---
id: ae43e548-58b3-4241-acf5-d128176bc70a
---

# Nginx Cross Origin Resource Sharing Error
---

This incident type refers to errors that occur when attempting to make cross-origin resource sharing (CORS) requests to an Nginx web server. CORS is a security feature implemented by web browsers to prevent unauthorized access to resources on a different domain. When Nginx is misconfigured or not configured to allow CORS requests, web browsers will block the requests, resulting in errors. This can cause issues for web applications that rely on making requests to different domains for data or resources.

### Parameters
```shell
export ORIGIN_DOMAIN="PLACEHOLDER"

export NGINX_SERVER_DOMAIN="PLACEHOLDER"

export PATH_TO_NGINX_CONFIGURATION_FILE="PLACEHOLDER"

export DOMAIN_OR_IP_ADDRESS_TO_ALLOW_CORS_REQUESTS_FROM="PLACEHOLDER"
```

## Debug

### Verify the Nginx server is running
```shell
systemctl status nginx
```

### Check the Nginx configuration files
```shell
nginx -t
```

### Check the Nginx access logs for CORS errors
```shell
grep "cross-origin" /var/log/nginx/access.log
```

### Check the Nginx error logs for CORS errors
```shell
grep "cross-origin" /var/log/nginx/error.log
```

### Verify if the correct CORS headers are present in the response
```shell
curl -I -X GET -H "Origin: ${ORIGIN_DOMAIN}" ${NGINX_SERVER_DOMAIN}
```

### Check the Nginx configuration files for CORS settings
```shell
grep -r "add_header" /etc/nginx/
```

## Repair

### Configure Nginx to allow CORS requests by adding the appropriate headers to HTTP responses. This can be done using the "add_header" directive in Nginx configuration files.
```shell


#!/bin/bash



# Define variables

NGINX_CONF_FILE=${PATH_TO_NGINX_CONFIGURATION_FILE}

CORS_ORIGIN=${DOMAIN_OR_IP_ADDRESS_TO_ALLOW_CORS_REQUESTS_FROM}



# Add CORS headers to Nginx configuration file

sed -i '/server {/a add_header Access-Control-Allow-Origin "$CORS_ORIGIN";' $NGINX_CONF_FILE



# Restart Nginx service

systemctl restart nginx


```

This incident type refers to errors that occur when attempting to make cross-origin resource sharing (CORS) requests to an Nginx web server. CORS is a security feature implemented by web browsers to prevent unauthorized access to resources on a different domain. When Nginx is misconfigured or not configured to allow CORS requests, web browsers will block the requests, resulting in errors. This can cause issues for web applications that rely on making requests to different domains for data or resources.


```shell
export ORIGIN_DOMAIN="PLACEHOLDER"

export NGINX_SERVER_DOMAIN="PLACEHOLDER"

export PATH_TO_NGINX_CONFIGURATION_FILE="PLACEHOLDER"

export DOMAIN_OR_IP_ADDRESS_TO_ALLOW_CORS_REQUESTS_FROM="PLACEHOLDER"
```


### Verify the Nginx server is running

```shell
systemctl status nginx
```

### Check the Nginx configuration files

```shell
nginx -t
```

### Check the Nginx access logs for CORS errors

```shell
grep "cross-origin" /var/log/nginx/access.log
```

### Check the Nginx error logs for CORS errors

```shell
grep "cross-origin" /var/log/nginx/error.log
```

### Verify if the correct CORS headers are present in the response

```shell
curl -I -X GET -H "Origin: ${ORIGIN_DOMAIN}" ${NGINX_SERVER_DOMAIN}
```

### Check the Nginx configuration files for CORS settings

```shell
grep -r "add_header" /etc/nginx/
```


### Configure Nginx to allow CORS requests by adding the appropriate headers to HTTP responses. This can be done using the "add\_header" directive in Nginx configuration files.

```shell


#!/bin/bash



# Define variables

NGINX_CONF_FILE=${PATH_TO_NGINX_CONFIGURATION_FILE}

CORS_ORIGIN=${DOMAIN_OR_IP_ADDRESS_TO_ALLOW_CORS_REQUESTS_FROM}



# Add CORS headers to Nginx configuration file

sed -i '/server {/a add_header Access-Control-Allow-Origin "$CORS_ORIGIN";' $NGINX_CONF_FILE



# Restart Nginx service

systemctl restart nginx


```


Nginx Cross Origin Resource Sharing Error

Overview

Parameters

Debug

Verify the Nginx server is running

Check the Nginx configuration files

Check the Nginx access logs for CORS errors

Check the Nginx error logs for CORS errors

Verify if the correct CORS headers are present in the response

Check the Nginx configuration files for CORS settings

Repair

Configure Nginx to allow CORS requests by adding the appropriate headers to HTTP responses. This can be done using the "add_header" directive in Nginx configuration files.

Learn more

Related Runbooks

Support