core/installer/welcome/dodo_app.go

package welcome

import (
	"context"
	"embed"
	"encoding/json"
	"errors"
	"fmt"
	"golang.org/x/crypto/bcrypt"
	"html/template"
	"io"
	"io/fs"
	"net/http"
	"slices"
	"strings"
	"sync"

	"github.com/giolekva/pcloud/core/installer"
	"github.com/giolekva/pcloud/core/installer/soft"

	"github.com/gorilla/mux"
	"github.com/gorilla/securecookie"
)

//go:embed dodo-app-tmpl/*
var dodoAppTmplFS embed.FS

const (
	ConfigRepoName = "config"
	namespacesFile = "/namespaces.json"
	loginPath      = "/login"
	logoutPath     = "/logout"
	sessionCookie  = "dodo-app-session"
	userCtx        = "user"
)

type dodoAppTmplts struct {
	index *template.Template
}

func parseTemplatesDodoApp(fs embed.FS) (dodoAppTmplts, error) {
	index, err := template.New("index.html").ParseFS(fs, "dodo-app-tmpl/index.html")
	if err != nil {
		return dodoAppTmplts{}, err
	}
	return dodoAppTmplts{index}, nil
}

type DodoAppServer struct {
	l                 sync.Locker
	st                Store
	nf                NetworkFilter
	ug                UserGetter
	port              int
	apiPort           int
	self              string
	repoPublicAddr    string
	sshKey            string
	gitRepoPublicKey  string
	client            soft.Client
	namespace         string
	envAppManagerAddr string
	env               installer.EnvConfig
	nsc               installer.NamespaceCreator
	jc                installer.JobCreator
	workers           map[string]map[string]struct{}
	appNs             map[string]string
	sc                *securecookie.SecureCookie
	tmplts            dodoAppTmplts
}

// TODO(gio): Initialize appNs on startup
func NewDodoAppServer(
	st Store,
	nf NetworkFilter,
	ug UserGetter,
	port int,
	apiPort int,
	self string,
	repoPublicAddr string,
	sshKey string,
	gitRepoPublicKey string,
	client soft.Client,
	namespace string,
	envAppManagerAddr string,
	nsc installer.NamespaceCreator,
	jc installer.JobCreator,
	env installer.EnvConfig,
) (*DodoAppServer, error) {
	tmplts, err := parseTemplatesDodoApp(dodoAppTmplFS)
	if err != nil {
		return nil, err
	}
	sc := securecookie.New(
		securecookie.GenerateRandomKey(64),
		securecookie.GenerateRandomKey(32),
	)
	s := &DodoAppServer{
		&sync.Mutex{},
		st,
		nf,
		ug,
		port,
		apiPort,
		self,
		repoPublicAddr,
		sshKey,
		gitRepoPublicKey,
		client,
		namespace,
		envAppManagerAddr,
		env,
		nsc,
		jc,
		map[string]map[string]struct{}{},
		map[string]string{},
		sc,
		tmplts,
	}
	config, err := client.GetRepo(ConfigRepoName)
	if err != nil {
		return nil, err
	}
	r, err := config.Reader(namespacesFile)
	if err == nil {
		defer r.Close()
		if err := json.NewDecoder(r).Decode(&s.appNs); err != nil {
			return nil, err
		}
	} else if !errors.Is(err, fs.ErrNotExist) {
		return nil, err
	}
	return s, nil
}

func (s *DodoAppServer) Start() error {
	e := make(chan error)
	go func() {
		r := mux.NewRouter()
		r.Use(s.mwAuth)
		r.HandleFunc(logoutPath, s.handleLogout).Methods(http.MethodGet)
		r.HandleFunc("/{app-name}"+loginPath, s.handleLoginForm).Methods(http.MethodGet)
		r.HandleFunc("/{app-name}"+loginPath, s.handleLogin).Methods(http.MethodPost)
		r.HandleFunc("/{app-name}", s.handleAppStatus).Methods(http.MethodGet)
		r.HandleFunc("/", s.handleStatus).Methods(http.MethodGet)
		r.HandleFunc("/", s.handleCreateApp).Methods(http.MethodPost)
		e <- http.ListenAndServe(fmt.Sprintf(":%d", s.port), r)
	}()
	go func() {
		r := mux.NewRouter()
		r.HandleFunc("/update", s.handleApiUpdate)
		r.HandleFunc("/api/apps/{app-name}/workers", s.handleApiRegisterWorker).Methods(http.MethodPost)
		r.HandleFunc("/api/apps", s.handleApiCreateApp).Methods(http.MethodPost)
		r.HandleFunc("/api/add-admin-key", s.handleApiAddAdminKey).Methods(http.MethodPost)
		e <- http.ListenAndServe(fmt.Sprintf(":%d", s.apiPort), r)
	}()
	return <-e
}

type UserGetter interface {
	Get(r *http.Request) string
}

type externalUserGetter struct {
	sc *securecookie.SecureCookie
}

func NewExternalUserGetter() UserGetter {
	return &externalUserGetter{}
}

func (ug *externalUserGetter) Get(r *http.Request) string {
	cookie, err := r.Cookie(sessionCookie)
	if err != nil {
		return ""
	}
	var user string
	if err := ug.sc.Decode(sessionCookie, cookie.Value, &user); err != nil {
		return ""
	}
	return user
}

type internalUserGetter struct{}

func NewInternalUserGetter() UserGetter {
	return internalUserGetter{}
}

func (ug internalUserGetter) Get(r *http.Request) string {
	return r.Header.Get("X-User")
}

func (s *DodoAppServer) mwAuth(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if strings.HasSuffix(r.URL.Path, loginPath) || strings.HasPrefix(r.URL.Path, logoutPath) {
			next.ServeHTTP(w, r)
			return
		}
		user := s.ug.Get(r)
		if user == "" {
			vars := mux.Vars(r)
			appName, ok := vars["app-name"]
			if !ok || appName == "" {
				http.Error(w, "missing app-name", http.StatusBadRequest)
				return
			}
			http.Redirect(w, r, fmt.Sprintf("/%s%s", appName, loginPath), http.StatusSeeOther)
			return
		}
		next.ServeHTTP(w, r.WithContext(context.WithValue(r.Context(), userCtx, user)))
	})
}

func (s *DodoAppServer) handleLogout(w http.ResponseWriter, r *http.Request) {
	http.SetCookie(w, &http.Cookie{
		Name:     sessionCookie,
		Value:    "",
		Path:     "/",
		HttpOnly: true,
		Secure:   true,
	})
	http.Redirect(w, r, "/", http.StatusSeeOther)
}

func (s *DodoAppServer) handleLoginForm(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	appName, ok := vars["app-name"]
	if !ok || appName == "" {
		http.Error(w, "missing app-name", http.StatusBadRequest)
		return
	}
	fmt.Fprint(w, `
<!DOCTYPE html>
<html lang='en'>
	<head>
		<title>dodo: app - login</title>
		<meta charset='utf-8'>
	</head>
	<body>
        <form action="" method="POST">
          <input type="password" placeholder="Password" name="password" required />
          <button type="submit">Login</button>
        </form>
	</body>
</html>
`)
}

func (s *DodoAppServer) handleLogin(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	appName, ok := vars["app-name"]
	if !ok || appName == "" {
		http.Error(w, "missing app-name", http.StatusBadRequest)
		return
	}
	password := r.FormValue("password")
	if password == "" {
		http.Error(w, "missing password", http.StatusBadRequest)
		return
	}
	user, err := s.st.GetAppOwner(appName)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	hashed, err := s.st.GetUserPassword(user)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if err := bcrypt.CompareHashAndPassword(hashed, []byte(password)); err != nil {
		http.Redirect(w, r, r.URL.Path, http.StatusSeeOther)
		return
	}
	if encoded, err := s.sc.Encode(sessionCookie, user); err == nil {
		cookie := &http.Cookie{
			Name:     sessionCookie,
			Value:    encoded,
			Path:     "/",
			Secure:   true,
			HttpOnly: true,
		}
		http.SetCookie(w, cookie)
	}
	http.Redirect(w, r, fmt.Sprintf("/%s", appName), http.StatusSeeOther)
}

type statusData struct {
	Apps     []string
	Networks []installer.Network
}

func (s *DodoAppServer) handleStatus(w http.ResponseWriter, r *http.Request) {
	user := r.Context().Value(userCtx)
	if user == nil {
		http.Error(w, "unauthorized", http.StatusUnauthorized)
		return
	}
	apps, err := s.st.GetUserApps(user.(string))
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	networks, err := s.getNetworks(user.(string))
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	data := statusData{apps, networks}
	if err := s.tmplts.index.Execute(w, data); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
}

func (s *DodoAppServer) handleAppStatus(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	appName, ok := vars["app-name"]
	if !ok || appName == "" {
		http.Error(w, "missing app-name", http.StatusBadRequest)
		return
	}
	fmt.Fprintf(w, "git clone %s/%s\n\n\n", s.repoPublicAddr, appName)
	commits, err := s.st.GetCommitHistory(appName)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	for _, c := range commits {
		fmt.Fprintf(w, "%s %s\n", c.Hash, c.Message)
	}
}

type apiUpdateReq struct {
	Ref        string `json:"ref"`
	Repository struct {
		Name string `json:"name"`
	} `json:"repository"`
	After string `json:"after"`
}

func (s *DodoAppServer) handleApiUpdate(w http.ResponseWriter, r *http.Request) {
	fmt.Println("update")
	var req apiUpdateReq
	var contents strings.Builder
	io.Copy(&contents, r.Body)
	c := contents.String()
	fmt.Println(c)
	if err := json.NewDecoder(strings.NewReader(c)).Decode(&req); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	if req.Ref != "refs/heads/master" || req.Repository.Name == ConfigRepoName {
		return
	}
	// TODO(gio): Create commit record on app init as well
	go func() {
		owner, err := s.st.GetAppOwner(req.Repository.Name)
		if err != nil {
			return
		}
		networks, err := s.getNetworks(owner)
		if err != nil {
			return
		}
		if err := s.updateDodoApp(req.Repository.Name, s.appNs[req.Repository.Name], networks); err != nil {
			if err := s.st.CreateCommit(req.Repository.Name, req.After, err.Error()); err != nil {
				fmt.Printf("Error: %s\n", err.Error())
				return
			}
		}
		if err := s.st.CreateCommit(req.Repository.Name, req.After, "OK"); err != nil {
			fmt.Printf("Error: %s\n", err.Error())
		}
		for addr, _ := range s.workers[req.Repository.Name] {
			go func() {
				// TODO(gio): make port configurable
				http.Get(fmt.Sprintf("http://%s/update", addr))
			}()
		}
	}()
}

type apiRegisterWorkerReq struct {
	Address string `json:"address"`
}

func (s *DodoAppServer) handleApiRegisterWorker(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	appName, ok := vars["app-name"]
	if !ok || appName == "" {
		http.Error(w, "missing app-name", http.StatusBadRequest)
		return
	}
	var req apiRegisterWorkerReq
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if _, ok := s.workers[appName]; !ok {
		s.workers[appName] = map[string]struct{}{}
	}
	s.workers[appName][req.Address] = struct{}{}
}

func (s *DodoAppServer) handleCreateApp(w http.ResponseWriter, r *http.Request) {
	u := r.Context().Value(userCtx)
	if u == nil {
		http.Error(w, "unauthorized", http.StatusUnauthorized)
		return
	}
	user, ok := u.(string)
	if !ok {
		http.Error(w, "could not get user", http.StatusInternalServerError)
		return
	}
	network := r.FormValue("network")
	if network == "" {
		http.Error(w, "missing network", http.StatusBadRequest)
		return
	}
	adminPublicKey := r.FormValue("admin-public-key")
	if network == "" {
		http.Error(w, "missing admin public key", http.StatusBadRequest)
		return
	}
	g := installer.NewFixedLengthRandomNameGenerator(3)
	appName, err := g.Generate()
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if ok, err := s.client.UserExists(user); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	} else if !ok {
		if err := s.client.AddUser(user, adminPublicKey); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
	}
	if err := s.st.CreateUser(user, nil, adminPublicKey, network); err != nil && !errors.Is(err, ErrorAlreadyExists) {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if err := s.st.CreateApp(appName, user); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if err := s.CreateApp(user, appName, adminPublicKey, network); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	http.Redirect(w, r, fmt.Sprintf("/%s", appName), http.StatusSeeOther)
}

type apiCreateAppReq struct {
	AdminPublicKey string `json:"adminPublicKey"`
	Network        string `json:"network"`
}

type apiCreateAppResp struct {
	AppName  string `json:"appName"`
	Password string `json:"password"`
}

func (s *DodoAppServer) handleApiCreateApp(w http.ResponseWriter, r *http.Request) {
	var req apiCreateAppReq
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	g := installer.NewFixedLengthRandomNameGenerator(3)
	appName, err := g.Generate()
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	user, err := s.client.FindUser(req.AdminPublicKey)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if user != "" {
		http.Error(w, "public key already registered", http.StatusBadRequest)
		return
	}
	user = appName
	if err := s.client.AddUser(user, req.AdminPublicKey); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	password := generatePassword()
	hashed, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if err := s.st.CreateUser(user, hashed, req.AdminPublicKey, req.Network); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if err := s.st.CreateApp(appName, user); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if err := s.CreateApp(user, appName, req.AdminPublicKey, req.Network); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	resp := apiCreateAppResp{
		AppName:  appName,
		Password: password,
	}
	if err := json.NewEncoder(w).Encode(resp); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
}

func (s *DodoAppServer) CreateApp(user, appName, adminPublicKey, network string) error {
	s.l.Lock()
	defer s.l.Unlock()
	fmt.Printf("Creating app: %s\n", appName)
	if ok, err := s.client.RepoExists(appName); err != nil {
		return err
	} else if ok {
		return nil
	}
	if err := s.client.AddRepository(appName); err != nil {
		return err
	}
	appRepo, err := s.client.GetRepo(appName)
	if err != nil {
		return err
	}
	if err := InitRepo(appRepo, network); err != nil {
		return err
	}
	apps := installer.NewInMemoryAppRepository(installer.CreateAllApps())
	app, err := installer.FindEnvApp(apps, "dodo-app-instance")
	if err != nil {
		return err
	}
	suffixGen := installer.NewFixedLengthRandomSuffixGenerator(3)
	suffix, err := suffixGen.Generate()
	if err != nil {
		return err
	}
	namespace := fmt.Sprintf("%s%s%s", s.env.NamespacePrefix, app.Namespace(), suffix)
	s.appNs[appName] = namespace
	networks, err := s.getNetworks(user)
	if err != nil {
		return err
	}
	if err := s.updateDodoApp(appName, namespace, networks); err != nil {
		return err
	}
	repo, err := s.client.GetRepo(ConfigRepoName)
	if err != nil {
		return err
	}
	hf := installer.NewGitHelmFetcher()
	m, err := installer.NewAppManager(repo, s.nsc, s.jc, hf, "/")
	if err != nil {
		return err
	}
	if err := repo.Do(func(fs soft.RepoFS) (string, error) {
		w, err := fs.Writer(namespacesFile)
		if err != nil {
			return "", err
		}
		defer w.Close()
		if err := json.NewEncoder(w).Encode(s.appNs); err != nil {
			return "", err
		}
		if _, err := m.Install(
			app,
			appName,
			"/"+appName,
			namespace,
			map[string]any{
				"repoAddr":         s.client.GetRepoAddress(appName),
				"repoHost":         strings.Split(s.client.Address(), ":")[0],
				"gitRepoPublicKey": s.gitRepoPublicKey,
			},
			installer.WithConfig(&s.env),
			installer.WithNoNetworks(),
			installer.WithNoPublish(),
			installer.WithNoLock(),
		); err != nil {
			return "", err
		}
		return fmt.Sprintf("Installed app: %s", appName), nil
	}); err != nil {
		return err
	}
	cfg, err := m.FindInstance(appName)
	if err != nil {
		return err
	}
	fluxKeys, ok := cfg.Input["fluxKeys"]
	if !ok {
		return fmt.Errorf("Fluxcd keys not found")
	}
	fluxPublicKey, ok := fluxKeys.(map[string]any)["public"]
	if !ok {
		return fmt.Errorf("Fluxcd keys not found")
	}
	if ok, err := s.client.UserExists("fluxcd"); err != nil {
		return err
	} else if ok {
		if err := s.client.AddPublicKey("fluxcd", fluxPublicKey.(string)); err != nil {
			return err
		}
	} else {
		if err := s.client.AddUser("fluxcd", fluxPublicKey.(string)); err != nil {
			return err
		}
	}
	if err := s.client.AddReadOnlyCollaborator(appName, "fluxcd"); err != nil {
		return err
	}
	if err := s.client.AddWebhook(appName, fmt.Sprintf("http://%s/update", s.self), "--active=true", "--events=push", "--content-type=json"); err != nil {
		return err
	}
	if err := s.client.AddReadWriteCollaborator(appName, user); err != nil {
		return err
	}
	return nil
}

type apiAddAdminKeyReq struct {
	Public string `json:"public"`
}

func (s *DodoAppServer) handleApiAddAdminKey(w http.ResponseWriter, r *http.Request) {
	var req apiAddAdminKeyReq
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	if err := s.client.AddPublicKey("admin", req.Public); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
}

func (s *DodoAppServer) updateDodoApp(name, namespace string, networks []installer.Network) error {
	repo, err := s.client.GetRepo(name)
	if err != nil {
		return err
	}
	hf := installer.NewGitHelmFetcher()
	m, err := installer.NewAppManager(repo, s.nsc, s.jc, hf, "/.dodo")
	if err != nil {
		return err
	}
	appCfg, err := soft.ReadFile(repo, "app.cue")
	if err != nil {
		return err
	}
	app, err := installer.NewDodoApp(appCfg)
	if err != nil {
		return err
	}
	lg := installer.GitRepositoryLocalChartGenerator{"app", namespace}
	if _, err := m.Install(
		app,
		"app",
		"/.dodo/app",
		namespace,
		map[string]any{
			"repoAddr":      repo.FullAddress(),
			"managerAddr":   fmt.Sprintf("http://%s", s.self),
			"appId":         name,
			"sshPrivateKey": s.sshKey,
		},
		installer.WithConfig(&s.env),
		installer.WithNetworks(networks),
		installer.WithLocalChartGenerator(lg),
		installer.WithBranch("dodo"),
		installer.WithForce(),
	); err != nil {
		return err
	}
	return nil
}

const goMod = `module dodo.app

go 1.18
`

const mainGo = `package main

import (
	"flag"
	"fmt"
	"log"
	"net/http"
)

var port = flag.Int("port", 8080, "Port to listen on")

func handler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintln(w, "Hello from Dodo App!")
}

func main() {
	flag.Parse()
	http.HandleFunc("/", handler)
	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%d", *port), nil))
}
`

const appCue = `app: {
	type: "golang:1.22.0"
	run: "main.go"
	ingress: {
		network: "%s"
		subdomain: "testapp"
		auth: enabled: false
	}
}
`

func InitRepo(repo soft.RepoIO, network string) error {
	return repo.Do(func(fs soft.RepoFS) (string, error) {
		{
			w, err := fs.Writer("go.mod")
			if err != nil {
				return "", err
			}
			defer w.Close()
			fmt.Fprint(w, goMod)
		}
		{
			w, err := fs.Writer("main.go")
			if err != nil {
				return "", err
			}
			defer w.Close()
			fmt.Fprintf(w, "%s", mainGo)
		}
		{
			w, err := fs.Writer("app.cue")
			if err != nil {
				return "", err
			}
			defer w.Close()
			fmt.Fprintf(w, appCue, network)
		}
		return "go web app template", nil
	})
}

func generatePassword() string {
	return "foo"
}

func (s *DodoAppServer) getNetworks(user string) ([]installer.Network, error) {
	addr := fmt.Sprintf("%s/api/networks", s.envAppManagerAddr)
	resp, err := http.Get(addr)
	if err != nil {
		return nil, err
	}
	networks := []installer.Network{}
	if json.NewDecoder(resp.Body).Decode(&networks); err != nil {
		return nil, err
	}
	return s.nf.Filter(user, networks)
}

func pickNetwork(networks []installer.Network, network string) []installer.Network {
	for _, n := range networks {
		if n.Name == network {
			return []installer.Network{n}
		}
	}
	return []installer.Network{}
}

type NetworkFilter interface {
	Filter(user string, networks []installer.Network) ([]installer.Network, error)
}

type noNetworkFilter struct{}

func NewNoNetworkFilter() NetworkFilter {
	return noNetworkFilter{}
}

func (f noNetworkFilter) Filter(app string, networks []installer.Network) ([]installer.Network, error) {
	return networks, nil
}

type filterByOwner struct {
	st Store
}

func NewNetworkFilterByOwner(st Store) NetworkFilter {
	return &filterByOwner{st}
}

func (f *filterByOwner) Filter(user string, networks []installer.Network) ([]installer.Network, error) {
	network, err := f.st.GetUserNetwork(user)
	if err != nil {
		return nil, err
	}
	ret := []installer.Network{}
	for _, n := range networks {
		if n.Name == network {
			ret = append(ret, n)
		}
	}
	return ret, nil
}

type allowListFilter struct {
	allowed []string
}

func NewAllowListFilter(allowed []string) NetworkFilter {
	return &allowListFilter{allowed}
}

func (f *allowListFilter) Filter(app string, networks []installer.Network) ([]installer.Network, error) {
	ret := []installer.Network{}
	for _, n := range networks {
		if slices.Contains(f.allowed, n.Name) {
			ret = append(ret, n)
		}
	}
	return ret, nil
}

type combinedNetworkFilter struct {
	filters []NetworkFilter
}

func NewCombinedFilter(filters ...NetworkFilter) NetworkFilter {
	return &combinedNetworkFilter{filters}
}

func (f *combinedNetworkFilter) Filter(app string, networks []installer.Network) ([]installer.Network, error) {
	ret := networks
	var err error
	for _, f := range f.filters {
		ret, err = f.Filter(app, ret)
		if err != nil {
			return nil, err
		}
	}
	return ret, nil
}