emissary/internal/agent/controller/app/app_handler.go

package app

import (
	"bytes"
	"context"
	"database/sql"
	"path/filepath"
	"sync"
	"text/template"

	"forge.cadoles.com/Cadoles/emissary/internal/agent/controller/app/spec"
	appSpec "forge.cadoles.com/Cadoles/emissary/internal/agent/controller/app/spec"
	"forge.cadoles.com/Cadoles/emissary/internal/jwk"
	"forge.cadoles.com/arcad/edge/pkg/app"
	"forge.cadoles.com/arcad/edge/pkg/bus"
	"forge.cadoles.com/arcad/edge/pkg/bus/memory"
	edgeHTTP "forge.cadoles.com/arcad/edge/pkg/http"
	"forge.cadoles.com/arcad/edge/pkg/module"
	appModule "forge.cadoles.com/arcad/edge/pkg/module/app"
	"forge.cadoles.com/arcad/edge/pkg/module/auth"
	"forge.cadoles.com/arcad/edge/pkg/module/blob"
	"forge.cadoles.com/arcad/edge/pkg/module/cast"
	"forge.cadoles.com/arcad/edge/pkg/module/net"
	"forge.cadoles.com/arcad/edge/pkg/storage/sqlite"
	"github.com/Masterminds/sprig/v3"
	"github.com/dop251/goja"
	"github.com/lestrrat-go/jwx/v2/jwa"
	"github.com/pkg/errors"
)

func (c *Controller) getHandlerOptions(ctx context.Context, appKey string, specs *spec.Spec) ([]edgeHTTP.HandlerOptionFunc, error) {
	dataDir, err := c.ensureAppDataDir(ctx, appKey)
	if err != nil {
		return nil, errors.Wrap(err, "could not retrieve app data dir")
	}

	dbFile := filepath.Join(dataDir, appKey+".sqlite")
	db, err := sqlite.Open(dbFile)
	if err != nil {
		return nil, errors.Wrapf(err, "could not open database file '%s'", dbFile)
	}

	keySet, err := getAuthKeySet(specs.Config)
	if err != nil {
		return nil, errors.Wrap(err, "could not retrieve auth key set")
	}

	bundles := make([]string, 0, len(specs.Apps))
	for appKey, app := range specs.Apps {
		path := c.getAppBundlePath(appKey, app.Format)
		bundles = append(bundles, path)
	}

	getAppURL := createGetAppURL(specs)

	bus := memory.NewBus()
	modules := getAppModules(bus, db, specs, keySet, getAppURL, bundles)

	options := []edgeHTTP.HandlerOptionFunc{
		edgeHTTP.WithBus(bus),
		edgeHTTP.WithServerModules(modules...),
	}

	return options, nil
}

func getAuthKeySet(config *spec.Config) (jwk.Set, error) {
	keySet := jwk.NewSet()
	if config == nil {
		return nil, nil
	}

	auth := config.Auth

	if auth == nil {
		return nil, nil
	}

	switch {
	case auth.Local != nil:
		var (
			key jwk.Key
			err error
		)

		switch typedKey := auth.Local.Key.(type) {
		case string:
			key, err = jwk.FromRaw([]byte(typedKey))
			if err != nil {
				return nil, errors.Wrap(err, "could not parse local auth key")
			}

			if err := key.Set(jwk.AlgorithmKey, jwa.HS256); err != nil {
				return nil, errors.WithStack(err)
			}

		default:
			return nil, errors.Errorf("unexpected key type '%T'", auth.Local.Key)
		}

		if err := keySet.AddKey(key); err != nil {
			return nil, errors.WithStack(err)
		}
	}

	return keySet, nil
}

func createGetAppURL(specs *spec.Spec) GetURLFunc {
	var (
		compileOnce sync.Once
		urlTemplate *template.Template
		err         error
	)

	return func(ctx context.Context, manifest *app.Manifest) (string, error) {
		if err != nil {
			return "", errors.WithStack(err)
		}

		var appURLTemplate string

		if specs.Config == nil || specs.Config.AppURLTemplate == "" {
			appURLTemplate = `http://{{ last ( splitList "." ( toString .Manifest.ID ) ) }}.local`
		} else {
			appURLTemplate = specs.Config.AppURLTemplate
		}

		compileOnce.Do(func() {
			urlTemplate, err = template.New("").Funcs(sprig.TxtFuncMap()).Parse(appURLTemplate)
		})

		var buf bytes.Buffer

		data := struct {
			Manifest *app.Manifest
			Specs    *spec.Spec
		}{
			Manifest: manifest,
			Specs:    specs,
		}

		if err := urlTemplate.Execute(&buf, data); err != nil {
			return "", errors.WithStack(err)
		}

		return buf.String(), nil
	}
}

func getAppModules(bus bus.Bus, db *sql.DB, spec *appSpec.Spec, keySet jwk.Set, getAppURL GetURLFunc, bundles []string) []app.ServerModuleFactory {
	ds := sqlite.NewDocumentStoreWithDB(db)
	bs := sqlite.NewBlobStoreWithDB(db)

	return []app.ServerModuleFactory{
		module.ContextModuleFactory(),
		module.ConsoleModuleFactory(),
		cast.CastModuleFactory(),
		module.LifecycleModuleFactory(),
		net.ModuleFactory(bus),
		module.RPCModuleFactory(bus),
		module.StoreModuleFactory(ds),
		blob.ModuleFactory(bus, bs),
		module.Extends(
			auth.ModuleFactory(
				auth.WithJWT(func() (jwk.Set, error) {
					return keySet, nil
				}),
			),
			func(o *goja.Object) {
				if err := o.Set("CLAIM_TENANT", "arcad_tenant"); err != nil {
					panic(errors.New("could not set 'CLAIM_TENANT' property"))
				}

				if err := o.Set("CLAIM_ENTRYPOINT", "arcad_entrypoint"); err != nil {
					panic(errors.New("could not set 'CLAIM_ENTRYPOINT' property"))
				}

				if err := o.Set("CLAIM_ROLE", "arcad_role"); err != nil {
					panic(errors.New("could not set 'CLAIM_ROLE' property"))
				}

				if err := o.Set("CLAIM_PREFERRED_USERNAME", "preferred_username"); err != nil {
					panic(errors.New("could not set 'CLAIM_PREFERRED_USERNAME' property"))
				}
			},
		),
		appModule.ModuleFactory(NewAppRepository(getAppURL, bundles...)),
	}
}