404 Not Found

How to Implement Custom Error Pages with OpenResty for 404 Not Found Errors

=====================================================================================

When setting up a new application or API, it's crucial to handle errors gracefully. One of the most common error scenarios is when users access an invalid URL, resulting in a dreaded 404 'Not Found' status code being returned by your server.

In this article, we'll explore how you can use OpenResty - a powerful open-source webserver and reverse proxy toolset based on Nginx (pronounced 'en-ks'), to serve custom error pages when such situations arise. Specifically, we're interested in setting up a robust 404 not found page that will be displayed instead of the default Nginx 404 message.

Step 1: Installing OpenResty

----------------------------

Before diving into the meat and potatoes of implementing your own 404 page using OpenResty, you'll first need to install it on your server. Fortunately, installing Openresty is relatively straightforward thanks to their excellent documentation which covers supported operating systems in great detail.

For this example let's assume that we're running a Debian/Ubuntu-based distribution such as Ubuntu Server or Amazon Linux 2 (AL2). You can refer here for installation instructions specific to other OSes: https://openresty.com/download/

Step 2: Configuring OpenResty

-----------------------------

Once you've successfully installed Openresty, the next step is to configure it to serve your custom error pages. To do this, open up the main configuration file (usually located at /etc/openresty/ngx.conf or similar depending on where you chose during installation) using a text editor like nano:

```bash

sudo nano /etc/openresty/ngx.conf

```

Now add the following code block towards the end of your `nginx` directive section:

```lua

if ($request_uri != '') then

set $msg 'Sorry, it seems that you've reached an invalid page!';

else

set $msg '';

end

error_page 404 /usr/local/openresty/htdocs/403.html;

try_files $uri @notfound;

location @notfound {

internal;

}

if ($request_method == 'GET') then

return 301 permanent https://yourdomain.com$request_uri;

else

return 405 Method Not Allowed;

end

error_page 500 502 503 504 /usr/local/openresty/htdocs/50x.html;

location = / {

index index.html main.html default.htm index.php;

}

```

Here's a brief explanation of the above configuration:

* `if ($request_uri != '') then`: This line checks if there is any URI present in the request. If yes, it proceeds to set up our custom 404 error page.

* `set $msg 'Sorry, it seems that you've reached an invalid page!'; else set $msg(''); end;` : Sets a variable called `$msg` with your desired message if no URI is found or leaves it empty otherwise.

Step 3: Creating Custom Error Pages

----------------------------------

With the OpenResty configuration in place, we now need to create our custom error pages. For this example, let's assume that you've created two HTML files named `404.html` and `50x.html` within a directory called `htdocs/`.

Here is an example of what your directory structure might look like:

```bash

/usr/local/openresty/

|__ conf.d/

|__ ngx.conf.sample

|__ htdocs/

|-- error_pages

|-- 404.html (custom 404 page)

404 Not Found

```

Step 4: Restarting OpenResty and Testing

Once you've made all the necessary changes, don't forget to restart your Openresty server for these changes to take effect:

```bash

sudo service openresty restart

```

You can now test whether everything is working as expected by accessing an invalid URL on your website. If configured correctly, you should see a custom 404 error page instead of the default Nginx message.

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In conclusion, implementing robust and customizable error pages with OpenResty for common scenarios like 404 Not Found errors can significantly improve user experience when interacting with your application or API. By following these simple steps outlined above, you'll be well on your way to serving professional-looking custom error messages that will leave a lasting impression (for all the right reasons!) on both visitors and search engines alike.

Remember always keep an eye out for updates from Openresty's official website regarding new features and security patches!

404 not found openresty