Comments regarding the usability of NFS volumes

[chrisbecke]

Summary

nfs mounted local volumes are a somewhat necessary way to manage persistent data on docker in swarm mode when more than one node is in play.

My issues

In using the Portainer GUI I have encountered the following issues:

1. Docker vs Agent: I went to great effort to setup a CA and create a secured access to the docker API thinking it was equivalent. Portainer did not do a good job of tellimg me that "volumes" related functionality was really really broken in this mode. It would be better to just hide the volumes management entirely so newbs like me don't accidentally try and use it.

2. Even when the Agent is installed, the Volumes panel now makes me create each volume multiple times, once on each node. If I am creating an NFS volume it is so that a workload can be scheduled on any node and find the correct volume mapped in.

3. On the Create Service & Create Container screens, when selecting a volume, the volume was listed multiple times as I had created it on multiple servers.

Possible remediations

• When managing a swarm using docker api endpoints, perhaps the portainer manager can be configured with all the swarm endpoints when it needs to manage non swarm resources like volumes.

• Otherwise volumes & containers etc need to be hidden by default in swarm mode / have an obvious banner in swarm mode when there is no agent making clear which nodes will receive updates and which wont.

• When selecting which nodes to deploy a volume to, there should be a "all nodes" filter and/or a "all nodes that match label" so that nfs volumes can be provisioned on nodes the same way their workloads will.

• When creating a container, the list of available volumes should be filtered to the node the container is being scheduled on.

• when creating a service, the list of available volumes should likewise be filtered to remove duplicates

• volumes on different nodes with the same name should be rolled up into one line in the volumes list and/or there should be a function to check and synchronize their settings if they are different.

Even better would be a system where

• nfs volumes could be assigned a label.
• An nfs volume with a label can be assigned to multiple nodes, but is treated in the portainer UI as a single volume.
• When deployed, the label is assigned to the node.
• When assigned to a service, the label is also made a deployment condition.