I've read through all the docs and a few SO posts and can't find an answer to this question:
Where does minikube persist its persistent volumes in my local mac filing system?
Thanks
First of all keep in mind that Kubernetes is running on Minikube cluster. Minikube itself run on Virtual Machine, so all data would be stored in this VM not on your MacOS.
When you want to point exact place where you would like to save this data in Kubernetes you could choose between:
hostpath
A hostPath volume mounts a file or directory from the host node's filesystem into your Pod. This is not something that most Pods will need, but it offers a powerful escape hatch for some applications.
local
A local volume represents a mounted local storage device such as a disk, partition or directory.
Local volumes can only be used as a statically created PersistentVolume. Dynamic provisioning is not supported yet.
Compared to hostPath volumes, local volumes can be used in a durable and portable manner without manually scheduling Pods to nodes, as the system is aware of the volume's node constraints by looking at the node affinity on the PersistentVolume.
However, Minikube supports only hostpath.
In this case you should check Minikube documentation about Persistent Volumes
minikube supports PersistentVolumes of type hostPath out of the box. These PersistentVolumes are mapped to a directory inside the running minikube instance (usually a VM, unless you use --driver=none, --driver=docker, or --driver=podman). For more information on how this works, read the Dynamic Provisioning section below.
minikube is configured to persist files stored under the following
directories, which are made in the Minikube VM (or on your localhost
if running on bare metal). You may lose data from other directories on
reboots.
/data
/var/lib/minikube
/var/lib/docker
/tmp/hostpath_pv
/tmp/hostpath-provisioner
If you would like to mount directory from host you would need to use minikube mount.
$ minikube mount <source directory>:<target directory>
For more details, please check Minikube Mounting filesystems documentation.
If you are using the volume type hostPath the files are saved on your node.
To access your node filesystem you can use the command: minikube ssh and under your mounted path you'll find your documents.
Related
In a Kubernetes cluster on Oracle cloud, I have a pod with an Apache server.
This pod needs a persistent volume so I used a persistentVolumeClaim and the cloud provider is able to automatically create an associated volume (Oracle Block Volume).
The access mode used by the PVC is readWriteOnce and therefore the volume created has the same access mode.
Everything work great.
Now I want to backup this volume using borg backup and borgmatic by starting a new pod regularly with a cronJob.
This backup pod needs to mount the volume in read only.
Question:
Can I use the previously defined PVC?
Do I need to create a new PVC with readOnly access mode?
As per documentation:
ReadWriteOnce:
the volume can be mounted as read-write by a single node. ReadWriteOnce access mode still can allow multiple pods to access the volume when the pods are running on the same node.
That means if you make a strict rule for deploying your pods to the same node, you can use the same PVC, here's the INSTRUCTION
I have a cluster with multiple nodes and i also have created a persistent volume in order to have persistence of my data in a Pod. What i am actually looking for is the following:
Lets say that we have a pod, named pod1 that is connected with the Persistent Volume and in a specific directory we have some files. If i have another different pod, named pod2 which is in the same node with the pod1, that wants to copy a file from the directory of the pod1 which is connected with the PV.
Is there any right way to configure this?
What you need is a shared persistent volume mounted in both pods.
You can achieve this in a couple of different ways:
Use a hostPath volume pointing to the same directory.
Use a volume type that supports RWX (read write many) access mode.
When speaking about Openstack Magnum deployment of Kubernetes cluster (on bare metal nodes), is it somehow possible to leverage local disks on those nodes to act as persistent storage for containers?
In advance, thanks a lot.
Openstack Magnum uses Cinder to provision storage for kubernetes cluster. As you can read here:
In some use cases, data read/written by a container needs to persist
so that it can be accessed later. To persist the data, a Cinder volume
with a filesystem on it can be mounted on a host and be made available
to the container, then be unmounted when the container exits.
...
Kubernetes allows a previously created Cinder block to be mounted to a
pod and this is done by specifying the block ID in the pod YAML file.
When the pod is scheduled on a node, Kubernetes will interface with
Cinder to request the volume to be mounted on this node, then
Kubernetes will launch the Docker container with the proper options to
make the filesystem on the Cinder volume accessible to the container
in the pod. When the pod exits, Kubernetes will again send a request
to Cinder to unmount the volume’s filesystem, making it available to
be mounted on other nodes.
Its usage is described in this section of the documentation.
If setting up Cinder seems like too much overhead, you can use local volume type which allows to use local storage device such as a disk, partition or directory already mounted on a worker node's filesystem.
I am looking to do local dev of an app that is running in Kubernetes on minikube. I want to mount a local directory to speed up development, so I can make code changes to my app (python) without rebuilding the container.
If I understand correctly, I have two out of the box options:
9P mount which is provided by minikube
hostPath mount which comes directly from Kubernetes
What are the differences between these, and in what cases would one be appropriate over the other?
9P mount and hostPath are two different concepts. You cannot mount directory to pod using 9P mount.
9P mount is used to mount host directory into the minikube VM.
HostPath is a persistent volume which mounts a file or directory from the host node's(in your case minikube VM) filesystem into your Pod.
Take a look also on types of Persistent Volumes: pv-types-k8s.
If you want to mount a local directory to pod:
First, you need to mount your directory for example: $HOME/your/path into your minikube VM using 9P. Execute command:
$ minikube start --mount-string="$HOME/your/path:/data"
Then if you mount /data into your Pod using hostPath, you will get you local directory data into Pod.
Another solution:
Mount host's $HOME directory into minikube's /hosthome directory. Get your data:
$ ls -la /hosthome/your/path
To mount this directory, you have to just change your Pod's hostPath
hostPath:
path: /hosthome/your/path
Take a look: minikube-mount-data-into-pod.
Also you need to know that:
Minikube is configured to persist files stored under the following
directories, which are made in the Minikube VM (or on your localhost
if running on bare metal). You may lose data from other directories on
reboots.
More: note-persistence-minikube.
See driver-mounts as an alternative.
I know that Kubernetes does not support mounting GCS buckets inside a Pod. But If I use GoogleFuse to mount a GCS bucket on the Node and then expose it to a Pod as a host path will that work?
It should work. For Host Path volumes, kube doesn't enforce any policy. But if your FUSE daemon restarts, the mount will become inaccessible. AFAIK, kube does not support mount propagation for volumes.