public source control, then it also means that they aren’t visible there, either.
Run the code elsewhere
What if you aren’t using any other services and aren’t using any secret keys? If you are running a large or complex bit of code, or if you don’t want anyone else reading your code and discovering how it works, then you can still use an API.
Control who has access
Providing an API also allows you to restrict who is able to access the database or run the code. You can do this by requiring an API key. This key is used to identify the user making the request, and then allowing or rejecting the request.
This can be used to allow only a few people to access the service, or even to create a tier system. This is how a lot of paid APIs work. Everyone is given free but limited access, and then you allow payment for access to superior parts of the service or just a higher rate of requests.
Building the API
Now that we know some reasons why we might want to create an API, let’s do just that. We’re going to use API Gateway and AWS Lambdas, because it’s simpler than running a server. Make sure you have an AWS account and are logged in.
Setting up an API Gateway
We’ll start by opening the API Gateway service and clicking “Get Started”. On the next page, we need to select the “New API” option. Then we’ll give our API a name and description, and click “Create API”.
Clicking “Create API” will get us into the configuration page for the API.
The first thing we need to do is to add a resource onto the API. Using resources allows us to group similar API calls together using nested slashes. We are going to create an API that we can use to make recommendations on what to watch. Therefore we can have /tv-shows and /movies as two base methods.
Click the “Actions” dropdown and select “Create Resource”. Name your resources, making sure that they are both in the “/” path.
We want users to be able to go to “/movies/horror”or “/tv-shows/comedy”, and we can do this by adding path parameters. These are variables that we can access inside the API. To create one of these, we need to set the resource to {resourceName} as shown below. This can be done for “tv-shows”and “movies”.
Now that we have length and genre, we can create methods for getting and adding data to a table. Select one of the {genre} resources, click “Actions”, and then “Create Method”. This will create a small grey box below the resource which we can click. We are going to start with a GET request, so select that and click the tick button.
This is where we get to decide how to handle the request. We are going to use AWS Lambdas, but we need to create them before we can finish setting up the methods.
Creating the Lambdas
We are able to respond to these API requests using Lambdas, which is great as they only run when we need them to. They are also really easy to create, so that’s what we’ll do now.
In the Lambda console, click “Create function”. Then we can name our first API function movieAPI, set it to run Node 8.10, and “Create new role from template(s)”. We’ll name our new role “tableAPI” and add “Simple Microservice permissions” as the only template.
All code can be found at https://github.com/SamWSoftware/Projects/tree/master/movieAPI
Clicking “Create function” will send us into the Lambda window. Scroll down to the “Function code” section and we’ll change the code. The first thing we’re going to do is to check what request method was used.
exports.handler = async (event) => { console.log(event); if (event.httpMethod === 'PUT'){ let response = putMovie(event) return done(response); } else if (event.httpMethod === 'GET'){ let response = getMovie(event); return done(response); }};We’re going to start by writing the getMoviefunction. This function will start by getting the genrefrom the path parameters. This is where using path parameters can make this process easy.
const getMovie = event => { let genre = event.pathParameters.genre; return;}With the genre that the user requested, we are going to get a recommended movie for them. I copied these from 25 Top Films From Each Genre and added them to an object with the genre as the key. We can then get the film by getting the value of the genre requested.
const movies = { action: 'Desperado (1995)', fantasy: 'Inception (2010)', ... horror: 'Black Swan (2010)'}const getMovie = event => { let genre = event.pathParameters.genre; return movies[genre];}This means that the title of the movie is being passed into the done function. This function is used, as API Gateway expects the data to come back in a very specific format. This function turns a string into that required format.
const done = response => { return { statusCode: '200', body: JSON.stringify(response), headers: { 'Content-Type': 'application/json', 'Access-Control-Allow-Methods': '*', 'Access-Control-Allow-Origin': '*' } }}We can do a very similar thing for a tv-showsAPI function, reusing most of the code. Just change the function names and the movie suggestions to tv show.
Connecting the Lambdas to API Gateway
Back in API Gateway, we can add our new Lambdas to the methods we created earlier. We need to make sure that “Use Lambda Proxy integration” is selected and that we are pointing at the correct Lambda. Clicking “Save” will ask you for permissions to access this Lambda, to which we can give the “OK”.
Do this for the GET methods on both resources and we can start to test. Selecting the methods should now show a method execution diagram. This sounds complicated but the only bit we need is the “TEST” section.
Clicking “TEST” will open a new section where we can try out the API. There are lots of things you can set here, but the only one we care about is the Path {genre}. We need to set this to the genre we’re requesting. Entering “western” as the genre and hitting the “Test” button gets a response like this:
We got our API working! Now we need to make sure that other people can access it. There are two steps to this.
- We enable CORS — Select the “{genre}” resource and then click “Actions” and “Enable CORS”. Leave everything as defaults and, when asked, click “Yes, replace existing values”.
- Deploy our API — Click on “Actions” and “Deploy API”. Set the deployment stage to “[New Stage]” and then give your stage a name like “production” or “public”.
Once your API has deployed you should get a URL like this. This is the base of your API. You can add /movies/western to access your API.
https://{uniqueCode}.execute-api.eu-west-1.amazonaws.com/productionYour API URL might end up something like:
https://fds1fe31fes476s.execute-api.eu-west-1.amazonaws.com/production/movies/westernThat’s all for this article. In the next one we’ll connect this API to Dynamo tables and let users vote on their favourite movies in each genre. You can read that article below.
Building an API with Lambdas and API Gateway — Part 2
In the first part we created an API which passed requests through to a Lambda which returned the top tv show or movie…
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FAQs
How to build an API with Lambdas and API Gateway? ›
To expose a lambda function via an HTTP endpoint, you must first create an API Gateway endpoint and then attach the lambda function.
How to create an API with Lambda? ›- Create a lambda function. On your AWS Management Console go to Lambda: ...
- Write the lambda function. In your newly created lambda function, go to Function Code: ...
- Configure a test. Go to the test menu and click on configure tests. ...
- Build the API Gateway. ...
- Test Your API for real.
- Open the API Gateway console .
- Choose Create API.
- Under HTTP API, choose Build.
- Choose Add integration, and then choose an AWS Lambda function or enter an HTTP endpoint.
- For Name, enter a name for your API.
- Choose Review and create.
- Choose Create.
To expose a lambda function via an HTTP endpoint, you must first create an API Gateway endpoint and then attach the lambda function.
How to call API Gateway from Lambda Java? ›- Gather basic information. ...
- Include the AWS SDK to your project. ...
- Create the JsonApiGatewayCaller class extending AmazonWebServiceClient . ...
- Create the JsonApiGatewayCaller constructor. ...
- Create the ExecutionContext. ...
- Create the DefaultRequest. ...
- HTTP method execution. ...
- Final usage.
- Step 1: Create ASP.NET Core Web API project. Open Visual Studio, create New Project and select ASP.NET Core Web API template to create a new Web API project. ...
- Step 2: Install Amazon. Lambda. ...
- Step 3: Update . ...
- Step 4: Deploy Web API on AWS Lambda. ...
- Step 5: Enable Function Url for the Lambda. ...
- Step 6: Verify that API is working.
- Choose your API.
- Note your API's invoke URL.
- Verify your API's response. You should see the text "Hello from Lambda!" in your browser.
- Start the lambda function.
- Download data from a dummy API to local file system.
- Copy the downloaded files to AWS S3.
- Stop the lambda function.
- The lambda function will be scheduled to run every 5 minutes.
API calls are made from various external apps; they are processed by API Gateway, and are routed to Lambda for processing. Lambda may use other AWS services to complete a request, and, once complete, it sends back the response to the external app via API gateway.
How to create REST API serverless? ›- Setting Up the Local Environment.
- First, create a boilerplate serverless project to provide a template: create --template aws-nodejs --name trendmicro. ...
- service: trendmicro. frameworkVersion: '2' ...
- Building the API.
- 'use strict'; module.exports.hello = async (event) => {
What is REST API vs HTTP API? ›
REST APIs support more features than HTTP APIs, while HTTP APIs are designed with minimal features so that they can be offered at a lower price. Choose REST APIs if you need features such as API keys, per-client throttling, request validation, AWS WAF integration, or private API endpoints.
What is the difference between API and API gateway? ›The Differences Between API Management and API Gateways
API Gateways are components of an overall API management solution. While one provides a management solution foFr APIs, the other is a proxy service in front of your existing infrastructure.
The popular example of API Gateway is Netflix API Gateway. The Netflix streaming services are available on hundreds of different kinds of devices such as televisions, set-top boxes, smartphones, tablets, etc. It attempts to provide a one-size-fits-all API for its streaming service.
Can Lambda be used for REST API? ›Lambda proxy integration is a lightweight, flexible API Gateway API integration type that allows you to integrate an API method – or an entire API – with a Lambda function. The Lambda function can be written in any language that Lambda supports.
Is Lambda an API? ›Lambda API is a lightweight web framework for AWS Lambda using AWS API Gateway Lambda Proxy Integration or ALB Lambda Target Support. This closely mirrors (and is based on) other web frameworks like Express.
What is the difference between AWS Lambda API Gateway and load balancer? ›So, how do API gateways and load balancers differ? The main difference between these two services is that API gateways provide secure access to backend services, whereas load balancers distribute traffic between multiple servers.
How do I make a call to AWS API Gateway? ›To call a deployed API, clients submit requests to the URL for the API Gateway component service for API execution, known as execute-api . where {restapi_id} is the API identifier, {region} is the Region, and {stage_name} is the stage name of the API deployment.
Can Lambda call an external API? ›You can call an external API web-service/URL from Python in AWS Lambda using the requests library. Here is an example of how to do this: pythonCopy codeimport json. import requests.
How to create API Gateway in Python? ›- To start, from the API Gateway page, click the “Get Started” button to create a new API:
- Select “New API”, and then provide a descriptive name, like code_execute_api : ...
- Select “Create Resource” from the “Actions” drop-down.
- Name the resource execute , and then click “Create Resource”.
If it listens on a port, you can deploy it to AWS Lambda... AWS Lambda is an event-driven, serverless computing platform provided by Amazon as a part of Amazon Web Services. It is a computing service that runs code in response to events and automatically manages the computing resources required by that code.
Does API Gateway pass headers to Lambda? ›
In Lambda proxy integration, at run time, API Gateway maps an incoming request into the input event parameter of the Lambda function. The input includes the request method, path, headers, any query string parameters, any payload, associated context, and any defined stage variables.
How do I give API Gateway permission to invoke Lambda? ›In the left navigation pane, choose Authorization. Choose Manage authorization. Find the name of your Lambda authorizer, and then choose the Edit button next to the name of your Lambda authorizer. For Invoke permissions, choose Automatically grant API Gateway permission to invoke your Lambda function.
How to pass parameters from API Gateway to Lambda? ›To configure a REST API to pass query string parameters to a backend AWS Lambda function, use a Lambda custom integration. To pass query string parameters to an HTTP endpoint, use an HTTP custom integration. Important: Make sure that you supply the input data as the integration request payload.
How to deploy REST API in AWS? ›- Create a New REST API. a. In the AWS Management Console, click Services then select API Gateway under Application Services. ...
- Create a new resource and method. Create a new resource called /ride within your API. ...
- Deploy Your API. From the Amazon API Gateway console, choose Actions, Deploy API.
- Step 1: Using CloudWatch. ...
- Step 2: Customized Logging Output. ...
- Step 3: Logging HTTP Responses. ...
- Step 4: Accepting User Input. ...
- Step 5: Logging Meaningful Data. ...
- Step 6: Analyzing Our Data.
A callback is a pattern where you pass a function somewhere and it gets called later. Functional interfaces are a way of specifying what kind of function you expect. A lambda is a quick way of implementing a functional interface. Lambdas are useful if you want to use callbacks.
What is better than AWS Lambda? ›We have compiled a list of solutions that reviewers voted as the best overall alternatives and competitors to AWS Lambda, including Google App Engine, Azure App Service, Salesforce Heroku, and Red Hat OpenShift Container Platform. Have you used AWS Lambda before?
Why should I put lambda in VPC? ›Lambda functions always run inside VPCs owned by the Lambda service. As with customer-owned VPCs, this allows the service to apply network access and security rules to everything within the VPC.
What is the best way to create REST API? ›- Step 1: Create. Step 1.1: Create a project and add a REST API component. Step 1.2: Add a REST API component. Step 1.2: Design the REST API.
- Step 2: Deploy.
- Step 3: Test.
- Step 4: Manage.
API Gateway is the fundamental part of serverless API, because it is responsible for the connection between a defined API and the function handling requests to that API. Thundra Foresight empowers developers to build successful CI pipelines by providing deep analytics and debugging capabilities.
What can be used to create a REST API for a Lambda? ›
To build an API with Lambda integrations, you can use Lambda proxy integration or Lambda non-proxy integration. In Lambda proxy integration, the input to the integrated Lambda function can be expressed as any combination of request headers, path variables, query string parameters, and body.
How many types of API are there? ›There are four different types of APIs commonly used in web services: public, partner, private and composite.
How do I know if my API is REST or SOAP? ›SOAP APIs are limited to using XML and the format including the SOAP envelope, header, and body, as we saw in the example above. REST APIs are, however, format agnostic. While the most common format is JSON, formats such as XML, plain text, and XML are also valid for REST APIs.
Why is REST API called REST? ›REST stands for Representational State Transfer. This means that when a client requests a resource using a REST API, the server transfers back the current state of the resource in a standardized representation.
What is the best language to build an API? ›Some languages and frameworks used to write APIs are better and more efficient than others. From our experience in developing enterprise APIs, we have found that Python, Flask, Node, JS, and Express are the best languages for building EFFICIENT web application APIs.
Is it hard to build APIs? ›Complicated as it may sound, creating a basic API service is actually quite easy. Snippet below defines an API service using Python and Flask that allows everyone to retrieve a predefined list of users: If you are merely prototyping, such a basic API service would suffice.
How to create web API for beginners? ›- From the File menu, select New > Project.
- Enter Web API in the search box.
- Select the ASP.NET Core Web API template and select Next.
- In the Configure your new project dialog, name the project TodoApi and select Next.
- In the Additional information dialog: Confirm the Framework is . NET 7.0 (or later).
API Gateway provides tools for creating and documenting web APIs that route HTTP requests to Lambda functions. You can secure access to your API with authentication and authorization controls. Your APIs can serve traffic over the internet or can be accessible only within your VPC.
What is an API Gateway for dummies? ›An API gateway is a component of the app-delivery infrastructure that sits between clients and services and provides centralized handling of API communication between them. It also delivers security, policy enforcement, and monitoring and visibility across on-premises, multi-cloud, and hybrid environments.
What is the difference between API Gateway and microservices? ›The API Gateway offers a reverse proxy to redirect or route requests (layer 7 routing, usually HTTP requests) to the endpoints of the internal microservices. The gateway provides a single endpoint or URL for the client apps and then internally maps the requests to a group of internal microservices.
What are the 3 types of APIs and give examples for each? ›
- REST, a collection of guidelines for lightweight, scalable web APIs.
- SOAP, a stricter protocol for more secure APIs.
- RPC, a protocol for invoking processes that can be written with XML (XML-RPC) or JSON (JSON-RPC).
- Open the API Gateway console .
- Choose Create API.
- Under HTTP API, choose Build.
- Choose Add integration, and then choose an AWS Lambda function or enter an HTTP endpoint.
- For Name, enter a name for your API.
- Choose Review and create.
- Choose Create.
That said, the disadvantages of API gateways include: Potentially slower performance: API gateways create another layer that traffic needs to pass through, which could potentially slow application performance — especially when the gateway is poorly configured.
Can we call Lambda without API Gateway? ›Originally, if you wanted to invoke a Lambda function publicly via HTTPS you would need to set up and configure AWS API Gateway or AWS Elastic Load Balancing and pay additional fees once you exceeded their free tier. Fortunately, Function URLs don't incur an additional cost 🎉.
What does Lambda stand for? ›Lambda, the 11th letter of the Greek alphabet, is the symbol for wavelength. In optical fiber networking, the word lambda is used to refer to an individual optical wavelength.
Is Lambda a Paas or SaaS? ›AWS Lambda is a serverless, event-driven compute service that lets you run code for virtually any type of application or backend service without provisioning or managing servers. You can trigger Lambda from over 200 AWS services and software as a service (SaaS) applications, and only pay for what you use.
Is Lambda a load balancer? ›Elastic Load Balancing supports Lambda functions as a target for an Application Load Balancer. Use load balancer rules to route HTTP requests to a function, based on path or header values. Process the request and return an HTTP response from your Lambda function.
Do we need both API gateway and load balancer? ›An organization's approach to managing network traffic doesn't need to use only API gateways or load balancers. Both services can function together, although they do not require each other to work. For instance, the API gateway connects between microservices.
Is API gateway and Lambda synchronous? ›Similarly to the API Gateway integration, Lambda can also serve HTTP requests received by an Application Load Balancer (ALB) 9. Also as API Gateway, the ALB will invoke the Lambda function synchronously.
Do I need a load balancer for AWS API gateway? ›Load balancing the API Gateway's
The API gateway's accessibility is critical to the application's accessibility. There must be a load balancer for the API gateway that can adapt to changes in microservices, such as versioning and dynamic scaling.
How many API calls can API Gateway handle? ›
API Gateway has account-level quotas, per Region. The throttle quota is 10,000 requests per second (RPS) with an additional burst capacity provided by the token bucket algorithm. The maximum bucket capacity is 5,000 requests per account and Region.
What is difference between HTTP API and REST API? ›REST APIs support more features than HTTP APIs, while HTTP APIs are designed with minimal features so that they can be offered at a lower price. Choose REST APIs if you need features such as API keys, per-client throttling, request validation, AWS WAF integration, or private API endpoints.
How does API Gateway connect to Lambda? ›Lambda Proxy integration is a simplified configuration for the integration between Lambda functions and API Gateway. The API Gateway sends the entire request as an input to a backend Lambda function. Response-wise, API Gateway transforms the Lambda function output back to a frontend HTTP response.
How do I call a REST API from Lambda? ›...
To test your API
- Choose your API.
- Note your API's invoke URL.
- Verify your API's response. You should see the text "Hello from Lambda!" in your browser.
- Create the Student Class.
- Setup Your SQLite Database Connection.
- Make a Get Request.
- Get Record By ID.
- POST Request.
- Update Request.
- DELETE Request.
- Select GET from the dropdown.
- Type the entry point of our API instance + /users (the endpoint)
- Hit Send.
- Check the status code returned by our API (we should see 200 OK )
- View our API's response, which is users. csv in JSON (like a dictionary) format.
It's not always necessary to use a Lambda function. In some situations, you may have other alternatives that can improve performance. For functions that act as orchestrators, calling other services and functions and coordinating work, this can result in idle time in the function.
How do I automate AWS Lambda deployment? ›- Create Resources in a pre-production account. ...
- Create IAM Roles in the Production Account and required policies. ...
- Create a CloudFormation Deployment role. ...
- Policy 1: For Cloudformation to deploy the application in the Production account. ...
- Policy 2: For Cloudformation to perform required IAM actions.
- Open the API Gateway console.
- Choose Create API. -or- ...
- For Choose an API type, in the REST API pane, choose Build.
- In Create new API, choose New API.
- In Settings , do the following: For API name , enter a name that describes your API's purpose. ...
- Choose Create API.
- Step 1: Create ASP.NET Core Web API project. Open Visual Studio, create New Project and select ASP.NET Core Web API template to create a new Web API project. ...
- Step 2: Install Amazon. Lambda. ...
- Step 3: Update . ...
- Step 4: Deploy Web API on AWS Lambda. ...
- Step 5: Enable Function Url for the Lambda. ...
- Step 6: Verify that API is working.
How much payload can Lambda send to API Gateway? ›
API Gateway has a response payload limit of 10 MB.
Is traffic between API Gateway and Lambda encrypted? ›The API gateway method is configured by the user to pass through any requests directly to a specific lambda backend, so any HTTP requests to the API method will be always be forwarded to the lambda as is. How would it know which Lambda to use? Everything is encrypted including the URL and Host header.
How does API Gateway connect to Lambda in VPC? ›Api gateway communicates with lambda using aws internal network. AWS_PROXY is special integration type for lambda only. There is no internet traffic involved, even if lambda is not in vpc.
Is API Gateway and Lambda synchronous? ›Similarly to the API Gateway integration, Lambda can also serve HTTP requests received by an Application Load Balancer (ALB) 9. Also as API Gateway, the ALB will invoke the Lambda function synchronously.
How does API Gateway work? ›An API gateway accepts API requests from a client, processes them based on defined policies, directs them to the appropriate services, and combines the responses for a simplified user experience. Typically, it handles a request by invoking multiple microservices and aggregating the results.
Is Lambda inside or outside VPC? ›Lambda functions always run inside VPCs owned by the Lambda service. As with customer-owned VPCs, this allows the service to apply network access and security rules to everything within the VPC.
Which VPC does Lambda run in? ›You can configure a Lambda function to connect to private subnets in a virtual private cloud (VPC) in your AWS account. Use Amazon Virtual Private Cloud (Amazon VPC) to create a private network for resources such as databases, cache instances, or internal services.
How do I call a VPC endpoint from Lambda? ›- Open the Endpoints page of the Amazon VPC console.
- Choose Create Endpoint.
- For Service category, verify that AWS services is selected.
- For Service Name, choose com. ...
- Choose a VPC and subnets.
- To enable private DNS for the interface endpoint, select the Enable DNS Name check box.
So, how do API gateways and load balancers differ? The main difference between these two services is that API gateways provide secure access to backend services, whereas load balancers distribute traffic between multiple servers.
What two types of APIs can Amazon API Gateway handle? ›Using API Gateway, you can create RESTful APIs and WebSocket APIs that enable real-time two-way communication applications.
How do I invoke private API Gateway from Lambda? ›
- Choose your API.
- Choose Actions and then choose Create method.
- Choose GET and then choose the check mark to confirm your choice.
- For Integration Type, select Lambda function.
- Select Use Lambda proxy integration.
That said, the disadvantages of API gateways include: Potentially slower performance: API gateways create another layer that traffic needs to pass through, which could potentially slow application performance — especially when the gateway is poorly configured.
Which API Gateway is best for microservices? ›Kong gateway is the perfect choice for microservices and API management. It is used by companies such as Netflix, Hulu, and LinkedIn. Proxies can be configured for your services, and they can be served over SSL, or by using WebSockets.
What is simple example of API Gateway? ›The popular example of API Gateway is Netflix API Gateway. The Netflix streaming services are available on hundreds of different kinds of devices such as televisions, set-top boxes, smartphones, tablets, etc. It attempts to provide a one-size-fits-all API for its streaming service.