Popular gateways (Kong, AWS API Gateway, Nginx) in Microservices - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the default port for Nginx gateway.

Microservices

server {
    listen [1];
    server_name localhost;
}

Drag options to blanks, or click blank then click option'

A8080

B80

C443

D3000

Attempts:

3 left

💡 Hint

Common Mistakes

Using port 443 which is for HTTPS.

Using arbitrary ports like 3000 or 8080 without configuration.

The default port for HTTP traffic in Nginx is 80.

2fill in blank

medium

Complete the code to define an AWS API Gateway REST API resource path.

Microservices

Resources:
  MyResource:
    Type: AWS::ApiGateway::Resource
    Properties:
      [1]: /myresource

Drag options to blanks, or click blank then click option'

AStageName

BEndpointConfiguration

CResourcePath

DPathPart

Attempts:

3 left

💡 Hint

Common Mistakes

Using StageName which defines deployment stage.

Using EndpointConfiguration which defines endpoint types.

In AWS API Gateway, the resource path segment is defined using PathPart.

3fill in blank

hard

Fix the error in the Kong configuration snippet to enable proxying to the upstream service.

Microservices

services:
  - name: example-service
    url: http://[1]:8080
    routes:
      - name: example-route
        paths:
          - /example

Drag options to blanks, or click blank then click option'

Aexample.com

B127.0.0.1

Clocalhost

Dupstream

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'example.com' which may not resolve to the local service.

Using 'upstream' which is not a valid hostname.

The url field must point to the upstream service address. Using localhost is correct if the service runs locally.

4fill in blank

hard

Fill both blanks to configure Nginx to proxy requests to a backend service on port 5000.

Microservices

location /api/ {
    proxy_pass http://[1]:[2];
}

Drag options to blanks, or click blank then click option'

Alocalhost

B5000

C8080

D127.0.0.1

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong port like 8080.

Using IP 127.0.0.1 instead of localhost (both work but question expects localhost).

Nginx proxies to the backend service running on localhost at port 5000.

5fill in blank

hard

Fill all three blanks to define an AWS API Gateway method with HTTP GET integration to a Lambda function.

Microservices

Resources:
  MyMethod:
    Type: AWS::ApiGateway::Method
    Properties:
      HttpMethod: [1]
      ResourceId: !Ref MyResource
      Integration:
        Type: [2]
        IntegrationHttpMethod: [3]

Drag options to blanks, or click blank then click option'

AGET

BAWS_PROXY

CPOST

DPUT

Attempts:

3 left

💡 Hint

Common Mistakes

Using PUT or GET as integration HTTP method instead of POST.

Using wrong integration type.

The method is GET, integration type is AWS_PROXY for Lambda proxy, and integration HTTP method is POST.

Practice

1. Which of the following is a primary role of API gateways like Kong, AWS API Gateway, or Nginx in microservices?

easy

A. Control and protect communication between services

B. Store large amounts of data

C. Run backend business logic

D. Replace databases in microservices

Solution

1. Step 1: Understand the role of API gateways

   API gateways act as a control point for requests between clients and microservices, managing traffic and security.

2. Step 2: Compare options with gateway functions

   Storing data, running business logic, or replacing databases are not typical gateway roles.

3. Final Answer:

   Control and protect communication between services -> Option A

4. Quick Check:

   Gateway role = Control communication [OK]

Hint: Gateways manage traffic and security, not data storage [OK]

Common Mistakes:

• Confusing gateways with databases
• Thinking gateways run business logic
• Assuming gateways store data

2. Which syntax correctly defines a route in Kong's configuration to forward requests to a service?

easy

A. routes:\n - name example-route\n path: '/example'\n service: example-service

B. routes:\n - name: example-route\n paths: ['/example']\n service: example-service

C. routes:\n - name: example-route\n paths: '/example'\n service: example-service

D. routes:\n - example-route:\n paths: ['/example']\n service: example-service

Solution

1. Step 1: Review Kong route syntax

   Kong routes use a list with keys: name, paths (as a list), and service.

2. Step 2: Identify correct YAML structure

   routes:\n - name: example-route\n paths: ['/example']\n service: example-service correctly uses a list with dash, keys with colons, and paths as a list.

3. Final Answer:

   routes:\n - name: example-route\n paths: ['/example']\n service: example-service -> Option B

4. Quick Check:

   Kong route syntax = routes:\n - name: example-route\n paths: ['/example']\n service: example-service [OK]

Hint: YAML lists need dashes and keys with colons [OK]

Common Mistakes:

• Missing colon after keys
• Using string instead of list for paths
• Incorrect indentation or dash placement

3. Given this Nginx configuration snippet, what happens when a client requests /api/users?

location /api/ {
  proxy_pass http://backend-service/;
}

medium

A. The request is forwarded to http://backend-service/users

B. The request returns a 404 error

C. The request is blocked by Nginx

D. The request is forwarded to http://backend-service/api/users

Solution

1. Step 1: Understand Nginx proxy_pass behavior with trailing slash

   When proxy_pass URL ends with a slash, Nginx replaces the matching location prefix with the proxy URL path.

2. Step 2: Apply to given example

   Location prefix is /api/, proxy_pass is http://backend-service/, so /api/ is replaced by /, forwarding /users to backend-service.

3. Final Answer:

   The request is forwarded to http://backend-service/users -> Option A

4. Quick Check:

   Trailing slash in proxy_pass removes location prefix [OK]

Hint: Trailing slash in proxy_pass removes location prefix [OK]

Common Mistakes:

• Assuming full path is appended
• Confusing proxy_pass with or without trailing slash
• Thinking request is blocked or 404

4. You configured AWS API Gateway with a resource path /items and a GET method, but requests to /items return 403 Forbidden. What is the most likely cause?

medium

A. The backend service URL is incorrect

B. The API Gateway does not support GET methods

C. The GET method is not deployed or enabled in the stage

D. The client IP is blocked by AWS firewall

Solution

1. Step 1: Check AWS API Gateway method deployment

   Methods must be deployed and enabled in the stage to accept requests.

2. Step 2: Understand 403 Forbidden meaning in API Gateway

   403 often means method exists but is not authorized or deployed, not backend URL or IP block.

3. Final Answer:

   The GET method is not deployed or enabled in the stage -> Option C

4. Quick Check:

   403 = method not deployed/enabled [OK]

Hint: Deploy methods in stage to avoid 403 errors [OK]

Common Mistakes:

• Assuming backend URL causes 403
• Thinking API Gateway disallows GET
• Blaming client IP blocking without evidence

5. You want to use Kong to route requests to two microservices: serviceA at /serviceA and serviceB at /serviceB. Which configuration approach ensures correct routing and avoids path conflicts?

hard

A. Create two routes with the same path ['/service'] for both services

B. Create one route with path ['/'] forwarding to both services

C. Use a single route with no path and rely on backend to differentiate

D. Create two routes with paths ['/serviceA'] and ['/serviceB'], each linked to their respective services

Solution

1. Step 1: Understand routing by path in Kong

   Kong routes requests based on path prefixes to the correct service.

2. Step 2: Avoid path conflicts by using distinct paths

   Separate paths like '/serviceA' and '/serviceB' ensure requests go to the right service without overlap.

3. Final Answer:

   Create two routes with paths ['/serviceA'] and ['/serviceB'], each linked to their respective services -> Option D

4. Quick Check:

   Distinct paths = correct routing [OK]

Hint: Use unique paths per service to avoid conflicts [OK]

Common Mistakes:

• Using same path for multiple services
• Relying on backend to route without gateway paths
• Using root path for all services