fix: use RWO for single-replica Longhorn volumes

tests/lib/convert-storage-env.test.ts

@@ -38,6 +38,7 @@ describe("volume conversion", () => {
     expect(claims[0]).toMatchObject({
       metadata: { name: "project-data", namespace: "project" },
       spec: {
+        accessModes: ["ReadWriteMany"],
         resources: { requests: { storage: "1Gi" } },
         storageClassName: expect.stringMatching(
           /^kuber-longhorn-[a-f0-9]{12}$/,
@@ -64,6 +65,16 @@ describe("volume conversion", () => {
     ]);
   });
 
+  test("renders single-replica Longhorn volumes as ReadWriteOnce", () => {
+    const service = { volumes: ["data(20Gi on 1 fast):/data"] } as Service;
+    const [claim] = volumesToPvc("project", service);
+    const [storageClass] = volumesToStorageClasses(service);
+
+    expect(claim?.spec?.accessModes).toEqual(["ReadWriteOnce"]);
+    expect(claim?.spec?.storageClassName).toBe(storageClass?.metadata?.name);
+    expect(storageClass?.parameters?.numberOfReplicas).toBe("1");
+  });
+
   test("parses inline storage sizing and placement", () => {
     const [claim] = volumesToPvc("project", {
       volumes: ["data(20Gi on 3 fast,archive):/data"],
@@ -71,6 +82,7 @@ describe("volume conversion", () => {
     expect(claim).toMatchObject({
       metadata: { name: "project-data" },
       spec: {
+        accessModes: ["ReadWriteMany"],
         resources: { requests: { storage: "20Gi" } },
         storageClassName: expect.stringMatching(/^kuber-longhorn-/),
       },
@@ -103,11 +115,29 @@ describe("volume conversion", () => {
       } as ComposeSpecification["volumes"],
     );
     expect(claim?.spec).toMatchObject({
+      accessModes: ["ReadWriteMany"],
       resources: { requests: { storage: "50Gi" } },
       storageClassName: expect.stringMatching(/^kuber-longhorn-/),
     });
   });
 
+  test("uses top-level single-replica policy for the PVC and StorageClass", () => {
+    const service = { volumes: ["data:/data"] } as Service;
+    const volumes = {
+      data: { "x-replicaCount": 1 },
+    } as ComposeSpecification["volumes"];
+    const [claim] = volumesToPvc("project", service, process.cwd(), volumes);
+    const [storageClass] = volumesToStorageClasses(
+      service,
+      process.cwd(),
+      volumes,
+    );
+
+    expect(claim?.spec?.accessModes).toEqual(["ReadWriteOnce"]);
+    expect(claim?.spec?.storageClassName).toBe(storageClass?.metadata?.name);
+    expect(storageClass?.parameters?.numberOfReplicas).toBe("1");
+  });
+
   test("does not create PVCs for anonymous, tmpfs, or managed claims", () => {
     expect(
       volumesToPvc("project", {