Postfix on container
 

hi all ,
am a lil noob on containers. trying to find out if running postfix on docker is a good idea. currently i hv my postfix running smoothly on rhel 7.8 vms with 30k mails daily. and there is this organization directions to move towards openshift/openstack and containers in coming months and years. thus i need to explore if putting postfix on containers is really worthwhile. seeking your advise on this. thanks team!

A virtual machine acts and behaves no differently than a physical machine. If you have postfix working now, that exact configuration will work on a VM/container. There is a certified RHEL 7.x container image, available from Red Hat...since you're using RHEL you are paying for the license/support (RIGHT??), so you can contact Red Hat and they can get you to the image. All that said, network bandwidth is a consideration...30k mails that are tiny shouldn't be an issue; 30k emails with 2 MB attachments is FAR different.

What problem are you trying to solve? Postfix, in my opinion, isn't really a good candidate for k8s. Especially if this is going to be one of the first apps your org is migrating. Whatever you decide to go with, make sure you have good persistent storage and backup/recovery/dr options.

OpenShift is Red Hat's container management platform build on top of Kubernetes running on OpenStack VMs. Thus, I will assume you mean Docker-type containers, but you may want to explain a bit more what your company's containerization strategy is about.

With the caveat that I know nothing about mail server management, allow me to point you to a commercial dockerized Postfix+Dovecot solution named mailcow (I have no relationship whatsoever with them). See also their Github repo. It's open-source, so I suppose you could try it out. In any case, this seems to be evidence that Postfix in containers makes sense.

Just trying to understand, what are some of the reasons why you wouldn't want to containerize Postfix?

I remember when virtualization came on to the scene, mail servers weren't virtualized at first, but as the technology matured, they were virtualized.