API routing with location blocks in Nginx - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the response for a request to /api/v1/users?

Given the following nginx configuration, what will be the response status code when a client requests /api/v1/users?

Nginx

server {
  listen 80;
  location /api/ {
    return 200 "API root";
  }
  location /api/v1/ {
    return 404;
  }
}

A 502 Bad Gateway

B 200 with body 'API root'

C 404 Not Found

D 301 Moved Permanently

💡 Hint

Nginx chooses the most specific matching location block.

The request path /api/v1/users matches both /api/ and /api/v1/ location blocks. Nginx selects the longest prefix match, which is /api/v1/. This block returns 404.

❓ Configuration

intermediate

Which location block correctly proxies /api/v2/ requests?

You want to proxy all requests starting with /api/v2/ to http://backend:8080. Which location block configuration achieves this correctly?

A

location /api/v2/ {
  proxy_pass http://backend:8080;
}

B

location /api/v2/ {
  proxy_pass http://backend:8080/;
}

C

location /api/v2 {
  proxy_pass http://backend:8080/;
}

D

location /api/v2 {
  proxy_pass http://backend:8080;
}

💡 Hint

Trailing slash in proxy_pass affects URI rewriting.

Using proxy_pass http://backend:8080/; inside a prefix location with trailing slash rewrites the URI correctly by replacing the matching part. Option B is correct to proxy /api/v2/ requests properly.

❓ Troubleshoot

advanced

Why does /api/v1/data return 404 despite correct backend?

Given this nginx config, requests to /api/v1/data return 404. What is the likely cause?

Nginx

server {
  listen 80;
  location /api/ {
    proxy_pass http://backend:8080/api/;
  }
  location /api/v1/ {
    proxy_pass http://backend:8080/v1/;
  }
}

A proxy_pass URIs cause double /api/v1/ in backend request, leading to 404

B The proxy_pass in /api/v1/ should not have a trailing slash

C The /api/v1/ location is overridden by /api/ because it appears first

D Nginx does not support nested location blocks

💡 Hint

Check how proxy_pass rewrites the URI with trailing slashes.

The /api/v1/ location proxies to http://backend:8080/v1/, but the request URI /api/v1/data is appended, resulting in http://backend:8080/v1/data. However, the backend expects /v1/data without the /api/v1 prefix. The mismatch causes 404.

🔀 Workflow

advanced

Order the steps to add a new API version routing in nginx

Arrange the steps to add routing for /api/v3/ that proxies to http://backend:9090/v3/.

A 1,3,2,4

B 1,3,4,2

C 3,1,4,2

D 1,4,3,2

💡 Hint

You must reload nginx before testing changes.

First add the location block (1), then configure proxy_pass (3), reload nginx to apply (2), and finally test the routing (4).

✅ Best Practice

expert

Which configuration best avoids overlapping location conflicts?

You have multiple API versions: /api/v1/, /api/v2/, and a generic /api/. Which nginx config best avoids conflicts and ensures correct routing?

A

location /api/ {
  proxy_pass http://backend/api/;
}
location /api/v1/ {
  proxy_pass http://backend/v1/;
}
location /api/v2/ {
  proxy_pass http://backend/v2/;
}

B

location /api/v1/ {
  proxy_pass http://backend/v1/;
}
location /api/v2/ {
  proxy_pass http://backend/v2/;
}
location /api/ {
  proxy_pass http://backend/api/;
  rewrite ^/api/(.*)$ /api/v1/$1 break;
}

C

location /api/v1/ {
  proxy_pass http://backend/v1/;
}
location /api/v2/ {
  proxy_pass http://backend/v2/;
}
location = /api/ {
  proxy_pass http://backend/api/;
}

D

location ^~ /api/v1/ {
  proxy_pass http://backend/v1/;
}
location ^~ /api/v2/ {
  proxy_pass http://backend/v2/;
}
location /api/ {
  proxy_pass http://backend/api/;
}

💡 Hint

Use ^~ to prioritize prefix matches over regex or generic locations.

Using ^~ tells nginx to stop searching when a prefix match is found, avoiding conflicts between /api/v1/, /api/v2/, and /api/. This ensures specific versions route correctly before the generic /api/.