SKILL.md

name	docker-context-management
description	Manage Docker contexts for multi-host and remote Docker engine workflows
standards-version	1.6.3

Docker Context Management

Manage Docker contexts to connect to remote Docker hosts, switch between environments (dev/staging/prod), and orchestrate multi-host workflows.

Workflow Diagram

flowchart TD
    A[Check active context] -->|docker_contextShow| B{Need different host?}
    B -->|No| C[Use current context]
    B -->|Yes| D{Context exists?}
    D -->|Yes| E[Switch context]
    D -->|No| F[Create context]
    F -->|ssh:// or tcp://| E
    E -->|docker_contextUse| G[Verify connection]
    G -->|docker_systemInfo| H{Connected?}
    H -->|Yes| I[Run commands on remote host]
    H -->|No| J[Check credentials / firewall]
    J --> F
    I --> K[Switch back to default when done]

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Trigger

Activate when the user:

• Asks about connecting to a remote Docker host
• Wants to manage multiple Docker environments
• Needs to set up SSH or TLS-based Docker access
• Asks about switching between Docker contexts
• Mentions "docker context", "remote Docker", or "multi-host"

Required Inputs

• Task type: create, list, switch, inspect, or remove contexts
• Connection details (for create): endpoint URI (ssh:// or tcp://), credentials if applicable

Workflow

1. Assess current state - Use docker_contextShow to check the active context and docker_contextLs to see all configured contexts.
2. Identify the target - Determine which remote host or environment the user needs to connect to.
3. Create or switch - Use docker_contextCreate to add a new context or docker_contextUse to switch to an existing one.
4. Verify connectivity - After switching, run docker_systemInfo or docker_listContainers to confirm the connection works.
5. Clean up - Remove unused contexts with docker_contextRm to keep the configuration tidy.

Key References

• Docker CLI: docker context create, docker context ls, docker context inspect, docker context use, docker context show, docker context rm
• Docker endpoint formats: ssh://user@hostname, tcp://hostname:2376, unix:///var/run/docker.sock
• TLS verification: requires ca.pem, cert.pem, key.pem in ~/.docker/contexts/

Example Interaction

User: "I need to deploy to our staging server at staging.example.com"

Assistant: First, let me check your current Docker contexts.

• Calls docker_contextLs to list existing contexts
• If no staging context exists, calls docker_contextCreate with ssh://deploy@staging.example.com
• Calls docker_contextUse to switch to the new staging context
• Calls docker_systemInfo to verify the connection
• Proceeds with deployment commands targeting the remote host

MCP Usage

Tool	When to Use
docker_contextCreate	Setting up a new remote Docker host connection
docker_contextLs	Listing all configured contexts and their endpoints
docker_contextInspect	Viewing detailed context configuration (TLS certs, endpoint)
docker_contextRm	Removing outdated or unused contexts
docker_contextUse	Switching the active Docker context
docker_contextShow	Checking which context is currently active
docker_login	Authenticating to a registry on the remote host
docker_logout	Logging out from a registry

Common Pitfalls

1. SSH key not configured - ssh:// contexts require key-based auth or ssh-agent. Password prompts will hang in non-interactive MCP calls.
2. TLS certificate mismatch - When using tcp:// with TLS, ensure the host certificate matches the endpoint hostname.
3. Forgetting to switch back - After deploying to a remote context, switch back to default to avoid accidentally running commands on the remote host.
4. Context in use - Cannot remove the active context. Switch to another context first with docker_contextUse.
5. Firewall blocking - TCP endpoints (port 2376) require the port to be open. SSH endpoints (port 22) are typically more accessible.

See Also

• docker-security skill - for TLS and credential best practices
• docker-ci-cd skill - for using contexts in CI/CD pipelines
• docker-secrets rule - ensure registry credentials are not hardcoded