As you know, your device or service is automatically notified if it goes down. However, you may not be aware that you can schedule certain functions to run automatically. For example, you could have the service restored without needing to do anything. Alertra monitor service supports this feature using a callbackURL.
What is a Callback URL? Unsurprisingly, the callback URL is exactly what it claims to be in a field that is filled with confusing and complex terms. CALLBACK is a method of computer programming that transmits executable code from one function to another. It is a powerful technique that allows for totally dynamic behavior. That means it can perform different tasks with the same computer program code. It is called a callback URL on the internet as it “calls back” an address, rather than just a little code.
Here’s an example that shows how a callback works. It’s something that most people who have ever bought online have probably seen. Once you have made your purchase on your favourite website, you click the “Submit” button. It’s possible that you’ll be directed to an external payment service (like PayPal), where you confirm your purchase or simply wait while the word “processing …” blinks on the screen.
After you complete the transaction, you will be taken back to the original shopping site. The callback URL is the page you see. Even though you didn’t know it, your favorite online shop’s website was being processed, and the site you visited returned it to you. You should see the page requested by the store after you have placed an order. It may be a thankyou or other page with order information, next steps, and/or their home page. It can vary depending upon what you ordered as well as when and how you ordered it.
A callback URL provides directions to an outside system for where to go next. Anything could be found at this URL. It doesn’t have to be a static address. It can be a script which performs specific functions. Alertra has pre-scripted instructions for detecting outages. You can also be notified via SMS and email if necessary. The script can be as simple and straightforward as recording the event into an external system log. It could also include stopping and restarting services that were down.
Alertra included this feature in order to make it easier for their customers to develop and maintain their systems.
This article has detailed information about the parameters to be used and includes a sample code. Check out these Alertra feature articles, as well as examples and instructions on how to use them.
Plugin “Callback URL”, which allows unlimited number rules, is available. The user can enable or disable each rule.
The fields that are required for each rule must be filled in:
The remote address of your callback code is defined by the ‘URL” field
To verify your Callback URL configuration, you can use the “Test URL” button. SMSEagle can make a callback to verify that the remote server has received it with the test parameters.
You can choose whether you want to call back to your URL with HTTP(S), POST, or HTTP(S), GET.
“Send request only” means that the request is sent whenever the sender belongs to a specific Phonebook group/contact and/or the incoming message contains a certain character string.
Optionally, you can also define “API keys of your service” values. This value will then be passed to the callback URL via parameter ‘apikey. You can leave the field empty and the parameter ‘apikey’ will not be passed on to your callback URL
User can also choose whether or not to enable self-signed SSL certificate support
SMSEagle will receive a 200 [OK] response when you send HTTP(S), GET/POST requests to your callback URL. SMSEagle can continue to retry your callback URL for up to 24 hours, if no response or any other request is received.