Files
zerto-ai-rewind/demo/windows_driver.py
T
justinandClaude Opus 5 3e7b777e53 demo: read the recovered content instead of a path
zerto_recover_file no longer writes the file to this host and hands back a
path, because a path here means nothing to a caller elsewhere and letting
the caller choose it was an arbitrary write. Both drivers still read
rec["path"], so they broke.

They now use the returned content. A small recovered_bytes() helper in each
driver decodes the text or base64 form, so the Windows copy-back keeps
shipping exact bytes rather than letting PowerShell rewrite line endings,
which is the bug that put a stray CR in an earlier take.

The Linux driver writes the bytes to a local file before scp, since scp
needs something on disk to send.

Verified against a live recovery: the helper returns 164 bytes whose sha256
matches the one the server reported, and the keys the on-screen show()
filter uses are all still present.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_016yVfC5nvZowoLFnEGWhLGn
2026-09-22 19:41:52 -04:00

205 lines
8.2 KiB
Python

"""Windows rewind demo. Beats hold for their narration length and log real start times."""
from __future__ import annotations
import json, os, sys, time
from pathlib import Path
import winrm
import diagram
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client
SP = Path(__file__).parent
CFG = json.loads((SP / "demo_win.json").read_text())
DUR = json.loads((SP / "vo" / "durations.json").read_text())
REPO = "/home/justin/github/zerto-ai-rewind"
MARKS = SP / "marks.jsonl"
PAD = 0.8 # breath between beats
RST, BOLD, DIM = "\033[0m", "\033[1m", "\033[2m"
CYAN, GREEN, RED, YEL, MAG = "\033[36m", "\033[32m", "\033[31m", "\033[33m", "\033[35m"
T0 = time.time()
STEP = [0]
def recovered_bytes(rec: dict) -> bytes:
"""zerto_recover_file returns the content now, not a path on the MCP host.
The server may be on another machine, so a path there is of no use here.
"""
import base64
if rec.get("encoding") == "base64":
return base64.b64decode(rec["content"])
return rec["content"].encode()
def w(s=""):
sys.stdout.write(s + "\n"); sys.stdout.flush()
def type_out(s, delay=0.018, color=""):
sys.stdout.write(color)
for ch in s:
sys.stdout.write(ch); sys.stdout.flush(); time.sleep(delay)
sys.stdout.write(RST + "\n"); sys.stdout.flush()
def begin(key, title=None):
"""Mark the beat start so the narration can be aligned to it later."""
t = time.time() - T0
with MARKS.open("a") as fh:
fh.write(json.dumps({"key": key, "t": round(t, 3)}) + "\n")
if title:
STEP[0] += 1
w(); w(f"{BOLD}{CYAN}{'=' * 74}{RST}")
type_out(f" STEP {STEP[0]} {title}", 0.010, BOLD + CYAN)
w(f"{BOLD}{CYAN}{'=' * 74}{RST}")
return t
def hold(start_t, key):
"""Keep this beat on screen until its narration has finished."""
want = DUR.get(key, 6.0) + PAD
spent = (time.time() - T0) - start_t
if spent < want:
time.sleep(want - spent)
def show(payload, keep=None, limit=18):
if keep:
payload = {k: payload[k] for k in keep if k in payload}
for line in json.dumps(payload, indent=2, default=str).splitlines()[:limit]:
w(f"{DIM} |{RST} {line}")
_sess = winrm.Session(f"http://{CFG['host']}:5985/wsman",
auth=(CFG["user"], CFG["password"]), transport="ntlm")
def guest_ps(ps, label):
w(f"{YEL} PS {CFG['host']}> {label}{RST}")
r = _sess.run_ps(ps)
out = r.std_out.decode(errors="replace").strip()
for line in out.splitlines():
w(f"{DIM} |{RST} {line}")
return out
async def main():
import asyncio
MARKS.unlink(missing_ok=True)
for n, key in enumerate(("i1", "i2", "i3", "i4"), start=1):
t = begin(key)
sys.stdout.write(diagram.frame(n)); sys.stdout.write("\n"); sys.stdout.flush()
hold(t, key)
params = StdioServerParameters(
command=f"{REPO}/.venv/bin/zerto-rewind-mcp",
env={**os.environ, "ZERTO_REWIND_CONFIG": f"{REPO}/config.json"})
devnull = open(os.devnull, "w")
async with stdio_client(params, errlog=devnull) as (r, s):
async with ClientSession(r, s) as sess:
t = begin("d1", "Connect to the rewind MCP")
await sess.initialize()
tools = await sess.list_tools()
w(f"{DIM} {len(tools.tools)} tools from zerto_rewind_mcp{RST}")
for x in tools.tools:
w(f"{DIM} - {x.name}{RST}")
hold(t, "d1")
async def call(name, **args):
w(f"{MAG} -> MCP call{RST} {BOLD}{name}{RST}")
for k, v in args.items():
w(f"{DIM} {k} = {v}{RST}")
res = await sess.call_tool(name, args)
return json.loads(res.content[0].text)
t = begin("d2", "The file the agent is about to break")
guest_ps(f"Get-Content '{CFG['guest_path']}'", f"Get-Content {CFG['guest_path']}")
hold(t, "d2")
t = begin("d3", "zerto_find_protection")
found = await call("zerto_find_protection", query=CFG["vm_query"])
show(found, keep=["ok", "outcome", "vm"])
if not found.get("ok"):
w(f"{RED} not ok, stopping{RST}"); return 1
hold(t, "d3")
t = begin("d4", "zerto_guard_before_mutate")
guard = await call("zerto_guard_before_mutate", query=CFG["vm_query"],
change_id=CFG["change_id"], agent="claude",
action=f"edit {CFG['guest_path']}")
show(guard, keep=["ok", "tag", "tagged"])
if not guard.get("ok"):
w(f"{RED} GUARD FAILED, refusing the change{RST}"); return 1
tg = guard["tagged"][0]
t_tag = time.strftime("%H:%M:%S")
w(f"{GREEN}{BOLD} checkpoint {tg['checkpoint_id']} inserted {t_tag} task={tg['task_state']}{RST}")
hold(t, "d4")
t = begin("d5", "Now the agent makes the bad change")
guest_ps(f"Set-Content -Path '{CFG['guest_path']}' -Value '{CFG['bad_content']}' -Encoding ASCII; "
f"Get-Content '{CFG['guest_path']}'", f"Set-Content {CFG['guest_path']} ...")
t_bad = time.strftime("%H:%M:%S")
w(f"{RED}{BOLD} the good config is gone from the guest ({t_bad}){RST}")
hold(t, "d5")
t = begin("d6", "zerto_recover_file without a human yes")
deny = await call("zerto_recover_file", vpg_identifier=CFG["vpg_id"],
vm_identifier=CFG["vm_identifier"],
checkpoint_identifier=tg["checkpoint_id"],
guest_path=CFG["guest_path"], confirmed=False)
show(deny)
w(f"{YEL} refused.{RST}")
hold(t, "d6")
t = begin("d7", "Human says yes: FLR from the pre-mutation checkpoint")
w(f"{BOLD} provenance{RST}")
w(f" {GREEN}cp {tg['checkpoint_id']} inserted {t_tag}{RST} {DIM}<- guard, BEFORE{RST}")
w(f" {RED}bad write {t_bad}{RST} {DIM}<- the mutation, AFTER{RST}")
rec = await call("zerto_recover_file", vpg_identifier=CFG["vpg_id"],
vm_identifier=CFG["vm_identifier"],
checkpoint_identifier=tg["checkpoint_id"],
guest_path=CFG["guest_path"], confirmed=True,
dest_dir=str(SP / "win_demo_out"))
show(rec, keep=["ok", "bytes", "flr_path", "unmount"])
if not rec.get("ok"):
w(f"{RED} FLR failed{RST}"); return 1
body = recovered_bytes(rec).decode()
w(f"{YEL} recovered file:{RST}")
for line in body.splitlines():
w(f"{GREEN}{BOLD} | {line}{RST}")
hold(t, "d7")
t = begin("d8", "Copy it back to the guest")
# Ship the recovered bytes verbatim. Set-Content rewrites line
# endings and appends one, which makes the restored file differ
# from what Zerto handed back. WriteAllBytes does not.
import base64
blob = recovered_bytes(rec)
b64 = base64.b64encode(blob).decode()
guest_ps(
f"[IO.File]::WriteAllBytes('{CFG['guest_path']}',"
f"[Convert]::FromBase64String('{b64}'));"
f"Get-Content '{CFG['guest_path']}';"
f"'md5: ' + (Get-FileHash '{CFG['guest_path']}' -Algorithm MD5).Hash",
f"WriteAllBytes {CFG['guest_path']} <{len(blob)} recovered bytes>")
hold(t, "d8")
t = begin("d9")
w(); w(f"{BOLD}{YEL} the same checkpoint, bigger blast radius{RST}")
type_out(" one file -> file level recovery (what you just saw)", 0.012, DIM)
type_out(" the whole VM -> offsite clone, failover test, or failover", 0.012, DIM)
hold(t, "d9")
t = begin("d10")
w(); w(f"{BOLD}{GREEN}{'=' * 74}{RST}")
type_out(" REWOUND. The recovery point was the journal.", 0.018, BOLD + GREEN)
w(f"{BOLD}{GREEN}{'=' * 74}{RST}")
hold(t, "d10")
return 0
import asyncio
sys.exit(asyncio.run(main()))