Check version of LTTng Python module and raise error if below 2.10.7

tracetools_trace/tracetools_trace/tools/lttng.py

@@ -23,6 +23,15 @@ try:
     from . import lttng_impl
 
     _lttng = lttng_impl
+
+    # Check lttng module version
+    from distutils.version import StrictVersion
+    current_version = _lttng.get_version()
+    LTTNG_MIN_VERSION = '2.10.7'
+    if current_version is None or current_version < StrictVersion(LTTNG_MIN_VERSION):
+        raise RuntimeError(
+            f'lttng module version >={LTTNG_MIN_VERSION} required, found {str(current_version)}'
+        )
 except ImportError:
     # Fall back on stub functions so that this still passes linter checks
     from . import lttng_stub

tracetools_trace/tracetools_trace/tools/lttng_impl.py

@@ -14,8 +14,11 @@
 
 """Implementation of the interface for tracing with LTTng."""
 
+from distutils.version import StrictVersion
+import re
 from typing import List
 from typing import Optional
+from typing import Union
 
 import lttng
 
@@ -26,6 +29,23 @@ from .path import DEFAULT_BASE_PATH
 from .path import get_full_session_path
 
 
+def get_version() -> Union[StrictVersion, None]:
+    """
+    Get the version of the lttng module.
+
+    The module does not have a __version__ attribute, but the version is mentioned in its __doc__,
+    and seems to be written in a consistent way across versions.
+
+    :return: the version as a StrictVersion object, or `None` if it cannot be extracted
+    """
+    doc_lines = lttng.__doc__.split('\n')
+    first_line = list(filter(None, doc_lines))[0]
+    version_string = first_line.split(' ')[1]
+    if not re.compile(r'^[0-9]+\.[0-9]+\.[0-9]+$').match(version_string):
+        return None
+    return StrictVersion(version_string)
+
+
 def setup(
     session_name: str,
     base_path: str = DEFAULT_BASE_PATH,