From 8d19cf159f19a6b02c66badc9eab39d451934f75 Mon Sep 17 00:00:00 2001
From: checktheroads <matt@allroads.io>
Date: Mon, 30 Dec 2019 23:00:53 -0700
Subject: [PATCH] bump min Python version to 3.7; check python version at start

---
 hyperglass/constants.py  |  2 ++
 hyperglass/hyperglass.py |  8 ++++++++
 hyperglass/util.py       | 18 ++++++++++++++++++
 setup.py                 |  6 +++---
 4 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/hyperglass/constants.py b/hyperglass/constants.py
index 84e0f58..b24db16 100644
--- a/hyperglass/constants.py
+++ b/hyperglass/constants.py
@@ -2,6 +2,8 @@
 # Standard Library Imports
 import sys
 
+MIN_PYTHON_VERSION = (3, 7)
+
 protocol_map = {80: "http", 8080: "http", 443: "https", 8443: "https"}
 
 target_format_space = ("huawei", "huawei_vrpv8")
diff --git a/hyperglass/hyperglass.py b/hyperglass/hyperglass.py
index a78a00f..0458bd6 100644
--- a/hyperglass/hyperglass.py
+++ b/hyperglass/hyperglass.py
@@ -39,9 +39,17 @@ from hyperglass.exceptions import ResponseEmpty
 from hyperglass.exceptions import RestError
 from hyperglass.exceptions import ScrapeError
 from hyperglass.render import render_html
+from hyperglass.util import check_python
 from hyperglass.util import cpu_count
 from hyperglass.util import log
 
+# Verify Python version meets minimum requirement
+try:
+    python_version = check_python()
+    log.info(f"Python {python_version} detected.")
+except RuntimeError as r:
+    raise HyperglassError(str(r), alert="danger") from None
+
 log.debug(f"Configuration Parameters: {params.dict(by_alias=True)}")
 
 tempdir = tempfile.TemporaryDirectory(prefix="hyperglass_")
diff --git a/hyperglass/util.py b/hyperglass/util.py
index 02a921c..a582003 100644
--- a/hyperglass/util.py
+++ b/hyperglass/util.py
@@ -24,4 +24,22 @@ def cpu_count():
     return multiprocessing.cpu_count()
 
 
+def check_python():
+    """Verify Python Version.
+
+    Raises:
+        RuntimeError: Raised if running Python version is invalid.
+
+    Returns:
+        {str} -- Python version
+    """
+    import sys
+    from hyperglass.constants import MIN_PYTHON_VERSION
+
+    pretty_version = ".".join(tuple(str(v) for v in MIN_PYTHON_VERSION))
+    if sys.version_info < MIN_PYTHON_VERSION:
+        raise RuntimeError(f"Python {pretty_version}+ is required.")
+    return pretty_version
+
+
 log = _logger()
diff --git a/setup.py b/setup.py
index c545a1d..3ef1b3b 100644
--- a/setup.py
+++ b/setup.py
@@ -2,8 +2,8 @@
 import sys
 from distutils.core import setup
 
-if sys.version_info < (3, 6):
-    sys.exit("Python 3.6+ is required.")
+if sys.version_info < (3, 7):
+    sys.exit("Python 3.7+ is required.")
 
 
 with open("README.md", "r") as ld:
@@ -21,7 +21,7 @@ setup(
     author_email="matt@hyperglass.io",
     description=desc,
     url="https://github.com/checktheroads/hyperglass",
-    python_requires=">=3.6",
+    python_requires=">=3.7",
     packages=["hyperglass"],
     install_requires=requirements,
     license="BSD 3-Clause Clear License",