cURL errors are a common stumbling block for developers, and one such error, “cURL error 3,” often leads to head-scratching moments. The cURL error 3, as indicated in the Laravel logs (local.INFO: cURL error 3), signifies a problem during the execution of a cURL request. More specifically, it points to issues related to network connectivity, DNS resolution, or accessibility of the specified URL.

1. Misconfigured URL:
   • The URL specified in the cURL request may be incorrect or improperly formatted.
2. DNS Resolution Problems:
   • Issues with resolving the domain name specified in the URL.
3. Network Connectivity Issues:
   • Problems with internet connectivity or restrictions, such as firewalls, preventing the cURL request.

In my case:

Upon investigation, it was discovered that the root cause of the cURL error 3 in this scenario was a configuration oversight. Specifically, the necessary configuration parameters were not defined in the config/app.php file of the Laravel application.

Here’s the snippet of the missing configuration:

'DOCTORS_M_MANAGEMENT_BASE_URL' => env('DOCTORS_M_MANAGEMENT_BASE_URL', 'not found in .env file'),
'DOCTORS_OAUTH_TOKEN_URL' => env('DOCTORS_OAUTH_TOKEN_URL', 'not found in .env file'),
'DOCTORS_GRANT_TYPE' => env('DOCTORS_GRANT_TYPE', 'not found in .env file'),
'DOCTORS_CLIENT_ID' => env('DOCTORS_CLIENT_ID', 'not found in .env file'),
'DOCTORS_CLIENT_SECRET' => env('DOCTORS_CLIENT_SECRET', 'not found in .env file'),
'DOCTORS_CREATE_DOCTOR_USER' => env('DOCTORS_CREATE_DOCTOR_USER', 'not found in .env file'),

This simple addition enabled the application to read the required values from the .env file, preventing the cURL error 3 from occurring.