Introduction to Docker

Deploying applications is a complex task. You have to create some VMs, be it on DigitalOcean or AWS, download and install necessary prerequesites and then deploy your application. It would be easy if it were to end there, however, it doesn’t.

Following this you have application maintenance which includes deploying updated versions of your application in addition to other things like bug fixes. And this is where the real complexity starts. Your updated version might need another dependent application to be installed which in turn might need a version of some random tool to be upgraded. You did what was necessary but then you find out that the deployment of the updated application failed because you forgot to do that one null check in some corner of your application. So frantically you download the previous version of your application and try to restore it only to find that it doesn’t work anymore since you upgraded that random tool to support your newer application.

While all this is happening either your entire application is unavailable because your application is single instance or if it is indeed multi-instance split by a loadbalancer, all the other instances are being stressed out because one of the node is down.

And now you are thinking. Well, there has to be a better way.

Well my friend, there is.

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