DoGaMa-serv/internal/agent/agent_plan.go

package agent

import (
	"errors"
	"fmt"
	"io/fs"
	"path"
	"reflect"
	"strings"

	"git.zaynet.fr/DoGaMa/DoGaMa-serv/internal/agentwire"
	"git.zaynet.fr/DoGaMa/DoGaMa-serv/internal/catalog"
)

// PlanPolicy independently binds privileged deployment fields to validated,
// embedded template snapshots. The agent never trusts a caller-supplied image,
// container port, mount destination or security-sensitive command by itself.
type PlanPolicy struct {
	snapshots map[string]catalog.Snapshot
	assets    fs.FS
}

func NewPlanPolicy(snapshots []catalog.Snapshot, assets fs.FS) (*PlanPolicy, error) {
	if len(snapshots) == 0 {
		return nil, errors.New("agent plan policy requires validated templates")
	}
	if assets == nil {
		return nil, errors.New("agent plan policy requires embedded assets")
	}
	policy := &PlanPolicy{snapshots: make(map[string]catalog.Snapshot, len(snapshots)), assets: assets}
	for _, snapshot := range snapshots {
		key := snapshot.Template.ID + "@" + snapshot.Template.Version
		if _, exists := policy.snapshots[key]; exists {
			return nil, errors.New("duplicate agent template snapshot")
		}
		policy.snapshots[key] = snapshot
	}
	return policy, nil
}

type ApprovedAsset struct {
	Destination string
	Content     []byte
}

func (p *PlanPolicy) Assets(plan agentwire.DeploymentPlan) ([]ApprovedAsset, error) {
	snapshot, ok := p.snapshots[plan.TemplateID+"@"+plan.TemplateVersion]
	if !ok {
		return nil, fmt.Errorf("template snapshot not registered: %s@%s", plan.TemplateID, plan.TemplateVersion)
	}
	if snapshot.Digest != plan.TemplateDigest {
		return nil, fmt.Errorf("template snapshot digest mismatch: received=%s expected=%s", plan.TemplateDigest, snapshot.Digest)
	}
	result := make([]ApprovedAsset, 0, len(snapshot.Template.Container.Assets))
	for _, asset := range snapshot.Template.Container.Assets {
		if !asset.ReadOnly {
			return nil, errors.New("writable template asset is not allowed")
		}
		content, err := fs.ReadFile(p.assets, path.Join(snapshot.AssetRoot, asset.Source))
		if err != nil {
			return nil, fmt.Errorf("read approved template asset: %w", err)
		}
		result = append(result, ApprovedAsset{Destination: asset.Destination, Content: content})
	}
	return result, nil
}

func (p *PlanPolicy) Validate(plan agentwire.DeploymentPlan) error {
	if p == nil || plan.Validate() != nil {
		return errors.New("invalid deployment plan")
	}
	snapshot, ok := p.snapshots[plan.TemplateID+"@"+plan.TemplateVersion]
	if !ok {
		return fmt.Errorf("template snapshot not registered: %s@%s", plan.TemplateID, plan.TemplateVersion)
	}
	if snapshot.Digest != plan.TemplateDigest {
		return fmt.Errorf("template snapshot digest mismatch: received=%s expected=%s", plan.TemplateDigest, snapshot.Digest)
	}
	template := snapshot.Template
	imagePrefix := template.Container.Image + ":"
	if !strings.HasPrefix(plan.Image, imagePrefix) || !reflect.DeepEqual(plan.Entrypoint, template.Container.Entrypoint) || !reflect.DeepEqual(plan.CapAdd, template.Container.Capabilities.Add) || plan.StopTimeoutSeconds != template.Container.StopTimeoutSeconds {
		return errors.New("container plan differs from template")
	}
	if len(plan.Arguments) < len(template.Container.Arguments) || !reflect.DeepEqual(plan.Arguments[:len(template.Container.Arguments)], template.Container.Arguments) || !allowedArguments(template, plan.Arguments[len(template.Container.Arguments):]) || !allowedEnvironment(template, plan.Environment) {
		return errors.New("container configuration differs from template")
	}
	if plan.Resources.CPUCores < template.Requirements.Minimum.CPUCores || plan.Resources.MemoryMB < template.Requirements.Minimum.MemoryMB || plan.Resources.StorageGB < template.Requirements.Minimum.StorageGB {
		return errors.New("container resources are below template minimum")
	}
	if len(plan.Ports) != len(template.Container.Ports) || len(plan.Mounts) != len(template.Storage.Mounts) {
		return errors.New("container plan shape differs from template")
	}
	ports := make(map[string]agentwire.PlanPort, len(plan.Ports))
	for _, port := range plan.Ports {
		ports[port.ID] = port
	}
	for _, expected := range template.Container.Ports {
		actual, ok := ports[expected.ID]
		if !ok || actual.Protocol != expected.Protocol || actual.ContainerPort != expected.ContainerPort || actual.Publish != expected.Publish {
			return errors.New("container port differs from template")
		}
	}
	mounts := make(map[string]agentwire.PlanMount, len(plan.Mounts))
	for _, mount := range plan.Mounts {
		mounts[mount.ID] = mount
	}
	for _, expected := range template.Storage.Mounts {
		actual, ok := mounts[expected.ID]
		if !ok || actual.ContainerPath != expected.ContainerPath || actual.ReadOnly != expected.ReadOnly {
			return errors.New("container mount differs from template")
		}
	}
	return nil
}

func allowedEnvironment(template catalog.Template, environment map[string]string) bool {
	allowed := map[string]bool{}
	for key := range template.Container.Environment {
		allowed[key] = true
	}
	for _, field := range template.Configuration.Fields {
		if field.Target.Kind == "environment" {
			allowed[field.Target.Name] = true
		}
	}
	for key := range environment {
		if !allowed[key] {
			return false
		}
	}
	return true
}

func allowedArguments(template catalog.Template, arguments []string) bool {
	allowed := make([]string, 0)
	for _, field := range template.Configuration.Fields {
		if field.Target.Kind == "argument" {
			allowed = append(allowed, strings.ReplaceAll(field.Target.Name, "{{value}}", ""))
		}
	}
	for _, argument := range arguments {
		ok := false
		for _, prefix := range allowed {
			if argument == prefix || strings.HasPrefix(argument, prefix+"=") || (strings.HasSuffix(prefix, "=") && strings.HasPrefix(argument, prefix)) {
				ok = true
				break
			}
		}
		if !ok {
			return false
		}
	}
	return true
}