No need to be discouraged. Docker is just a set of tools. You can still use docker to create images, but you dont need docker to use those images in a container. K8s is using industry standard containerd. https://kubernetes.io/blog/2020/12/02/dont-panic-kubernetes-and-docker/
John Larsen On Mon, Jun 28, 2021 at 2:22 PM Eric Robinson <eric.robin...@psmnv.com> wrote: > Guido, > > I think you intended that message for me, not Brian. Thanks much for the > feedback. I have been reading about Kubernetes, but I got discouraged when > I saw that they dropped Docker support, since Docker seems to be the most > popular containeriziation technology. Also, most of the Kubernetes > tutorials I saw on YouTube seem to approach it as a dev platform, and we're > not developers. > > -Eric > > > > -----Original Message----- > > From: Guido Jäkel <g.jae...@dnb.de> > > Sent: Monday, June 28, 2021 2:43 PM > > To: Brian Wolfe <wolfebrian2...@gmail.com> > > Cc: Tomcat Users List <us...@tomcat.apachre.org> > > Subject: Re: 500 instances of tomcat on the same server > > > > Dear Brian, > > > > please take the time to read about Linux Kernel namespaces as the > technical > > base of containers. It's like two viewpoints to one thing. Take the > network > > namespace as an example: From the conceptual point of view it looks like > > you have N indipended, functional identical "IP Stacks". But from the > > technical point of view, it's just the "well known" single instance just > with an > > additional field at all items that need this (packets, routing tables, > ...) to take > > a tag value that identify the namespace instance. > > > > You may use namespaces with the raw tools like enterns or with LXC or > > Dockers. During runtime of a started container, there's nothing more you > > have to trust but the kernel because for the basics, there's no need of > > additional userland processes to keep a container running. > > > > To run an application in a "container", you start it with a bunch of > instances of > > this namespaces, at least the process namespace. You'll probably take the > > same name for the technical namespace instances - from the conceptual > > point of view this is the name of the container. > > > > Most will start something like the init binary located in a directory > tree of a > > small Linux distribution userland. This may "boot" common services and > the > > result may act like an "indipended platfrom". But you may also launch > just > > single high-level applications like a JVM running a Tomcat. > > > > That's very close to your architecture, but much more easy to handle. > For the > > network stack e.g. you may use the same ports for listeners and have the > full > > range of ports available for connections in each namespace. There are > > different ways available to route the traffic, but in any case you may > use > > individual IPs in each namespace. > > > > greetings > > > > Guido > > > > On 2021-06-28 19:22, Brian Wolfe wrote: > > > Generally, I'd agree too. We are considering using containers, but I'm > > > not yet sure what that buys us in terms of stability. > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > > For additional commands, e-mail: users-h...@tomcat.apache.org > > Disclaimer : This email and any files transmitted with it are confidential > and intended solely for intended recipients. If you are not the named > addressee you should not disseminate, distribute, copy or alter this email. > Any views or opinions presented in this email are solely those of the > author and might not represent those of Physician Select Management. > Warning: Although Physician Select Management has taken reasonable > precautions to ensure no viruses are present in this email, the company > cannot accept responsibility for any loss or damage arising from the use of > this email or attachments. >
