Docker Context¶

Docker context lets Docker commands on the development host target a remote VeeaHub Docker daemon.

Show Contexts¶

Run:

docker context ls

On a fresh Docker install, the only context is usually default:

NAME        DESCRIPTION                               DOCKER ENDPOINT
default *   Current DOCKER_HOST based configuration   unix:///var/run/docker.sock

Create a VeeaHub Context¶

First confirm the hub is configured:

vhc2 hub config show

Create the context:

vhc2 hub access --hub-id vh-2341 context create

Expected output:

Success! Docker Context(vh-2341) Created
Please reboot your VeeaHub to update Dockerd Configuration

Reboot the VeeaHub:

vhc2 hub access --hub-id vh-2341 reboot

Validate the context:

vhc2 hub access --hub-id vh-2341 context validate

Expected output:

Context (vh-2341) working OK

List contexts again:

docker context ls

The VeeaHub context should appear beside default:

NAME        DESCRIPTION                               DOCKER ENDPOINT
default *   Current DOCKER_HOST based configuration   unix:///var/run/docker.sock
vh-2341                                               tcp://192.168.1.36:2376

Use a Default Context¶

Set the active Docker context:

docker context use vh-2341
docker node ls

Return to local Docker:

docker context use default

Use a Dynamic Context¶

Prefer dynamic context in examples and scripts:

DOCKER_CONTEXT=vh-2341 docker node ls

With the required API version:

DOCKER_API_VERSION=1.39 DOCKER_CONTEXT=vh-2341 docker node ls

This runs only that command against vh-2341. Later commands continue to use the default context.

Expected output for a mesh shows Swarm nodes and the manager:

ID                            HOSTNAME              STATUS   AVAILABILITY   MANAGER
3ee1vv4eezf33r7q0y0oftskq     E09BCW00C0B000000519  Ready    Active
nq62rqtirly5r2l6nnglr1nza     E09BCWE0C0B000000594  Ready    Active
slveb02jifizf4fezib88lioj *   E10CTWE080C000002341  Ready    Active         Leader

Recommended Pattern¶

Use dynamic context for examples, scripts, and destructive commands:

DOCKER_API_VERSION=1.39 DOCKER_CONTEXT=vh-2341 docker ps

This is more verbose, but it makes the target explicit every time.

Use docker context use <context> only when you are doing a focused interactive session and can see the active context in your prompt.

Optional Prompt Helper¶

If you often switch contexts, add a prompt helper so the active context is visible.

Create ~/docker-escape-prompt:

#!/bin/sh
ctx=$(docker context show)
if [ "$ctx" = "default" ]
then
  echo "\033[01;37m[Docker context:${ctx}]"
else
  echo "\033[01;31m[Docker context:${ctx}]"
fi

Make it executable:

chmod a+x ~/docker-escape-prompt

Add this to ~/.bashrc:

PS1="\$($HOME/docker-escape-prompt)\n$PS1"

To revert to a normal prompt:

PS1='\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '