Cover live sshd in e2e without breaking CI

.github/workflows/ci.yml

@@ -133,3 +133,6 @@ jobs:
         run: make build
       - name: Round trip a synthetic model over the local and SSH transports
         run: ./scripts/e2e.sh
+      - name: Round trip over live sshd (skips when localhost SSH is unavailable)
+        if: matrix.os == 'ubuntu-latest'
+        run: ./scripts/e2e-live.sh

AGENTS.md

@@ -28,19 +28,15 @@ make build
 
 `make check` runs fmt-check, vet, lint, and test (not race, cover, or e2e).
 
-After any change that touches copy/sync/verify/SSH, also run a **live
-sshd** round trip on this machine (not the fake SSH in `scripts/e2e.sh`):
+After any change that touches copy/sync/verify/SSH, also run the live
+sshd smoke (skips when `ubuntu@127.0.0.1` is unreachable):
 
 ```sh
 make build
-SRC=$(mktemp -d); DST=/tmp/modelmove-live-dst
-# build a tiny HF-shaped tree in $SRC, then:
-./bin/modelmove copy "$SRC" "ubuntu@127.0.0.1:$DST" --remote-bin "$PWD/bin/modelmove" --no-progress
-./bin/modelmove verify "$DST" --no-progress
+./scripts/e2e.sh
+./scripts/e2e-live.sh
 ```
 
-Localhost SSH must work as `ubuntu@127.0.0.1` without a password.
-
 ## Layout
 
 | Path | Role |

Makefile

@@ -70,6 +70,14 @@ fmt-check: ## Fail if the tree is not formatted
 tidy: ## Tidy go.mod
 	go mod tidy
 
+.PHONY: e2e
+e2e: build ## Local + fake-SSH smoke
+	./scripts/e2e.sh
+
+.PHONY: e2e-live
+e2e-live: build ## Live sshd smoke (skips if ubuntu@127.0.0.1 is unreachable)
+	./scripts/e2e-live.sh
+
 .PHONY: check
 check: fmt-check vet lint test ## Everything CI runs
 

scripts/e2e-live.sh

@@ -0,0 +1,85 @@
+#!/usr/bin/env bash
+# Live-sshd smoke: same synthetic HF tree as e2e.sh, but the destination is
+# ubuntu@127.0.0.1 over a real sshd. Skips cleanly when localhost SSH is
+# unavailable so GitHub Actions and laptops without sshd stay green.
+set -euo pipefail
+
+BIN=${BIN:-"$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)/bin/modelmove"}
+if [ ! -x "$BIN" ]; then
+  echo "e2e-live: $BIN not found; run 'make build' first" >&2
+  exit 1
+fi
+
+REMOTE_USER=${MODELMOVE_LIVE_SSH_USER:-ubuntu}
+REMOTE_HOST=${MODELMOVE_LIVE_SSH_HOST:-127.0.0.1}
+SSH=(ssh -o BatchMode=yes -o ConnectTimeout=2 -o StrictHostKeyChecking=accept-new)
+
+if ! "${SSH[@]}" "${REMOTE_USER}@${REMOTE_HOST}" true >/dev/null 2>&1; then
+  echo "e2e-live: skip (no live ssh to ${REMOTE_USER}@${REMOTE_HOST})"
+  exit 0
+fi
+
+WORK=$(mktemp -d)
+trap 'rm -rf "$WORK"; "${SSH[@]}" "${REMOTE_USER}@${REMOTE_HOST}" "rm -rf /tmp/modelmove-live-$$" >/dev/null 2>&1 || true' EXIT
+
+REMOTE_DST="/tmp/modelmove-live-$$"
+SRC="$WORK/src"
+mkdir -p "$SRC"
+
+echo "==> e2e-live: synthetic Hugging Face checkpoint"
+python3 - "$SRC" <<'PY'
+import os, random, sys
+root = sys.argv[1]
+random.seed(1234)
+with open(os.path.join(root, "config.json"), "w") as f:
+    f.write('{"model_type":"llama","hidden_size":4096}')
+with open(os.path.join(root, "tokenizer.json"), "w") as f:
+    f.write('{"vocab":[]}' + "x" * 20000)
+with open(os.path.join(root, "model.safetensors.index.json"), "w") as f:
+    f.write('{"weight_map":{}}')
+for i in (1, 2):
+    name = f"model-0000{i}-of-00002.safetensors"
+    with open(os.path.join(root, name), "wb") as f:
+        f.write(random.randbytes(4_000_000))
+PY
+
+fail() { echo "e2e-live: $1" >&2; exit 1; }
+
+TARGET="${REMOTE_USER}@${REMOTE_HOST}:${REMOTE_DST}"
+
+echo "==> e2e-live: copy over live sshd"
+"$BIN" copy "$SRC" "$TARGET" --remote-bin "$BIN" --no-progress
+"${SSH[@]}" "${REMOTE_USER}@${REMOTE_HOST}" "'$BIN' verify '$REMOTE_DST' --no-progress"
+
+echo "==> e2e-live: unchanged resync should move nothing"
+"$BIN" sync "$SRC" "$TARGET" --remote-bin "$BIN" --json --no-progress > "$WORK/noop.json"
+python3 - "$WORK/noop.json" <<'PY'
+import json, sys
+r = json.load(open(sys.argv[1]))
+sent = r["summary"]["bytes_received"]
+assert sent == 0, f"an unchanged resync sent {sent} bytes"
+PY
+
+echo "==> e2e-live: sparse update after a small edit"
+python3 - "$SRC/model-00001-of-00002.safetensors" <<'PY'
+import sys
+p = sys.argv[1]
+d = bytearray(open(p, "rb").read())
+d[2_000_000:2_000_064] = b"FINETUNED" * 7 + b"!"
+open(p, "wb").write(bytes(d))
+PY
+
+"$BIN" sync "$SRC" "$TARGET" --remote-bin "$BIN" --json --no-progress > "$WORK/delta.json"
+python3 - "$WORK/delta.json" <<'PY'
+import json, sys
+r = json.load(open(sys.argv[1]))
+total = r["plan"]["total_bytes"]
+sent = r["summary"]["bytes_received"]
+assert sent < total // 8, f"a 64-byte edit moved {sent} of {total} bytes"
+print(f"    live ssh: moved {sent} of {total} bytes")
+PY
+
+"${SSH[@]}" "${REMOTE_USER}@${REMOTE_HOST}" "'$BIN' verify '$REMOTE_DST' --no-progress"
+
+echo
+echo "e2e-live: all checks passed"