I am trying to use Kubernetes and Jenkins for my deployment of micro services developed using Spring Boot. When I am exploring many YouTube videos and other documentation tutorials are using dockerhub.com as keeping published image as repository.
Can I deploy docker image in Kubernetes by using Jenkins docker image build without using this dockerhub.com ? Means I don't want to share client code in a public place. So can I use Jenkins without dockerhub.com?
You do need to use some registry- kubernetes needs a registry URL to be able to pull and instantiate a particular image as a container in a pod. To avoid having the images themselves be publicly accessible you have 2 options:
use a business account at a public registry. You can get one of these from Docker, or from other services like Google or Quay. When you push images using a business account, you get a private space in the public registry and only your account credentials can push and pull those images. In this case your Kubernetes- and your Jenkins- has to be configured with credentials derived from your account to be able to pull those private images into your cluster.
run a private registry in your cluster or on your non-cluster infrastructure There are many flavors of private registries, including Docker's, Atlassian's, and many others. This keeps your images entirely on your infrastructure. The tradeoff is that you have to configure and run this as a production service, and most private registries suitable for production use have a lot of moving parts for scalable image storage, indexing, backup, and so forth.
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Why would someone use a private docker registry when they could just share their dockerfile's in source control and have docker image consumers build directly from the dockerfile with docker build?
To my untrained eye the private docker registry seems to serve the same purpose as source control except it adds complexity because it's been decoupled from the branch of code that you're in and so you (or your CI/CD server more to the point) has to reconstruct which tag to pull.
When you deploy on real machines (say you have a job that deploys on 10 machines), usually you don't really want to rebuild the image over and over again.
Instead you can build image once, store it somewhere (???) then maybe deploy on test environment, run some tests, make sure its a good image indeed (starts, tests pass, etc) and then deploy on production.
So this "somewhere" means that you should have some registry, and if you don't want to use docker hub - you can use private docker registry.
This makes sense from both security (don't publish on cloud if you don't need to)
and performance (moving images between servers in private network is faster).
If you're running kubernetes you can also configure it to pull the images from the docker registry and run pods based on these images as specified in the kubernetes deployment files.
If you're running on AWS you can use docker registry to run services like Fargate or ECS. They will take care of scaling out across machines (pretty much like k8s does) but they still need to take the images from somewhere, well, its a private registry (in this case in the cloud called ECS - Elasctic Container Registry).
Bottom line, in many (simple) cases you can live without it, but in some other cases it comes pretty handy
We are building a proprietary Java application based on Docker. Right now, we are using local docker installation and development is in progress. When we want to share this application, hope this should be deployed in some docker registry. Docker registry is free and opensource? or how can I securely+freely allow my customers to access my application?.Basically, we want zero cost secure deployment option using docker.
If you're fine with putting your docker images public - you can use the docker hub.
If you want to keep it private - you can opt for one of the free private registries, e.g. treescale
See a longer list of free private registries here
with a new release of our product, we want to move to new technologies(kubernetes) so that we can take advantage of it services. we have a local kubernetes application running in our infra. we have made our applicatons dockerize and now we want to use the images to integrate it with kubernetes to make cluster --pods,
but we are stuck with docker registry as our customer do not want to have any public/private docker repository(registry) where we can upload this images. we have try with (docker save and docker load) but no luck(error: portal-66d9f557bb-dc6kq 0/1 ImagePullBackOff) Is it at all possible to have some filesystem where from we can access this images or any other alternative is welcome if that solves our problems(no private/public repository/registry).
A Docker registry of some sort is all but a requirement to run Kubernetes. Paid Docker Hub supports private images; Google and Amazon both have hosted registry products (GCR and ECR respectively); there are third-party registries; or you can deploy the official registry image locally.
There's an alternative path where you docker save every private image you reference in any Kubernetes pod spec, then docker load it on every single node. This has obvious scale and maintenance problems (whenever anybody updates any image you need to redeploy it by hand to every node). But if you really need to try this, make sure your pod specs specify ImagePullPolicy: Never to avoid trying to fetch things from registries. (If something isn't present on a node the pod will just fail to start up.)
The registry is "just" an open-source (Go) HTTP REST service that implements the Docker registry API, if that helps your deployment story.
I have a docker image in a private docker hub repository. I have created a Google Cloud instance template for load balancing and on-demand instantiation of compute instances. What is the right way to automatically pull the repo on my newly created instances?
The only solution I can come up with is to put my docker login password in the startup script for the instance template. Is that the right approach?
GitHub has deploy keys, which allow me to put the private key in my instance for read only access, which seems like a better strategy, but I can't find anything like that for pulling a docker repo.
What is currently the recommended way to mirror a Private Docker Registry?
Mirroring functionality is provided by official docker-registry image but only for the Public Registry.
See documentation:
"Beware that mirroring only works for the public registry. You can not create a mirror for a private registry."
My use-case:
A bigger development team that is working in an office with a limited network. They only pull docker images from registries. Pushing is occasional and handled by Jenkins box hosted in AWS. Most of the images they use resides in our password protected Private Registry (served over https). So it's only natural to mirror/cache the Registry on a machine in a local network. If not for https I would just go for HTTP_PROXY and local squid install.
I'm sure I'm not the only one solving docker dev bandwidth problem. What do you do?
It is now possible to do this with the "proxy" settings in the configuration for a V2 registry. Just put up another registry (on a different server/port from any other private registry you have) and on every docker engine, set the '--registry-mirror' flag to point to it.
Just watch out for accidental pushes - always retag your images to the private registry or a private repository if you wish to keep them private.
Right now, I would recommend using the (new) golang registry (https://github.com/docker/distribution) instead of the (v1) python one, and go with the proxy solution (using HTTP_PROXY + a reverse proxy cache - squid, or whatever else pleases your tastes - I would probably use varnish).
Native support for "mirroring" built into the registry itself will come eventually, and later more flexible transports.