[v2.1] Docker Agent - Template System Integration

[JoshuaAFerguson]

Epic: v2.1 Docker Agent Development
Component: Docker Agent - Template System
Assignee: Builder (Agent 2)
Milestone: v2.1
Estimated Effort: 8-12 hours

Overview

Enable Docker Agent to parse templates and create Docker containers from StreamSpace templates.

Requirements

Template Parsing

• Fetch templates from Control Plane API
• Parse template manifest (YAML/JSON)
• Convert template to Docker container configuration
• Support template variables and substitution
• Cache templates locally

Template Structure

Reuse existing template format from K8s agent:

apiVersion: streamspace.io/v1alpha1
kind: Template
metadata:
  name: firefox-browser
spec:
  displayName: "Firefox Browser"
  description: "Mozilla Firefox web browser"
  image: linuxserver/firefox:latest
  vnc:
    enabled: true
    port: 3000
  resources:
    memory: 512Mi
    cpu: 250m
  env:
    - name: DISPLAY
      value: ":1"
  volumes:
    - name: home
      mountPath: /config
      persistent: true

Docker Conversion

Template → Docker Container:

// Parse template
template := parseTemplate(templateYAML)

// Convert to Docker config
containerConfig := &container.Config{
    Image: template.Spec.Image,
    Env: convertEnvVars(template.Spec.Env),
    ExposedPorts: convertPorts(template.Spec.VNC),
}

hostConfig := &container.HostConfig{
    Resources: container.Resources{
        Memory: convertMemory(template.Spec.Resources.Memory),
        NanoCPUs: convertCPU(template.Spec.Resources.CPU),
    },
    Binds: convertVolumes(template.Spec.Volumes, sessionID),
}

Resource Mapping

Template	Docker
resources.memory: 512Mi	Resources.Memory: 536870912 (bytes)
resources.cpu: 250m	Resources.NanoCPUs: 250000000
volumes	Docker volumes or bind mounts
env	Container environment variables

Files to Create/Update

agents/docker-agent/
└── pkg/
    └── docker/
        ├── template.go       # Template parsing
        ├── converter.go      # Template → Docker config
        └── resources.go      # Resource conversion

Testing Checklist

• Parse K8s-style templates successfully
• Convert templates to Docker config correctly
• Memory limits applied correctly
• CPU limits applied correctly
• Environment variables passed to container
• VNC port configuration correct
• Volumes created and mounted
• Multiple templates supported
• Template caching works
• Invalid templates handled gracefully

Template Examples to Support

1. firefox-browser - GUI browser with VNC
2. vscode - VS Code IDE with VNC
3. ubuntu-desktop - Full Ubuntu desktop
4. chrome - Chromium browser

Success Criteria

• ✅ All existing K8s templates work with Docker agent
• ✅ Resource limits enforced correctly
• ✅ VNC port configuration correct
• ✅ Persistent volumes work
• ✅ Template validation prevents invalid configs

Depends On: #151 (Docker Agent Core Implementation)
Related: K8s Agent template handling (reference implementation)