Category Archives: Virtualization

Docker PaaS and Resources

I found about this public Trello board which offers curated list of Docker PaaS systems (public, private), deployment tools, and many other related resources.

During last couple of years, I have tried most of Docker PaaS (private self-hosted) for development and some production load (microservices).

I have enjoyed using following, and continue to use them for various things (development, production):

I hope to share my experiences, and examples (projects, services — running in production) soon.

Docker Awesome

I love these *-awesome projects on Github.

The Docker Awesome is all about Docker and it’s ecosystem. Hundreds of curated links help you understand Docker, and it’s fast growing ecosystem.

If you think something is missing there, go ahead and add to or send a PR to

BTW! There is another awesome project which curates links of all other awesome projects: :-)

Docker: Second Birthday

Docker is one of the hottest technologies; I started with it’s first release not too long back, however, in Docker world it feels like Docker has been around for a long time.

What a paradigm shift we have witnessed: a few technologies get that kind of attention, momentum, growth, and community in such a short time (24 months).

Today, we use Docker to develop, test, ship, integrate, deploy, and run apps/services. Docker has solved developer (devops) usability problems; it’s hard to go back and do things without Docker.

Haven’t heard of Docker, or didn’t find time to try it out? Start with following links.

What’s new with Docker? Look at following links:

  • Docker Compose (docker-compose, formerly known as fig)

    Compose is a tool for defining and running complex applications with Docker. With Compose, you define a multi-container application in a single file, then spin your application up in a single command which does everything that needs to be done to get it running.

  • Docker Machine (docker-machine)

    Machine makes it really easy to create Docker hosts on your computer, on cloud providers and inside your own datacenter. It creates servers, installs Docker on them, then configures the Docker client to talk to them.

  • Docker Swarm (swarm)

    Docker Swarm is native clustering for Docker. It turns a pool of Docker hosts into a single, virtual host.Swarm serves the standard Docker API, so any tool which already communicates with a Docker daemon can use Swarm to transparently scale to multiple hosts: Dokku, Compose, Krane, Flynn, Deis, DockerUI, Shipyard, Drone, Jenkins… and, of course, the Docker client itself.

Virtualization with VMware vSphere (ESXi) Hypervisor

One of our servers, collocated in our office, crashed couple of weeks back. We took this opportunity to virtualize most of the stuff, earlier only some intances were virtualized.

Installing and setting up VMware vSphere Hypervisor is a straight forward process, even the process of creating virtual-machines.

Most of time, I spent was figuring out:

  • Storage devices and configuration
  • How many virtual machines, do we need?
  • Which operating systems, do we need?
  • Network configuration

I am not going to cover details of installation and network configuration. I might write more posts in future to cover specifics. Meanwhile, I would love to answer the comments, if I know or share anything I know.

Anyway, this is what we have now:

  • IBM x3250 M2
    • Intel Xeon (Quadcore) x64
    • 4 GB memory
    • 3TB+ storage connected to LSI RAID and SATA controller
  • Host: VMware vSphere Hypervisor – which runs out of  1.5 TB datastore, directly connected to SATA controller (different from LSI)
  • Guest VMs:
    • OpenVPN Access Server for VPN
    • Ubuntu 10.10 Server as Development sandbox
    • Zentyal(eBox) as Internet Gateway (filtering, IDs, proxy)
    • Ubuntu 10.04 LTS Server for SVN, Mails, Local Staging WebServer
    • Windows 2008 Server for ActiveDirectory, FileServer, Windows-Specific-Software (access-control-management-gui, etc.)
    • Others: Project Specific VMs

We are very happy with the improved performance and stability, and the way hardware is properly used. Thanks to VM templates, clones and snapshots, we would be able to provision above infrastructure with minimal downtime.

I would soon replace Windows Server with Zentyal (eBox), which I believe, can handle most of things. However, we would need another Windows XP box to run some software (proprietary), which only runs on windows, to manage various other devices (EPBX, Access-Control-System, etc.).

We now have relatively more scalable infrastructure, more virtual machines can be created to take care of email-server, svn-server, etc.

We are yet to invest in a sophisticated storage device such as DAS or NAS or SAN, hence we are relying on some cheap tricks here:

  • 1.5 TB disk as datastore for VMware vSphere, which stores
    • Guest Operating System VMs
    • Guest Operating System VMs Paging files
    • Virtual Disks (non critical data – programs and configs) required by host virtual-machines
  • 1.5 TB disk via Raw Device Mapping (RDM) shared among virtual machines
  • 500 GB disk via Raw Device Mapping (RDM) shared among virtual machines
  • 1.5 TB USB/Firewire – Backup storage
    • Rsync is used to backup critical data and configs from all virtual machines on daily, weekly and monthly basis.

Things I didn’t like:

  • VMware vSphere client requires Microsoft Windows
  • VMware vSphere client doesn’t allow creating RDMs from GUI, one has to use these instructions

Finally, I could execute some of things I planned more than two years back.