From 3c10c7f5f437f4c9379e2375bd9997a5c36868e7 Mon Sep 17 00:00:00 2001
From: Kyle Carberry <kyle@coder.com>
Date: Wed, 9 Nov 2022 11:01:34 -0600
Subject: [PATCH] fix: Subscribe to template updates on the workspace page
 (#4979)

Fixes #4969.
---
 coderd/templateversions.go | 17 +++++++++++++++++
 coderd/workspaces.go       | 22 +++++++++++++++++++---
 coderd/workspaces_test.go  |  6 ++++++
 3 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/coderd/templateversions.go b/coderd/templateversions.go
index 1d3ccb7919..330f0c39b6 100644
--- a/coderd/templateversions.go
+++ b/coderd/templateversions.go
@@ -1,6 +1,7 @@
 package coderd
 
 import (
+	"context"
 	"database/sql"
 	"encoding/json"
 	"errors"
@@ -12,6 +13,8 @@ import (
 	"github.com/moby/moby/pkg/namesgenerator"
 	"golang.org/x/xerrors"
 
+	"cdr.dev/slog"
+
 	"github.com/coder/coder/coderd/audit"
 	"github.com/coder/coder/coderd/database"
 	"github.com/coder/coder/coderd/httpapi"
@@ -660,6 +663,8 @@ func (api *API) patchActiveTemplateVersion(rw http.ResponseWriter, r *http.Reque
 	newTemplate.ActiveVersionID = req.ID
 	aReq.New = newTemplate
 
+	api.publishTemplateUpdate(ctx, template.ID)
+
 	httpapi.Write(ctx, rw, http.StatusOK, codersdk.Response{
 		Message: "Updated the active template version!",
 	})
@@ -946,3 +951,15 @@ func convertTemplateVersion(version database.TemplateVersion, job codersdk.Provi
 		CreatedBy:      createdBy,
 	}
 }
+
+func watchTemplateChannel(id uuid.UUID) string {
+	return fmt.Sprintf("template:%s", id)
+}
+
+func (api *API) publishTemplateUpdate(ctx context.Context, templateID uuid.UUID) {
+	err := api.Pubsub.Publish(watchTemplateChannel(templateID), []byte{})
+	if err != nil {
+		api.Logger.Warn(ctx, "failed to publish template update",
+			slog.F("template_id", templateID), slog.Error(err))
+	}
+}
diff --git a/coderd/workspaces.go b/coderd/workspaces.go
index 5a293a5a68..38d5310736 100644
--- a/coderd/workspaces.go
+++ b/coderd/workspaces.go
@@ -886,7 +886,7 @@ func (api *API) watchWorkspace(rw http.ResponseWriter, r *http.Request) {
 	// Ignore all trace spans after this, they're not too useful.
 	ctx = trace.ContextWithSpan(ctx, tracing.NoopSpan)
 
-	cancelSubscribe, err := api.Pubsub.Subscribe(watchWorkspaceChannel(workspace.ID), func(_ context.Context, _ []byte) {
+	sendUpdate := func(_ context.Context, _ []byte) {
 		workspace, err := api.Database.GetWorkspaceByID(ctx, workspace.ID)
 		if err != nil {
 			_ = sendEvent(ctx, codersdk.ServerSentEvent{
@@ -920,7 +920,9 @@ func (api *API) watchWorkspace(rw http.ResponseWriter, r *http.Request) {
 				findUser(workspace.OwnerID, data.users),
 			),
 		})
-	})
+	}
+
+	cancelWorkspaceSubscribe, err := api.Pubsub.Subscribe(watchWorkspaceChannel(workspace.ID), sendUpdate)
 	if err != nil {
 		_ = sendEvent(ctx, codersdk.ServerSentEvent{
 			Type: codersdk.ServerSentEventTypeError,
@@ -931,7 +933,21 @@ func (api *API) watchWorkspace(rw http.ResponseWriter, r *http.Request) {
 		})
 		return
 	}
-	defer cancelSubscribe()
+	defer cancelWorkspaceSubscribe()
+
+	// This is required to show whether the workspace is up-to-date.
+	cancelTemplateSubscribe, err := api.Pubsub.Subscribe(watchTemplateChannel(workspace.TemplateID), sendUpdate)
+	if err != nil {
+		_ = sendEvent(ctx, codersdk.ServerSentEvent{
+			Type: codersdk.ServerSentEventTypeError,
+			Data: codersdk.Response{
+				Message: "Internal error subscribing to template events.",
+				Detail:  err.Error(),
+			},
+		})
+		return
+	}
+	defer cancelTemplateSubscribe()
 
 	// An initial ping signals to the request that the server is now ready
 	// and the client can begin servicing a channel with data.
diff --git a/coderd/workspaces_test.go b/coderd/workspaces_test.go
index 0fbc9b973e..ca92537da0 100644
--- a/coderd/workspaces_test.go
+++ b/coderd/workspaces_test.go
@@ -1430,6 +1430,12 @@ func TestWorkspaceWatcher(t *testing.T) {
 	require.NoError(t, err)
 	wait()
 
+	err = client.UpdateActiveTemplateVersion(ctx, template.ID, codersdk.UpdateActiveTemplateVersion{
+		ID: template.ActiveVersionID,
+	})
+	require.NoError(t, err)
+	wait()
+
 	cancel()
 }