WIP: Degrade more gracefully when the droplet limit is reached

src/server_manager/cloud/digitalocean_api.ts

@@ -49,6 +49,7 @@ export type Account = Readonly<{
   uuid: string;
   email_verified: boolean;
   status: string;
+  droplet_limit: number;
 }>;
 
 // Reference:

src/server_manager/model/digitalocean.ts

@@ -59,4 +59,6 @@ export interface Account {
   // Creates a server and returning it when it becomes active (i.e. the server has
   // created, not necessarily once shadowbox installation has finished).
   createServer(region: Region, name: string): Promise<ManagedServer>;
+
+  hasReachedLimit(): Promise<boolean>;
 }

src/server_manager/web_app/app.ts

@@ -720,6 +720,17 @@ export class App {
       return;
     }
 
+    try {
+      if (await digitalOceanAccount.hasReachedLimit()) {
+        this.appRoot.showError(
+          'Your DigitalOcean account has reached its Droplet limit.  You can request an increase at https://cloud.digitalocean.com/account/team/droplet_limit_increase'
+        );
+        return;
+      }
+    } catch (e) {
+      console.error('Failed to check droplet limit status', e);
+    }
+
     try {
       const regionPicker = this.appRoot.getAndShowRegionPicker();
       const map = await this.digitalOceanRetry(() => {

src/server_manager/web_app/digitalocean_account.ts

@@ -48,12 +48,18 @@ export class DigitalOceanAccount implements digitalocean.Account {
 
   async getStatus(): Promise<digitalocean.Status> {
     const account = await this.digitalOcean.getAccount();
-    if (account.status === 'active') {
+    if (account.status !== 'locked') {
       return digitalocean.Status.ACTIVE;
     }
     if (!account.email_verified) {
       return digitalocean.Status.EMAIL_UNVERIFIED;
     }
+    const servers = await this.digitalOcean.getDroplets();
+    if (servers.length > 0) {
+      // The account is locked, but it has droplets so it must have
+      // been activated with billing information.
+      return digitalocean.Status.ACTIVE;
+    }
     return digitalocean.Status.MISSING_BILLING_INFORMATION;
   }
 
@@ -67,6 +73,13 @@ export class DigitalOceanAccount implements digitalocean.Account {
     }));
   }
 
+  // Returns true if there is no more room for additional Droplets.
+  async hasReachedLimit(): Promise<boolean> {
+    const account = this.digitalOcean.getAccount();
+    const droplets = await this.digitalOcean.getDroplets();
+    return droplets.length >= (await account).droplet_limit;
+  }
+
   // Creates a server and returning it when it becomes active.
   async createServer(region: digitalocean.Region, name: string): Promise<server.ManagedServer> {
     console.time('activeServer');

src/server_manager/web_app/testing/models.ts

@@ -34,6 +34,9 @@ export class FakeDigitalOceanAccount implements digitalocean.Account {
   listServers() {
     return Promise.resolve(this.servers);
   }
+  async hasReachedLimit(): Promise<boolean> {
+    return false;
+  }
   listLocations() {
     return Promise.resolve([
       {