Earlier I had written a blog post about kubernetes and containers, but as days passed I had to get accustomed to my new job life and hence I thought of giving a month to get habituated to this new routine. Over this month I realised that I should now make my schedule in such a way where I have to keep progressing my about Kubernetes at the same time. Hence, after a month of observation that docker is also same as Kubernetes but where docker runs on a single cluster Kubernetes runs on a cluster. While I started learning Kubernetes because I had no idea how these tools are used I got very bored and eventually the interest died. But I wanted know about containers and how people are using them, so I started from again, smaller steps but longer run.
Dockers are also containerized environment where one can pull an image and their dependencies and libraries. It helps in solving the compatibility issue of different applications with respect to OS, libraries and dependencies. But in Linux kernel one can run only Linux containers that is one can run Linux softwares having different flavors of OS but one cannot run windows container on Linux kernel.
The difference between containers and virtual machines is that a Virtual machine consists of hypervisor and on top of sits different Virtual machines which has their own operating system and hypervisors which makes the system heavy due to high storage capacity. It also takes up minutes to boot up whereas Dockers on the other hand just sits on top of OS and creates different environments a.k.a containers and the application can have it’s own libraries and dependencies plus it takes less storage capacity compared to VM. Containers are less isolated that Virtual Machines as they rely on same OS or kernel. One can pull down any required image from docker hub which is a public registry.
The difference between Image and containers is that an image is a package or a template which is used to create containers and the containers are running image instances that are isolated and have their own environments.