cloud: one-command dev loop on a kept Cloud machine (build, patch-push, restart, journey in about a minute)

scripts/cmux-next/cloud-dev-loop.sh

@@ -11,6 +11,8 @@
 #    development config; with step 1 its PLATFORM binding and CLOUD_DO point at that platform preview).
 # 3. Runs `bun scripts/cmux-next/cloud-journey.ts --backend preview-<tag>` with the words after `--`.
 # Each part's seconds and the total are printed at the end (the loop time this exists to keep small).
+# Machine-side changes (cmux-tui, cmux-host, acpmux) iterate on one kept Cloud machine instead:
+# scripts/cmux-next/cloud-devloop.ts (build on fleet Linux, patch-push, restart, journey on that machine).
 #
 # Needs: the cf CLI signed in (deploy-worker.sh reads its OAuth token) or CLOUDFLARE_API_TOKEN;
 # ~/.secrets/cmux-next-api-preview.env (JWT_PRIVATE_JWK), as for any preview; the agent test account in
@@ -26,7 +28,7 @@ while [ $# -gt 0 ]; do
     --no-deploy) deploy=0; shift ;;
     --credentials) creds="$2"; shift 2 ;;
     --) shift; break ;;
-    -h|--help) sed -n '2,20p' "$0"; exit 0 ;;
+    -h|--help) sed -n '2,22p' "$0"; exit 0 ;;
     *) echo "unknown argument $1 (journey arguments go after --)" >&2; exit 2 ;;
   esac
 done

scripts/cmux-next/cloud-devloop.test.ts

@@ -0,0 +1,64 @@
+import { describe, expect, test } from "bun:test";
+import { spawnSync } from "node:child_process";
+import { changedFiles, guestInstallScript, guestRestoreScript, PIECE_BYTES, remotePrepareScript, uploadPieces } from "./cloud-devloop";
+import { keyedHoldProblem } from "./cloud-journey";
+
+const bashParses = (script: string) => spawnSync("bash", ["-n"], { input: script, encoding: "utf8" });
+
+describe("cloud devloop", () => {
+  test("changed files: modified, added, renamed and untracked are copied; deleted and renamed-from are removed", () => {
+    const files = changedFiles("M\tcmux-tui/a.rs\nA\tcmux-tui/b.rs\nD\tcmux-tui/c.rs\nR087\tcmux-tui/old.rs\tcmux-tui/new.rs\n", "scripts/x.ts\n\n");
+    expect(files.copy).toEqual(["cmux-tui/a.rs", "cmux-tui/b.rs", "cmux-tui/new.rs", "scripts/x.ts"]);
+    expect(files.removed).toEqual(["cmux-tui/c.rs", "cmux-tui/old.rs"]);
+  });
+
+  test("a file both deleted and untracked again is copied, not removed", () => {
+    expect(changedFiles("D\tf.rs\n", "f.rs\n")).toEqual({ copy: ["f.rs"], removed: [] });
+  });
+
+  test("the build host, guest install and restore scripts are valid bash and quote what they are given", () => {
+    for (const s of [
+      remotePrepareScript("0123456789abcdef0123456789abcdef01234567", ["it's gone.rs"]),
+      guestInstallScript("a".repeat(64), "patch", ["host", "acpmux"]),
+      guestInstallScript("b".repeat(64), "full", []),
+      guestRestoreScript(["host"]),
+    ]) {
+      const r = bashParses(s);
+      expect(r.stderr).toBe("");
+      expect(r.status).toBe(0);
+    }
+    expect(remotePrepareScript("abc", ["it's gone.rs"])).toContain(`rm -f -- 'it'\\''s gone.rs'`);
+  });
+
+  test("install checks the build's SHA-256 before anything moves, flips current in one rename, restarts only what it is told", () => {
+    const s = guestInstallScript("c".repeat(64), "patch", ["acpmux"]);
+    expect(s.indexOf("sha256sum -c")).toBeLessThan(s.indexOf("mv -f new.bin"));
+    expect(s).toContain("--patch-from=current.bin");
+    expect(s).toContain("mv -Tf /opt/cmux/current.devloop /opt/cmux/current");
+    expect(s).toContain("systemctl --user restart acpmux.service");
+    expect(s).not.toContain("cmux-host.service");
+  });
+
+  test("uploads in pieces under the 768 KiB machine write limit, in order, retrying a failed piece", async () => {
+    const data = new Uint8Array(PIECE_BYTES * 2 + 10).map((_, i) => i % 251);
+    const seen = new Map<string, number>();
+    let failOnce = true;
+    const cloud = {
+      write: async (_m: string, file: string, bytes: Uint8Array) => {
+        if (failOnce && file.endsWith("00001")) { failOnce = false; throw new Error("HTTP 502"); }
+        expect(bytes.byteLength).toBeLessThan(768 * 1024);
+        seen.set(file, bytes.byteLength);
+      },
+    };
+    expect(await uploadPieces(cloud, "vm_x", "/d", data, 2)).toBe(3);
+    expect([...seen.keys()].sort()).toEqual(["/d/00000", "/d/00001", "/d/00002"]);
+    expect(seen.get("/d/00002")).toBe(10);
+  });
+
+  test("keyed hold: an unkeyed daemon, another keyed run or none at all is named; the start's own daemon passes", () => {
+    expect(keyedHoldProblem("i1", { pid: 7, personKey: true, personInstance: "i1" })).toBeNull();
+    expect(keyedHoldProblem("i1", { pid: 8, personInstance: "i2" })).toContain("unkeyed daemon took the socket");
+    expect(keyedHoldProblem("i1", { pid: 8, personKey: true, personInstance: "i2" })).toContain("another keyed daemon");
+    expect(keyedHoldProblem("i1", { running: false })).toContain("no daemon serves");
+  });
+});