Re: Postgresql + containerization possible use case

Thank you Rainer,
I'll have to play a little bit myself, and read some serious docs about it, in order to fully comprehend your thoughts.
I'll revisit your positions I hope.

On 13/12/21 5:11 μ.μ., Rainer Duffner wrote:
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>> Am 13.12.2021 um 12:41 schrieb Achilleas Mantzios <achill(at)matrix(dot)gatewaynet(dot)com <mailto:achill(at)matrix(dot)gatewaynet(dot)com>>:
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>> Our setup has been open source since forever. So licenses for something that used to be free for ages would be hard to introduce.
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> That ist totally understandable.
> 140x800 for the RHEL license alone is over 100k/year.
> Though you might get a volume discount at that point ;-)
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>> So Docker is NOT free? Please share your thoughts? I am a complete noob.
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> The commercial version is not free.
> The „CE“ version is free, but I’m not sure how stable the API is.
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> Dockerhub, for what it’s worth, isn’t completely free anymore either.
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>> Those servers I am talking about have no internet connectivity. And the satellite connection costs are high.
>> (although I think we pay a fixed amount for a certain total data transfer size).
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> Yes. That’s why using a more offline-friendly infrastructure might make more sense.
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> RHEL seems to be pretty well tuned running in high-secure air-gapped networks - which is what a ship basically is.
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>>> The question is: do you want to get there?
>>> But maybe your developers want to get here, because they don’t want to learn about software-packaging (anymore) - but is that what the business wants?
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>> Those servers live for years, the objective is to facilitate upgrades.
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> Yes, but docker-upgrades aren’t free either.
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> At least, I cannot imagine running such an infrastructure in the gung-ho style that a typical developer runs his docker-containers.
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> You’d want to run a tight ship with those ;-)
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> You will need a lot more tooling around this (continuous integration, continuous deployment) - which is the reason I suggested moving all this infrastructure to the ship itself. If you produce and
> mirror the artifacts locally, you should have less backhaul traffic (which is what I assume is killing you with sat-com - downstream can probably be had cheap-ish these days - or pretty soon via the
> likes of StarLink)
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>>> https://www.docker.com/blog/how-carnival-creates-customized-guest-experiences-with-docker/
>> Thanks for the link, I didn't quite understand what they do with docker (video included).
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> It’s passenger entertainment and engagement, from what I can see.
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> It’s sad and funny to read, as shortly after that huge cruises got out of fashion ;-)
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> It’s also not mission-critical.
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>> 120 docker containers in two data centers on the ship? Ours will be just a single linux box with limited connectivity (in some seas no connectivity ) to the internet/shore.
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> Yes, and this is IMO where you will have to get management on board to upgrade infrastructure and tooling around docker containers (and likely Kubernetes) - if your developers persist on using it
> that way.
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> You will end up running a small server-cluster on each ship - I would guess there are specialized vendors who produce sea-worthy server-equipment.
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>>> (That was pre-pandemic…)
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>>> I would make an educated guess that you’d need to have the whole docker-infrastructure on each ship (build-server, repository etc.pp.) to minimize sat-com traffic.
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>> Hmm, I don't know about that. The hardware is given (existing) and limited.
>> You are like the 2nd person who warned about comms as being an issue with docker/containers.
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>> Can't someone have a free docker system inside a linux server and run the containers (free again) until he/she decides to upgrade either docker or (more frequently) one of the images?
>> Is Docker upwards compatible? Meaning new Docker versions to run old images ?
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> Yes, likely. But upgrading docker itself sometimes comes with its own challenges.
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> As you said, all these servers are with limited connectivity and no local help available...
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> Again, I’m the last person you want to ask how docker actually works (but often, the developers themselves don’t know either, but they know which commands to feed it…)
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> Also, most of my knowledge of ships is from watching NCIS (and reading Clive Cussler novels...).
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>>> I mean, it looks like it could be done. But this is where the „dev“ part in the „devops" world has to take a step back and the „ops“ guys need to come forward.
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>> Can you please explain in more detail?
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> With 140-ish servers air-gapped on vessels around the world, this is IMO a serious operations-problem and needs to be handled properly, with an air-tight (or water-tight…) operational concept.
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> Your infrastructure has outgrown its original design limits. Time to talk to management about upping the game (and the budget).
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> Best Regards

--
Achilleas Mantzios
DBA, Analyst, IT Lead
IT DEPT
Dynacom Tankers Mgmt