Client + Server: Pass discovery manager and lock when needed

4 files changed, 123 insertions, 16 deletions

diff --git a/internal/discovery/manager.go b/internal/discovery/manager.go
new file mode 100644
index 0000000..b84e770
--- /dev/null
+++ b/internal/discovery/manager.go
@@ -0,0 +1,88 @@
+package discovery
+
+import (
+	"context"
+	"sync"
+
+	"github.com/eduvpn/eduvpn-common/internal/log"
+)
+
+type Manager struct {
+	disco *Discovery
+
+	cancel context.CancelFunc
+	mu     sync.RWMutex
+	wait   sync.WaitGroup
+}
+
+func NewManager(disco *Discovery) *Manager {
+	return &Manager{disco: disco}
+}
+
+func (m *Manager) lock(write bool) {
+	log.Logger.Debugf("Locking write: %v", write)
+	if write {
+		m.mu.Lock()
+		return
+	}
+	m.mu.RLock()
+}
+
+func (m *Manager) unlock(write bool) {
+	log.Logger.Debugf("Unlocking write: %v", write)
+	if write {
+		m.mu.Unlock()
+		return
+	}
+	m.mu.RUnlock()
+}
+
+func (m *Manager) Discovery(write bool) (*Discovery, func()) {
+	log.Logger.Debugf("Requesting discovery write: %v", write)
+	if write {
+		m.wait.Wait()
+	}
+	m.lock(write)
+	return m.disco, func() {
+		m.unlock(write)
+	}
+}
+
+func (m *Manager) Cancel() {
+	if m.cancel != nil {
+		m.cancel()
+	}
+	m.wait.Wait()
+}
+
+func (m *Manager) Startup(ctx context.Context, cb func()) {
+	ctx, cancel := context.WithCancel(ctx)
+	m.cancel = cancel
+	m.wait.Add(1)
+	go func() {
+		m.lock(false)
+		discoCopy, err := m.disco.Copy()
+		if err != nil {
+			log.Logger.Warningf("internal error, failed to clone discovery, %v", err)
+			return
+		}
+		m.unlock(false)
+		// we already log the warning
+		discoCopy.Servers(ctx) //nolint:errcheck
+
+		m.lock(true)
+		m.disco.UpdateServers(discoCopy)
+		m.unlock(true)
+		m.wait.Done()
+
+		select {
+		case <-ctx.Done():
+			return
+		default:
+			if cb == nil {
+				return
+			}
+			cb()
+		}
+	}()
+}
diff --git a/internal/server/institute.go b/internal/server/institute.go
index caae004..4ddf939 100644
--- a/internal/server/institute.go
+++ b/internal/server/institute.go
@@ -17,12 +17,15 @@ import (
 // `disco` are the discovery servers
 // `id` is the identifier for the server, the base url
 // `ot` specifies specifies the start time OAuth was already triggered
-func (s *Servers) AddInstitute(ctx context.Context, disco *discovery.Discovery, id string, ot *int64) error {
+func (s *Servers) AddInstitute(ctx context.Context, discom *discovery.Manager, id string, ot *int64) error {
 	// This is basically done to double check if the server is part of the institute access section of disco
+	disco, release := discom.Discovery(false)
 	dsrv, err := disco.ServerByURL(id, "institute_access")
 	if err != nil {
+		release()
 		return err
 	}
+	release()
 
 	sd := api.ServerData{
 		ID:         dsrv.BaseURL,
@@ -67,12 +70,15 @@ func (s *Servers) AddInstitute(ctx context.Context, disco *discovery.Discovery,
 // `disco` are the discovery servers
 // `tok` are the tokens such that we do not have to trigger auth
 // `disableAuth` is true when auth should never be triggered
-func (s *Servers) GetInstitute(ctx context.Context, id string, disco *discovery.Discovery, tok *eduoauth.Token, disableAuth bool) (*Server, error) {
+func (s *Servers) GetInstitute(ctx context.Context, id string, discom *discovery.Manager, tok *eduoauth.Token, disableAuth bool) (*Server, error) {
+	disco, release := discom.Discovery(false)
 	// This is basically done to double check if the server is part of the institute access section of disco
 	dsrv, err := disco.ServerByURL(id, "institute_access")
 	if err != nil {
+		release()
 		return nil, err
 	}
+	release()
 
 	// Get the server from the config
 	_, err = s.config.GetServer(dsrv.BaseURL, server.TypeInstituteAccess)
diff --git a/internal/server/secureinternet.go b/internal/server/secureinternet.go
index 990ceb3..9b4b873 100644
--- a/internal/server/secureinternet.go
+++ b/internal/server/secureinternet.go
@@ -19,14 +19,17 @@ import (
 // `disco` are the discovery servers
 // `orgID` is the organiztaion ID
 // `ot` specifies specifies the start time OAuth was already triggered
-func (s *Servers) AddSecure(ctx context.Context, disco *discovery.Discovery, orgID string, ot *int64) error {
+func (s *Servers) AddSecure(ctx context.Context, discom *discovery.Manager, orgID string, ot *int64) error {
 	if s.config.HasSecureInternet() {
 		return errors.New("a secure internet server already exists")
 	}
+	disco, release := discom.Discovery(false)
 	dorg, dsrv, err := disco.SecureHomeArgs(orgID)
 	if err != nil {
+		release()
 		return err
 	}
+	release()
 
 	sd := api.ServerData{
 		ID:         dorg.OrgID,
@@ -34,11 +37,13 @@ func (s *Servers) AddSecure(ctx context.Context, disco *discovery.Discovery, org
 		BaseWK:     dsrv.BaseURL,
 		BaseAuthWK: dsrv.BaseURL,
 		ProcessAuth: func(ctx context.Context, url string) (string, error) {
+			newd, release := discom.Discovery(true)
+			defer release()
 			// the only thing we can do is log warn
 			// this is already done in the functions
-			disco.Servers(ctx) //nolint:errcheck
-			disco.Organizations(ctx) //nolint:errcheck
-			updorg, updsrv, err := disco.SecureHomeArgs(orgID)
+			newd.Servers(ctx)       //nolint:errcheck
+			newd.Organizations(ctx) //nolint:errcheck
+			updorg, updsrv, err := newd.SecureHomeArgs(orgID)
 			if err != nil {
 				return "", err
 			}
@@ -84,21 +89,25 @@ func (s *Servers) AddSecure(ctx context.Context, disco *discovery.Discovery, org
 // `disco` are the discovery servers
 // `tok` are the tokens such that the server can be found without triggering auth
 // `disableAuth` is set to true when authorization should not be triggered
-func (s *Servers) GetSecure(ctx context.Context, orgID string, disco *discovery.Discovery, tok *eduoauth.Token, disableAuth bool) (*Server, error) {
+func (s *Servers) GetSecure(ctx context.Context, orgID string, discom *discovery.Manager, tok *eduoauth.Token, disableAuth bool) (*Server, error) {
 	srv, err := s.config.GetServer(orgID, server.TypeSecureInternet)
 	if err != nil {
 		return nil, err
 	}
 
+	disco, release := discom.Discovery(false)
 	dorg, dhome, err := disco.SecureHomeArgs(orgID)
 	if err != nil {
+		release()
 		return nil, err
 	}
 
 	dloc, err := disco.ServerByCountryCode(srv.CountryCode)
 	if err != nil {
+		release()
 		return nil, err
 	}
+	release()
 
 	sd := api.ServerData{
 		ID:         dorg.OrgID,
@@ -106,13 +115,15 @@ func (s *Servers) GetSecure(ctx context.Context, orgID string, disco *discovery.
 		BaseWK:     dloc.BaseURL,
 		BaseAuthWK: dhome.BaseURL,
 		ProcessAuth: func(ctx context.Context, url string) (string, error) {
+			newd, release := discom.Discovery(true)
+			defer release()
 			// the only thing we can do is log warn
 			// this is already done in the functions
-			disco.MarkServersExpired()
-			disco.Servers(ctx) //nolint:errcheck
-			disco.MarkOrganizationsExpired()
-			disco.Organizations(ctx) //nolint:errcheck
-			updorg, updsrv, err := disco.SecureHomeArgs(orgID)
+			newd.MarkServersExpired()
+			newd.Servers(ctx) //nolint:errcheck
+			newd.MarkOrganizationsExpired()
+			newd.Organizations(ctx) //nolint:errcheck
+			updorg, updsrv, err := newd.SecureHomeArgs(orgID)
 			if err != nil {
 				return "", err
 			}
diff --git a/internal/server/servers.go b/internal/server/servers.go
index 8285801..d06c37d 100644
--- a/internal/server/servers.go
+++ b/internal/server/servers.go
@@ -54,12 +54,12 @@ type CurrentServer struct {
 }
 
 // ServerWithCallbacks gets the current server as a server struct and triggers callbacks as needed
-func (cs *CurrentServer) ServerWithCallbacks(ctx context.Context, disco *discovery.Discovery, tokens *eduoauth.Token, disableAuth bool) (*Server, error) {
+func (cs *CurrentServer) ServerWithCallbacks(ctx context.Context, discom *discovery.Manager, tokens *eduoauth.Token, disableAuth bool) (*Server, error) {
 	switch cs.Key.T {
 	case srvtypes.TypeInstituteAccess:
-		return cs.srvs.GetInstitute(ctx, cs.Key.ID, disco, tokens, disableAuth)
+		return cs.srvs.GetInstitute(ctx, cs.Key.ID, discom, tokens, disableAuth)
 	case srvtypes.TypeSecureInternet:
-		return cs.srvs.GetSecure(ctx, cs.Key.ID, disco, tokens, disableAuth)
+		return cs.srvs.GetSecure(ctx, cs.Key.ID, discom, tokens, disableAuth)
 	case srvtypes.TypeCustom:
 		return cs.srvs.GetCustom(ctx, cs.Key.ID, tokens, disableAuth)
 	default:
@@ -89,7 +89,9 @@ func (s *Servers) CurrentServer() (*CurrentServer, error) {
 }
 
 // PublicCurrent gets the current server into a type that we can return to the client
-func (s *Servers) PublicCurrent(disco *discovery.Discovery) (*srvtypes.Current, error) {
+func (s *Servers) PublicCurrent(discom *discovery.Manager) (*srvtypes.Current, error) {
+	disco, release := discom.Discovery(false)
+	defer release()
 	return s.config.PublicCurrent(disco)
 }