I want to start practicing with k8s for the CKAD exam. I run on ubuntu 18.04.
I noticed everywhere that I need to download Virtualbox for minikube. I believe that VB is needed in case I don't start my cluster with a driver but if I use the Docker driver when I start my cluster shouldn't that be enough? Is microk8s a better option?
It seems that the preferred way is use --driver=docker driver instead of --driver=none for minikube, although it is technically not baremetal as it is significantly easier to configure and does not require root access. The ‘none’ driver is recommended for advanced users only. (info below from https://minikube.sigs.k8s.io/docs/drivers/docker/)
docker
Overview
The Docker driver allows you to install Kubernetes into an existing Docker install. On Linux, this does not require virtualization to be enabled.
Requirements
Install Docker 18.09 or higher
amd64 or arm64 system.
Usage
Start a cluster using the docker driver:
minikube start --driver=docker
To make docker the default driver:
minikube config set driver docker
Yes you can. Check here.
Minikube also supports a --driver=none option that runs the Kubernetes components on the host and not in a VM. Using this driver requires Docker and a Linux environment but not a hypervisor.
Jus run
$ minikube start
Caution: If you use the none driver, some Kubernetes components run as privileged containers that have side effects outside of the Minikube environment. Those side effects mean that the none driver is not recommended for personal workstations
Related
I am running a vagrant box using virtual box (running headless ubuntu 18.04) on windows 10 host machine.
Inside the virtual box, I have minikube set up using docker as the vm-driver
minikube start --memory=6144 --cpus=2 --disk-size=40g --vm-driver=docker --bootstrapper kubeadm --kubernetes-version=1.17.4
My application is exposed via an ingress to the ubuntu machine running inside virtual box and I am able to access the application via wget/cURL
On running minikube IP it gave me the IP of the docker container in which minikube runs
Some additional configuration info -
Vagrant file -
I would like to access the application from my windows machine's browser , any idea how to achieve that ? vagrant port forwarding doesn't seem to help.
If you really want to use a setup like this(using vagrant etc.). You can just use --vm-driver=none and let the kubernetes run in your ubuntu box directly, this way you can leverage port-forwarding. You probably also can do it your way but I've never tried so I wouldn't know, but I know that none works. You can follow this guide.
There are different options like running minikube on windows directly. Which is perfectly fine as well.
I am exploring and learning about containers and kubernetes using podman and minikube on a linux workstation. I use podman to build images on the workstation and would like to deploy these images in minikube also running on the workstation using the kvm2 virtual machine driver. I also start minikube using the CRI-O container runtime.
What are efficient workflows to deploy these images from the workstation to minikube in this scenario? Docker is not running on the minikube VM so the reusing the Docker daemon as described in the minikube documentation is not an option. Sharing the host file system with minikube also appears to not be viable at this time when using kvm2.
Is running a local registry that is visible to both the workstation and the minikube vm the best option? Answers to How to use local docker images with Minikube? and (Kubernetes + Minikube) can't get docker image from local registry appear to offer good solutions for configuring a local registry.
Would skopeo be a solution?
Edit: this is a nice post describing how to set up a registry using podman: https://computingforgeeks.com/create-docker-container-registry-with-podman-letsencrypt/
thank you
Brad
Minikube documentation provides the foundation for a potential workflow at https://minikube.sigs.k8s.io/docs/tasks/docker_registry/. In order to use podman in lieu of docker I did the following
Start minikube, as instructed, with the --insecure-registry flag. I specifically use
minikube start --network-plugin=cni --enable-default-cni --bootstrapper=kubeadm --container-runtime=cri-o --cpus 4 --memory 4g --insecure-registry "192.168.39.0/24"
Enable the minikube registry addon.
minikube addons enable registry
Configure podman to use the insecure minikube registry by adding the registry to the insecure registries section of /etc/containers/registries.conf. This section now looks like
[registries.insecure]
registries = ['192.168.39.175:5000']
where 192.168.39.175 is the minikube ip. This ip may change following minikube restarts.
Follow the build, push and run commands in https://minikube.sigs.k8s.io/docs/tasks/docker_registry/ substituting podman for docker. This assumes the test-img container file exists.
Build: podman build --tag $(minikube ip):5000/test-img .
Push: podman push $(minikube ip):5000/test-img
Run: kubectl run test-img --image=$(minikube ip):5000/test-img
This worked but suffers from a serious complication: there is no apparent way at this time to set the IP address for the minikube VM when using kvm2. The IP will always be in the 192.168.39.0/24 subnet but that is the only certainty. Each time minikube is started the IP address of the registry will change which has significant implications for podman and the workflow in general.
More to come an another solution.
I do have an Ubuntu VM in VirtualBox on Windows 10. If i follow the instructions to install Minikube I get a start error:
> minikube start &
[1] 4297
vagrant#ubuntu-xenial:~$ o minikube v0.35.0 on linux (amd64)
> Creating virtualbox VM (CPUs=2, Memory=2048MB, Disk=20000MB) ...
# Downloading Minikube ISO ...
184.42 MB / 184.42 MB [============================================] 100.00%
0s
! Unable to start VM: create: precreate: VBoxManage not found. Make sure
VirtualBox is installed and VBoxManage is in the path
Does it mean i need to install VirtualBox in the Ubuntu VM too? Kind of VB inside VB..
thanks
I'd recommend to install Minikube on your host OS (Windows) and use the already installed Virtual box as a hypervisor provider.
If for any reason you want to launch it on Ubuntu VM, there are two options:
I. Minikube supports a --vm-driver=none option that runs the Kubernetes components on the host and not in a VM. Using this driver requires Docker and a Linux environment, but not a hypervisor. In this case you have to provide an address to you local API server
`minikube start --vm-driver=none --apiserver-ips 127.0.0.1 --apiserver-name localhost`
And then go and edit ~/.kube/config, replacing the server IP that was
detected from the main network interface with "localhost". For example:
apiVersion: v1
clusters:
- cluster:
certificate-authority-data:/home/asuh/.minikube/ca.crt
server: https://localhost:8443
name: minikube
II. Install VM Ware on Windows and run Ubuntu within installed Virtualbox
and and enabled VT-X/AMD-v in outer VM.
Regarding the error you have at the moment:
However now i get another error like: /usr/local/bin/minikube: cannot
execute binary file
Make sure you have installed a proper version of Minikube. For your Ubuntu VM it should be
curl -Lo minikube https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64 \
&& chmod +x minikube
It is not recommended to use VM inside VM to run minikube. Check this answer. Try to run minikube with no vm drivers.
minikube start --vm-driver=none
I have read on minikube issues, but can not find it right now.
HTH
from this example. DockerOperator has the docker_url parameter which is "URL of the host running the docker daemon.".
But when i run in Kubernetes engine on Google Cloud Platform, how can i find this docker_url on Kubernetes?
You can run the following command to find out the docker url:
$docker-machine url [docker_machine_name]
Docker machine is not installed on the container images by default. You will have to install docker-machine manually by following these steps.
You will also have to use the Ubuntu image if you would like this functionality. I tried to install docker machine using a cos image, and it does not work since the image does not have the necessary dependencies.
I'm wondering how can install a package inside the minikube VM. I need some tools.
I have tried the /bin/toolbox container, but It does not have internet conexion.
[root#docker-fedora-24 ~]# dnf update --verbose
cachedir: /var/cache/dnf
DNF version: 1.1.9
Cannot download 'https://mirrors.fedoraproject.org/metalink?repo=updates-released-f24&arch=x86_64': Cannot prepare internal mirrorlist: Curl error (6): Couldn't resolve host name for https://mirrors.fedoraproject.org/metalink?repo=updates-released-f24&arch=x86_64 [Could not resolve host: mirrors.fedoraproject.org].
Error: Failed to synchronize cache for repo 'updates'
I have tried the same toolbox script in my computer and it is properly working.
What configuration parameters I'm missing in minikube or systemd-nspaw?
Or how can I cook a customized minikube VM?
Thanks a lot
You can run minicube without VM on your local docker (if you use linux):
minikube start --vm-driver=none
A alternative, run toolbox with docker run --net=host ... to make network for container more transparent. Troubleshoot your internet connection with nslookup, traceroute/tracepath, curl -v, ifconfig.
http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:Ch04:_Simple_Network_Troubleshooting#.WfY1xGi0OUk
Minikube is not meant to be tweaked. The advised method is to prepare a helm chart for your application. As part of the helm chart you can add whatever tool you need in your docker file... Including make... Then you can install or upgrade your package in kubernetes/minikube using helm.
I had a similar problem when I wanted to use tcpdump in the minikube VM.
I ended up using minikube mount SRC-dir:DST-dir to mount the host folder inside the VM and copying the tcpdump binary along with dependent libs (libcrypto and libpcap) to the mount point.
Then I executed tcpdump from the minikube VM and it worked.
Note: My host arch and the minikube VM arch (x86_64) was the same.
Note also: export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:DST-dir has to be done.