Faketime work

README.md

@@ -38,6 +38,12 @@ The preferred way is via `runner/runc.sh`, which builds a container image and ru
 ./runner/runc.sh ./runner/regression.sh
 ```
 
+Run with clock skew on one pool node:
+
+```sh
+./runner/runc.sh -- TIME_DRIFT_POOL=1 TIME_DRIFT_SPEC='+0 x1.008' ./runner/regression.sh
+```
+
 Run a specific test:
 
 ```sh
@@ -167,6 +173,9 @@ You can fine-tune test runs using these environment variables:
 | `TX_CENTRIFUGE_REV`| `tx-centrifuge` version (default: `bench/leios-11.0.1`) |
 | `PYTEST_ARGS`      | Extra options passed to pytest.                         |
 | `TEST_THREADS`     | Number of pytest workers (default: `20`).               |
+| `TIME_DRIFT_POOL`  | Pool (1-3) for libfaketime clock skew; unset = off.     |
+| `TIME_DRIFT_SPEC`  | libfaketime `FAKETIME` string, e.g. `+0 x1.008`.        |
+| `LIBFAKETIME_PATH` | Override path to `libfaketimeMT.so.1`.                  |
 
 ### 💡 Usage Examples
 

cardano_node_tests/utils/cluster_scripts.py

@@ -74,6 +74,48 @@ def get_testnet_variant_scriptdir2(*, testnet_variant: str) -> pl.Path:
     return scriptdir
 
 
+_TIME_DRIFT_HOOK = """\
+# TIME_DRIFT: activate clock skew on this pool when TIME_DRIFT_POOL=%%POOL_NUM%%
+if [[ -n "${TIME_DRIFT_POOL:-}" && -n "${TIME_DRIFT_SPEC:-}" \\
+      && "${TIME_DRIFT_POOL}" == "%%POOL_NUM%%" ]]; then
+  _ft_so="${LIBFAKETIME_PATH:-/usr/lib/x86_64-linux-gnu/faketime/libfaketimeMT.so.1}"
+  if [[ ! -f "$_ft_so" ]]; then
+    _ft_bin="$(command -v faketime 2>/dev/null || true)"
+    if [[ -n "$_ft_bin" ]]; then
+      _ft_so="$(dirname "$(dirname "$_ft_bin")")/lib/faketime/libfaketimeMT.so.1"
+    fi
+  fi
+  if [[ ! -f "$_ft_so" ]]; then
+    echo "[faketime] ERROR: libfaketimeMT.so.1 not found" >&2
+    exit 1
+  fi
+  export LD_PRELOAD="${LD_PRELOAD:+${LD_PRELOAD}:}$_ft_so"
+  export FAKETIME="${TIME_DRIFT_SPEC}"
+  echo "[faketime] pool%%POOL_NUM%%: LD_PRELOAD=$LD_PRELOAD FAKETIME=$FAKETIME" >&2
+fi
+"""
+
+
+def _inject_time_drift_hook(content: str, pool_num: int) -> str:
+    """Inject a conditional clock-skew bash block into pool wrapper scripts.
+
+    Appends after the pre-run setup placeholder in the cardonnay template, leaving
+    the placeholder itself intact. Activated only when TIME_DRIFT_POOL=<pool_num>
+    and TIME_DRIFT_SPEC are set at cluster start time. Default-off: unset env vars
+    leave behaviour unchanged.
+
+    Raises:
+        ValueError: When the pre-run setup placeholder is absent from the template.
+    """
+    marker = "# --- Placeholder for any pre-run setup ---"
+    if marker not in content:
+        msg = f"TIME_DRIFT hook: pre-run placeholder missing in pool{pool_num} wrapper."
+        raise ValueError(msg)
+
+    hook = _TIME_DRIFT_HOOK.replace("%%POOL_NUM%%", str(pool_num))
+    return content.replace(marker, f"{marker}\n{hook.rstrip(chr(10))}", 1)
+
+
 class CustomCardonnayScripts(cardonnay_local.LocalScripts):
     """Scripts for starting local cluster.
 
@@ -187,6 +229,9 @@ def _reconfigure_local(self, indir: pl.Path, destdir: pl.Path, instance_num: int
                     node_rec=node_rec,
                     instance_num=instance_num,
                 )
+                supervisor_script_content = _inject_time_drift_hook(
+                    content=supervisor_script_content, pool_num=node_rec.num
+                )
                 supervisor_script.unlink(missing_ok=True)
                 supervisor_script.write_text(f"{supervisor_script_content}\n", encoding="utf-8")
                 supervisor_script.chmod(0o755)

flake.nix

@@ -46,6 +46,7 @@
                 nodePkgs.bech32
                 nodePkgs.tx-generator
                 centrifugePkgs.tx-centrifuge
+                pkgs.libfaketime
                 pkgs.bashInteractive
               ];
             };