Introduction

What is Democratic-CSI?

Democratic-CSI implements the csi (Container Storage Interface) specifications
providing storage for various container orchestration systems (ie: Kubernetes, Nomad, OpenShift).

The current focus is providing storage via iSCSI or NFS from ZFS-based storage systems, predominantly TrueNAS / FreeNAS and ZoL on Ubuntu.

The current drivers implement the depth and breadth of the csi specifications, so you
have access to resizing, snapshots, clones, etc functionality.

What can Democratic-CSI offer?

Several implementations of CSI drivers
▶️ freenas-nfs (manages zfs datasets to share over nfs)
    » freenas-iscsi (manages zfs zvols to share over iscsi)
    » freenas-smb (manages zfs datasets to share over smb)
    » freenas-api-nfs experimental use with SCALE only (manages zfs datasets to share over nfs)
    » freenas-api-iscsi experimental use with SCALE only (manages zfs zvols to share over iscsi)
    » freenas-api-smb experimental use with SCALE only (manages zfs datasets to share over smb)
    » zfs-generic-nfs (works with any ZoL installation...ie: Ubuntu)
    » zfs-generic-iscsi (works with any ZoL installation...ie: Ubuntu)
    » zfs-local-ephemeral-inline (provisions node-local zfs datasets)
    » synology-iscsi experimental (manages volumes to share over iscsi)
    » lustre-client (crudely provisions storage using a shared lustre share/directory for all volumes)
    » nfs-client (crudely provisions storage using a shared nfs share/directory for all volumes)
    » smb-client (crudely provisions storage using a shared smb share/directory for all volumes)
    » node-manual (allows connecting to manually created smb, nfs, lustre, and iscsi volumes, see sample PVs in the
       examples directory)

Development
    » Framework for developing CSI drivers

If you have any interest in providing a CSI driver, simply open an issue to discuss. The project provides an extensive framework to build and making it relatively easy to implement new drivers.

Community Guides

• https://jonathangazeley.com/2021/01/05/using-truenas-to-provide-persistent-storage-for-kubernetes/
• https://gist.github.com/admun/4372899f20421a947b7544e5fc9f9117 (migrating from nfs-client-provisioner to democratic-CSI)
• https://gist.github.com/deefdragon/d58a4210622ff64088bd62a5d8a4e8cc (migrating between storage classes using velero)

Installation

Predominantly 3 prerequisites are needed:

• Nodes preperation (ie: Kubernetes cluster nodes)
• Storage server preperation
• Deployment of the driver into the cluster (helm chart provided with sample values.yaml)

Node preperation

Alright, you have chosen your driver. Let's start by configuring the prerequisites for your Node.
You can choose to use either NFS or iSCSI or both.

NFS configuration

RHEL / CentOS

sudo yum install -y nfs-utils

Ubuntu / Debian

sudo apt-get install -y nfs-common

iSCSI configuration

RHEL / CentOS
Install the following system packages

sudo yum install -y lsscsi iscsi-initiator-utils sg3_utils device-mapper-multipath

Enable multipathing

sudo mpathconf --enable --with_multipathd y

Ensure that iscsid and multipathd are running

sudo systemctl enable iscsid multipathd && sudo systemctl start iscsid multipathd

Start and enable iscsi

sudo systemctl enable iscsi && sudo systemctl start iscsi

Ubuntu / Debian
Install the following system packages

sudo apt-get install -y open-iscsi lsscsi sg3-utils multipath-tools scsitools

  Multipathing
  Multipath is supported for the iSCSI-based drivers. Simply setup   multipath to your liking and set multiple
  portals in the config as appropriate.

  NOTE: If you are running Kubernetes with Rancher/RKE please see the following:
  Support host iscsi simultaneously with kubelet iscsi (pvc)

  Add the mutlipath configuration

sudo tee /etc/multipath.conf <<-'EOF'
defaults {
    user_friendly_names yes
    find_multipaths yes
}
EOF

  Enable the multipath-tools service and restart to load the configuration

sudo systemctl enable multipath-tools && sudo service multipath-tools restart

  Ensure that open-iscsi and multipath-tools are enabled and running

sudo systemctl status multipath-tools
sudo systemctl enable open-iscsi.service
sudo service open-iscsi start
sudo systemctl status open-iscsi

FreeNAS-SMB

If using with Windows based machines you may need to enable guest access (even if you are connecting with credentials)

Set-ItemProperty HKLM:\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters AllowInsecureGuestAuth -Value 1 ; Restart-Service LanmanWorkstation -Force

ZFS-local-ephemeral-inline

This driver provisions node-local ephemeral storage on a per-pod basis. Each node should have an identically named zfs pool created and avaialble to the driver.
NOTE: this is NOT the same thing as using the docker zfs storage driver (although the same pool could be used). No other requirements are necessary.

• Pod Inline Volume Support

Server preperation

Server preparation depends slightly on which driver you are using. The recommended version of FreeNAS is 12.0-U2 or higher, however the driver should work with much older versions as well.

TrueNAS / FreeNAS (freenas-nfs, freenas-iscsi, freenas-smb, freenas-api-nfs, freenas-api-iscsi, freenas-api-smb)

API usage without SSH
The various freenas-api-* drivers are currently EXPERIMENTAL and can only be used with SCALE 21.08+. Fundamentally these drivers remove the need for ssh connections and do all operations entirely with the TrueNAS api. With that in mind, any ssh/shell/etc requirements below can be safely ignored. Also note the following known issues:

• Additional middleware changes to support Democratic CSI use of native API
• TrueNAS Scale 21.08 - Could not log into all portals
• Pure api based truenas driver (ssh dependency removed)

API with the usage of SSH
Ensure the following services are configurged and running:

  » SSH

• if you use a password for authentication make sure it is allowed
• Ensure ZSH, BASH, or SH is set as the root shell, CSH gives false errors due to quoting

NFS configuration

  » NFS

iSCSI configuration

  » iSCSI NOTE: (fixed in 12.0-U2+) when using the FreeNAS API concurrently the /etc/ctl.conf file on the server can become invalid, some sample scripts are provided in the contrib directory to clean things up ie: copy the script to the server and directly and run - ./ctld-config-watchdog-db.sh | logger -t ctld-config-watchdog-db.sh & please read the scripts and set the variables as appropriate for your server.

• ensure you have pre-emptively created portals, initatior groups, auths
  • make note of the respective IDs (the true ID may not reflect what is visible in the UI)
  • IDs can be visible by clicking the the Edit link and finding the ID in the browser address bar
  • Optionally you may use the following to retrieve appropiate IDs:
    • curl --header "Accept: application/json" --user root:<password> 'http(s)://<ip>/api/v2.0/iscsi/portal'
    • curl --header "Accept: application/json" --user root:<password> 'http(s)://<ip>/api/v2.0/iscsi/initiator'
    • curl --header "Accept: application/json" --user root:<password> 'http(s)://<ip>/api/v2.0/iscsi/auth'
• SMB

If you would prefer you can configure Democratic-CSI to use a non-root user when connecting to the FreeNAS server:

• Create a non-root user (e.g., CSI)

• Ensure that user has passwordless sudo privileges:

  csi-username ALL=(ALL) NOPASSWD:ALL
  
  # if on CORE 12.0-u3+ you should be able to do the following
  # which will ensure it does not get reset during reboots etc
  # at the command prompt
  cli
  
  # after you enter the truenas cli and are at that prompt
  account user query select=id,username,uid,sudo_nopasswd
  
  # find the `id` of the user you want to update (note, this is distinct from the `uid`)
  account user update id=<id> sudo=true
  account user update id=<id> sudo_nopasswd=true
  # optional if you want to disable password
  #account user update id=<id> password_disabled=true
  
  # exit cli by hitting ctrl-d
  
  # confirm sudoers file is appropriate
  cat /usr/local/etc/sudoers
  

  (note this can get reset by FreeNAS if you alter the user via the GUI later)

• Instruct Democratic-CSI to use sudo by adding the following to your driver configuration:

  zfs:
    cli:
      sudoEnabled: true
  

Starting with TrueNAS CORE 12 it is also possible to use an apiKey instead of the root password for the http connection.

Issues to review:

• https://jira.ixsystems.com/browse/NAS-108519
• https://jira.ixsystems.com/browse/NAS-108520
• https://jira.ixsystems.com/browse/NAS-108521
• https://jira.ixsystems.com/browse/NAS-108522
• https://jira.ixsystems.com/browse/NAS-107219

ZoL (zfs-generic-nfs, zfs-generic-iscsi)

Ensure ssh and zfs is installed on the nfs/iscsi server and that you have installed targetcli.

• sudo yum install targetcli -y
• sudo apt-get -y install targetcli-fb

Synology (synology-iscsi)

Ensure iscsi manager has been installed and is generally setup/configured.

Helm Installation

helm repo add democratic-csi https://democratic-csi.github.io/charts/
helm repo update
# helm v2
helm search democratic-csi/

# helm v3
helm search repo democratic-csi/

# copy proper values file from https://github.com/democratic-csi/charts/tree/master/stable/democratic-csi/examples
# edit as appropriate
# examples are from helm v2, alter as appropriate for v3

# add --create-namespace for helm v3
helm upgrade \
--install \
--values freenas-iscsi.yaml \
--namespace democratic-csi \
zfs-iscsi democratic-csi/democratic-csi

helm upgrade \
--install \
--values freenas-nfs.yaml \
--namespace democratic-csi \
zfs-nfs democratic-csi/democratic-csi

A note on non standard kubelet paths

Some distrobutions, such as minikube and microk8s use a non-standard kubelet path. In such cases it is necessary to provide a new kubelet host path, microk8s example below:

microk8s helm upgrade \
  --install \
  --values freenas-nfs.yaml \
  --set node.kubeletHostPath="/var/snap/microk8s/common/var/lib/kubelet"  \
  --namespace democratic-csi \
  zfs-nfs democratic-csi/democratic-csi

• microk8s - /var/snap/microk8s/common/var/lib/kubelet
• pivotal - /var/vcap/data/kubelet

openshift

Democratic-CSI generally works fine with openshift. Some special parameters need to be set with helm (support added in chart version 0.6.1):

# for sure required
--set node.rbac.openshift.privileged=true
--set node.driver.localtimeHostPath=false

# unlikely, but in special circumstances may be required
--set controller.rbac.openshift.privileged=true

Nomad

democratic-csi works with Nomad in a functioning but limted capacity. See the Nomad docs for details.

Multiple Deployments

You may install multiple deployments of each/any driver. It requires the following:

• Use a new helm release name for each deployment
• Make sure you have a unique csiDriver.name in the values file
• Use unqiue names for your storage classes (per cluster)
• Use a unique parent dataset (ie: don't try to use the same parent across deployments or clusters)

Snapshot Support

Install beta (v1.17+) CRDs (one per cluster):

• https://github.com/kubernetes-csi/external-snapshotter/tree/master/client/config/crd

kubectl apply -f snapshot.storage.k8s.io_volumesnapshotclasses.yaml
kubectl apply -f snapshot.storage.k8s.io_volumesnapshotcontents.yaml
kubectl apply -f snapshot.storage.k8s.io_volumesnapshots.yaml

Install snapshot controller (once per cluster):

• https://github.com/kubernetes-csi/external-snapshotter/tree/master/deploy/kubernetes/snapshot-controller

# replace namespace references to your liking
kubectl apply -f rbac-snapshot-controller.yaml
kubectl apply -f setup-snapshot-controller.yaml

Install Democratic-CSI as usual with volumeSnapshotClasses defined as appropriate.

• https://kubernetes.io/docs/concepts/storage/volume-snapshots/
• https://github.com/kubernetes-csi/external-snapshotter#usage
• https://github.com/democratic-csi/democratic-csi/issues/129#issuecomment-961489810

Migrating from freenas-provisioner and freenas-iscsi-provisioner

It is possible to migrate all volumes from the non-csi freenas provisioners to Democratic-CSI.

Copy the contrib/freenas-provisioner-to-democratic-csi.sh script from the project to your workstation, read the script in detail, and edit the variables to your needs to start migrating!

Sponsors

A special shout out to the wonderful sponsors of the project!

Related

• https://github.com/nmaupu/freenas-provisioner
• https://github.com/travisghansen/freenas-iscsi-provisioner
• https://datamattsson.tumblr.com/post/624751011659202560/welcome-truenas-core-container-storage-provider
• https://github.com/dravanet/truenas-csi
• https://github.com/SynologyOpenSource/synology-csi