Make sure the charm can be installed bionic

requirements.txt

@@ -1,5 +1,5 @@
 charmhelpers
-packaging
+packaging < 22.0 # make sure this works on all [email protected], [email protected], and [email protected],
 # pin ops framework version to
 # support bionic deployments
 ops >= 1.5.0,< 2.0.0

src/charm.py

@@ -192,7 +192,7 @@ def get_controller_version(self) -> version.Version:
         if not controller_version:
             raise RuntimeError("Charm failed to fetch controller's version.")
 
-        return version.parse(controller_version)
+        return version.Version(controller_version)
 
     def get_controller_ca_cert(self) -> str:
         """Get CA certificate used by targeted Juju controller.

src/exporter.py

@@ -56,7 +56,7 @@ def controller_endpoint(self) -> Union[str, List[str]]:
         endpoints: Union[str, List[str]] = self.controller.split(",")
         current_version = ExporterSnap.version()
 
-        if current_version <= version.parse("1.0.1"):
+        if current_version <= version.Version("1.0.1"):
             if len(endpoints) > 1:
                 raise ExporterConfigError(
                     f"Currently installed version of exporter ({current_version}) does "
@@ -231,7 +231,7 @@ def version(cls) -> version.Version:
             raise ExporterSnapError("Exporter snap is not installed.")
 
         snap_version = snap_info["installed"].split()[0]
-        return version.parse(snap_version)
+        return version.Version(snap_version)
 
     def restart(self) -> None:
         """Restart exporter service."""

tox.ini

@@ -28,15 +28,13 @@ passenv =
   TEST_*
 
 [testenv:dev-environment]
-envdir = {toxinidir}/.venv
 deps =
   pre-commit
   {[testenv:lint]deps}
   {[testenv:unit]deps}
   {[testenv:func]deps}
 
 [testenv:pre-commit]
-envdir = {[testenv:dev-environment]envdir}
 deps = {[testenv:dev-environment]deps}  # ensure that dev-environment is installed
 commands = pre-commit run --all-files
 
@@ -62,7 +60,6 @@ deps =
     {[testenv:func]deps}
 
 [testenv:reformat]
-envdir = {toxworkdir}/lint
 commands =
     black .
     isort .