local sandbox: recreate a parked container whose docker network is gone

src/sandbox/local-sandbox.ts

@@ -146,6 +146,21 @@ export function createLocalSandbox(workspace: WorkspaceStore, opts: LocalSandbox
     return { running: running === "true", imageId };
   }
 
+  async function networksIntact(name: string): Promise<boolean> {
+    const r = await dexec(["inspect", "-f", "{{json .NetworkSettings.Networks}}", name]);
+    if (r.code !== 0) return false;
+    let endpoints: Record<string, { NetworkID?: string }>;
+    try {
+      endpoints = JSON.parse(r.stdout.trim() || "{}");
+    } catch {
+      return false;
+    }
+    for (const endpoint of Object.values(endpoints ?? {})) {
+      if (endpoint.NetworkID && (await dexec(["network", "inspect", endpoint.NetworkID])).code !== 0) return false;
+    }
+    return true;
+  }
+
   async function resolvePort(name: string): Promise<number> {
     const cached = portByName.get(name);
     if (cached) return cached;
@@ -293,7 +308,7 @@ export function createLocalSandbox(workspace: WorkspaceStore, opts: LocalSandbox
       const name = localContainerName(scope);
       scopeByContainer.set(name, scope);
       const state = await containerState(name);
-      if (state && state.imageId === imageId) {
+      if (state && state.imageId === imageId && (state.running || (await networksIntact(name)))) {
         if (!state.running) await startContainer(name);
         else await connectCore(await ensureNetwork(name));
         activeByContainer.set(name, (activeByContainer.get(name) ?? 0) + 1);
@@ -318,12 +333,13 @@ export function createLocalSandbox(workspace: WorkspaceStore, opts: LocalSandbox
       const name = localScratchName(key);
       scratchByKey.set(key, name);
       const state = await containerState(name);
-      if (state) {
+      if (state && (state.running || (await networksIntact(name)))) {
         if (!state.running) await startContainer(name);
         else await connectCore(await ensureNetwork(name));
         activeByContainer.set(name, (activeByContainer.get(name) ?? 0) + 1);
         return { name, coldStart: false };
       }
+      if (state) await dexec(["rm", "-f", name]);
       await runContainer(name, undefined, false);
       activeByContainer.set(name, (activeByContainer.get(name) ?? 0) + 1);
       return { name, coldStart: true };

test/local-sandbox.test.ts

@@ -314,3 +314,38 @@ test("containerized core joins each sandbox network and reaches the daemon by co
   await sb.teardown(h, { destroy: true });
   assert.equal(fake.connections.has(`${localNetworkName(h.id)}|qm-test-core`), false);
 });
+
+test("a parked container whose network was pruned is recreated with its home volume", async () => {
+  const fake = installFakeDocker(daemonPort);
+  const sb = makeSandbox(fake);
+  const layers = rw(scopeId("personal", "U41"));
+  const h1 = await sb.provision(layers);
+  await sb.teardown(h1);
+  assert.equal(fake.containers.get(h1.id)!.running, false);
+  const volume = fake.containers.get(h1.id)!.volume!;
+  fake.networks.delete(localNetworkName(h1.id));
+
+  const h2 = await makeSandbox(fake).provision(layers);
+  assert.equal(h2.id, h1.id);
+  assert.equal(fake.runCount, 2, "container recreated after its network vanished");
+  assert.equal(fake.containers.get(h2.id)!.running, true);
+  assert.equal(fake.volumes.has(volume), true, "volume survived the recreate");
+  assert.equal(fake.containers.get(h2.id)!.volume, volume, "recreate remounted the same volume");
+  assert.equal(fake.networks.has(localNetworkName(h1.id)), true, "network recreated");
+  assert.equal(h2.coldStart, false, "existing volume means a warm home");
+});
+
+test("a parked scratch box whose network was pruned is recreated", async () => {
+  const fake = installFakeDocker(daemonPort);
+  const sb = makeSandbox(fake);
+  const layers = rw(scopeId("personal", "U42"));
+  const h1 = await sb.provision(layers, { scratch: { key: "pruned" } });
+  fake.containers.get(h1.id)!.running = false;
+  fake.networks.delete(localNetworkName(h1.id));
+
+  const h2 = await sb.provision(layers, { scratch: { key: "pruned" } });
+  assert.equal(h2.id, h1.id);
+  assert.equal(fake.runCount, 2, "scratch container recreated");
+  assert.equal(fake.containers.get(h2.id)!.running, true);
+  assert.equal(fake.networks.has(localNetworkName(h1.id)), true, "network recreated");
+});

test/support/fake-docker.ts

@@ -6,6 +6,7 @@ export interface FakeContainer {
   running: boolean;
   labels: Record<string, string>;
   volume?: string;
+  network?: string;
   args: string[];
 }
 
@@ -54,6 +55,7 @@ export function installFakeDocker(daemonPort: number): FakeDocker {
         const [k = "", v = ""] = args[++i]!.split("=");
         c.labels[k] = v;
       } else if (a === "-v") c.volume = args[++i]!.split(":")[0]!;
+      else if (a === "--network") c.network = args[++i]!;
       else if (a === "-p" || a === "--cpus" || a === "--memory") i++;
     }
     return c;
@@ -75,6 +77,8 @@ export function installFakeDocker(daemonPort: number): FakeDocker {
         const name = rest[rest.length - 1]!;
         const c = containers.get(name);
         if (!c) return fail(`Error: No such object: ${name}`);
+        if (rest.includes("{{json .NetworkSettings.Networks}}"))
+          return ok(JSON.stringify(c.network ? { [c.network]: { NetworkID: c.network } } : {}));
         return ok(`${c.running} ${c.imageId}`);
       }
       case "network": {
@@ -122,6 +126,8 @@ export function installFakeDocker(daemonPort: number): FakeDocker {
       case "start": {
         const c = containers.get(rest[0]!);
         if (!c) return fail("Error: No such container");
+        if (c.network && !networks.has(c.network))
+          return fail(`Error response from daemon: failed to set up container networking: network ${c.network} not found`);
         c.running = true;
         return ok(rest[0]!);
       }