‫Let's see is there any well known wait and containerized a legacy VM based monolithic app and make it
‫cloud native.
‫And how do you redirect the incoming consumer request from the VM to those containers.
‫So this is a very loaded question and
‫going to make this the last question.
‫So because everyone else is taking my questions and I'm running out of time so this is a long topic
‫and it's a great topic.
‫Basically what you're asking here is we read the question again Is there any well known way to containerized
‫a legacy VM based on monolithic applications and make it clone native.
‫And how do you redirect the incoming consumer requests from VM to those containers.
‫So that is two separate questions.
‫I would do the I'm going to answer the first one first to containerized a legacy VM Docker provides.
‫If you're an enterprise customer they provide a certain level of tools depending on what the app is
‫and it's very framework specific because you know obviously a python app has certain requirements certain
‫dependencies you cannot containerized a full VM that's not a thing because a VM includes the kernel
‫and the kernel drivers and all sorts of things that don't go in containers so you wouldn't wouldn't
‫want to containerized the rest of the OS anyway because that's probably at least a gig of unnecessary
‫stuff inside that VM right.
‫If you don't know if it's a Windows machine it's probably 10 gig of unnecessary stuff so you wouldn't
‫want to do that either but it's not that hard to containerized a legacy app because surely somewhere
‫you have some written documentation or even just screenshots of how you installed that.
‫And as long as you have that basic information you can recreate that in a docker file and really a docker
‫file is just like an automated way of installing something on Linux or Windows.
‫And so if you have those instructions you can do that.
‫And there are tools at Docker they kind of sell them with Docker enterprise.
‫You can basically go back to Docker con twenty eighteen in San Francisco from a year ago.
‫You can look that up on YouTube and they demo some of these tools in their keynote speech where they
‫talk about taking legacy web apps mostly especially on Windows side because those can be like Dot Net
‫framework apps and stuff like that.
‫And then finding all of the parts and pieces to them based on their own package files that come with
‫those apps right.
‫I use these apps have their own package installation tooling and they look at those files and then find
‫all the right pieces and put it in.
‫But I don't know of a tool that I would recommend that is going to just look at the entire operating
‫system and then suck it all in into one container.
‫So I would say look at the information on how that app is installed or even just basically if you don't
‫even have that.
‫Just start looking at you know just start trying with a docker file and you can work on and iterate
‫to get to the point that you actually have it working in the container.
‫Now if you're dealing with the data moving the data around is a separate conversation.
‫You've got to get that data into a volume first.
‫And so that's that's going to be a separate process.
‫I would first first focus on getting the app working then I would worry as a sort of a sub project on
‫how to move the data over if that's indeed a problem where you have unique data inside that old VM.
‫And then thirdly how do you redirect it incoming consumer requests from the VM to those containers that
‫is going to be completely dependent upon your infrastructure.
‫And that is really not a whole lot to do with containers.
‫That has to do with is this a web request.
‫Is there a front end proxy in front of it like an elastic load balancer or a application load balancer
‫or your own third party F5 proxy.
‫Is it is it not a web app.
‫If it's not a web app then you've got to look at how do those connections come in.
‫Because Docker is not going to do that for you Docker doesn't do connection.
‫You know redirect from an old VM that's not a thing that containers or container orchestration solves
‫that that I've ever seen at least.
‫So that's really three parts of a major project.
‫And so when you hire a consultant to help you migrate this is kind of what I do migrate old applications
‫into containers Docker has an entire part of their company dedicated to this.
‫They call it the MTA program migrating traditional apps and they basically send out Tiger Teams to companies
‫for a fee and they'll spend a week on site.
‫I think it is and they'll take your app migrate it and you'll learn everything about it.
‫How help you essentially migrated into a container or copy it in a container get it running get the
‫data moved over and then swap the connections in your case if you don't have any sort of front end load
‫balancing you've got to have basically you've got to have that app running in the container and then
‫figure out a downtime you know it could be just minutes where you're going to redirect the DNS traffic
‫or whatever you need to get that flipped over and that has nothing to do with containers and everything
‫to do with just routing and DNS and networking that basically the same process you would do for moving
‫from an old VM to a new VM when you have to replace VMS over time but that's the Cliff Notes on essentially
‫what it's like to be a docker consultant because you're always migrating old apps and the new stuff
‫for other people and helping them do that.