Cloud and Cloud Native - 2 different things

Harish Agrawal — Wed, 17 Feb 2021 10:12:06 +0000

Image Reference: https://www.mime.asia/standards-for-cloud-native-engineering-what-it-is-and-how-to-ace-it/

Often, I see folks get confused between Cloud and Cloud-Native. Or not even realise that these are different. Few years back, if you had asked me, I would be one such person.

Cloud to me, back then, meant a very simple thing.
It is virtualisation of infrastructure but with billing and automation support.

I did not know "Cloud-Native" existed. But, it does.
With the advent of containerisation (made popular by Docker) , followed by Container Orchestration (thanks to Kubernetes), cloud-native got born.
And now everything CNCF has/does, is meant for the "Cloud-Native" space.

It basically meant, for the s/w developer or any language programmer, that to run their application on cloud in an effective manner, they would need to know containers and orchestration.
Without these additional technologies and frameworks, the true benefit of cloud (aka virtualisation, pay per use and maximising the infrastructure utilisation) could not be realised.

So, "cloud-native", in short, is the set of technologies that help applications/micro-services leverage cloud.
And "Cloud" is what public companies like Amazon, Microsoft and Google provide (AWS, GCP, Azure) or may be your company provides internally for private consumption. Nothing but packaged infrastructure, in an easy to consume manner.

Docker running inside a VM, how do I access?

Harish Agrawal — Fri, 26 Jun 2020 01:34:38 +0000

Have you ever struggled to get Docker running on your local host?
Only to realize that once you have it all figured out, the actual scenario requires you to repeat the exercise but now inside a virtual machine (possibly running a Linux flavor).

Or what if docker daemon was best running at only one place instead of two?

I want to share a small learning around the docker daemon start options and how to leverage it for our benefit.

How to "run inside a Linux VM"?

Start docker daemon to listen on multiple sockets (TCP as well as Unix)

Edit the Docker service configuration

/etc/systemd/system/docker.service.d/override.conf

sudo systemctl edit docker [Service] ExecStart= ExecStart=/usr/bin/docker daemon -H tcp://0.0.0.0:50000 -H unix:///var/run/docker.sock

Reload the changed configuration

sudo systemctl daemon-reload

Verify the changed configuration

sudo systemctl cat docker | grep ExecStart OR sudo systemctl show --property=ExecStart docker

Restart Docker Daemon Service (using systemctl or service)

sudo systemctl restart docker OR sudo service docker stop sudo service docker start

Check the docker daemon logs or process to verify TCP binding

sudo systemctl status docker OR ps faux | grep docker

Finally, access docker on the host using DOCKER_HOST

Assume your VM host alias name is "myVMHostAlias"

export DOCKER_HOST=myVMHostAlias:50000 docker images

Tried the above, but its not working

If the above fails to achieve the end-objective, then you can always stop the dockerd service and start one manually
sudo service docker stop sudo /usr/bin/dockerd -H tcp://0.0.0.0:5000 -H unix:///var/run/docker.sock >> /tmp/dockerd.log 2>&1 &

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