I've a local Docker Desktop installation with local images for Redis, Elastic Search, MySQL etc. I want to move from Docker Desktop to Rancher Desktop. How can I configure Rancher Desktop to use already existing docker containers, images and volumes?
Is it even possible?
Related
I have a windows service within a Docker container that needs to access a MySQL database in a Linux container on the same machine (dev machine currently).
I thought of creating an overlay network on the two "nodes" on the same machine but this isn't possible as creating the swarm worker fails on windows after creating the swarm master on linux.
Is this possible, if not what is the easiest way of doing this? The purpose of the windows container is simply to deploy to a test environment to gather data. Do I need to deploy the linux to the cloud or another machine maybe, so the windows container can communicate?
You can simply use docker compose, it will create the network automatically. Replace the MySQL host with the MySQL service name you defined in the compose yaml file. Detailed information please refer to docker-compose.
I have an application which consists of 2 docker containers. Both are small and need to interact with each other quite often through rest api.
How can I deploy both of them to a single Virtial Machine in Google Cloud?
Usually, when creating virtual machine, I get to chose a container image to deploy: Deploy a container image to this VM instance.
I can specify one of my images and get it running in the VM. Can I set multiple images?
You can not deploy multiple containers per VM.
Please consider this limitation when deploying containers on VMs:
1.You can only deploy one container for each VM instance. Consider Google Kubernetes Engine if you need to deploy multiple containers per
VM instance.
2.You can only deploy containers from a public repository or from a private repository at Container Registry. Other private repositories
are currently not supported.
3.You can't map a VM instance's ports to the container's ports (Docker's -p option).
4.You can only use Container-Optimized OS images with this deployment method. You can only use this feature through the Google Cloud
Platform Console or the gcloud command-line tool, not the API.
You can use docker-compose to deploy multi-container applications.
To achieve this on Google Cloud, you'll need:
ssh access to VM
docker and docker compose installed on the VM
I deploy a docker container on compute engine.
I want to re-deploy this docker container after I build a new docker image with same image name and tag, like webapp:latest
For now, I re-deploy docker container by restart compute engine instance.
I think it's not correct.
What is the correct way for re-deploying a docker container?
When you deploy Docker images on Google Compute Engine virtual machine instances there is some limitation as you can only deploy one container for each VM instance and you can only use Container-Optimized OS images with this deployment method.
I believe the best workaround is to uncheckbox the container option in your instance details to do not deploy a container to the VM instance by using a container-optimized OS image. This option is useful if you want to deploy a single container on the VM.
Instead, install docker in your VM outside the GCP. Also, Consider Kubernetes Engine if you need to deploy multiple containers per VM instance.
My application is comprised of two separate docker containers. One being a Grails based web application and second being a RESTful Python Flask application. Both docker containers are sitting on my local computer. They are not hosted on docker hub. They are proprietary and I don't want to host them publicly.
I would like to try Cloud Foundry to deploy these docker containers and see how it works. However, from the documentation I get a sense that Cloud Foundry doesn't support deploying docker containers sitting on a local machine.
Question
Is there a way to deploy docker containers sitting on a local computer to CloudFoundry? If not, what is a way to securely host the containers somewhere from CF can fetch them?
Is CloudFoundry capable of running a docker container that is a Python Flask application?
One option you have is to not use Docker images, and just push your code directly, one of the nice features of CF. PCF comes with a python buildpack which should automatically detect your Flask app.
Another option would be run your own trusted docker registry, push your images there, and then when you push your app, tell it to grab the images from your registry. If you google "cloud foundry docker registry" you get the following useful results you should check out:
https://github.com/cloudfoundry-community/docker-registry-boshrelease
http://docs.pivotal.io/pivotalcf/1-8/adminguide/docker.html#caveats
https://docs.pivotal.io/pivotalcf/1-7/opsguide/docker-registry.html
Looking at Rancher, what is the performance like? I guess my main question, is everything deployed in Rancher docker in docker? After reading http://jpetazzo.github.io/2015/09/03/do-not-use-docker-in-docker-for-ci/ I trying to stay away from that idea. It looks like the Rancher CI pipeline with Docker/Jenkins is docker in docker, but what about the rest? If i setup a docker-compose or deploy something from their catalog, is it all docker in docker? I've read through their documentation and this simple question has still just flown over my head. Any guidance would be much appreciated.
Thank you
Rancher itself is not deployed with Docker in Docker (DinD). The main components of Rancher, rancher/server and rancher/agent are both normal containers. The server, in a normal deployment, runs the orchestration piece and a few other key services for the catalog, Docker Machine provisioning, websocket-proxy and MySQL. All of these can be broken out if desired, but for simplicity of getting started, its all in one. We use s6 to manage the orchestration and database processes.
The rancher/agent container is privileged and requires the user to bind mount the hosts Docker socket. We package a Docker binary in the container and use it to communicate with the host on startup. It is similar to the way a Mac talks to Boot2docker, the binary is just a client talking to a remote Docker daemon. Once the agent is bootstrapped, it communicates back to the Rancher server container over a websocket connection. When containers and stacks are deployed Rancher server sends events to the agents which then call the hosts Docker daemon for deployment. The deployed containers are running as normal Docker containers on the host, just as if the user typed docker run .... In fact, a neat feature of Rancher is that if you do type docker run ... on the host, the resulting container will show up in the Rancher UI.
The Jenkins entry in the Rancher catalog, when using the Swarm plugin is doing a host bind mount of the Docker socket as well. We have some early experiments that used DinD to test out some concepts with Jenkins, but those were not released.