feat: add openstack to nix (#7519)

* feat: add openstack to nix

* fix: note about FSH

I since moved away from an FSH into a regular env

* refactor: use venvShellHook

This is not as robust as the existing hook — it doesn't hash the
interpreter, but that's OK.

Author: agoose77

flake.nix

@@ -1,5 +1,5 @@
 # code-owner: @agoose77
-# This flake sets up an FSH dev-shell that installs all the required
+# This flake sets up a dev-shell that installs all the required
 # packages for running deployer, and then installs the tool in the virtual environment
 # It is not best-practice for the nix-way of distributing this code,
 # but its purpose is to get an environment up and running.
@@ -23,10 +23,18 @@
       gdk = pkgs.google-cloud-sdk.withExtraComponents (with pkgs.google-cloud-sdk.components; [
         gke-gcloud-auth-plugin
       ]);
+      openstack = python.pkgs.toPythonApplication (
+        python.pkgs.python-openstackclient.overridePythonAttrs (oldAttrs: {
+          dependencies =
+            (oldAttrs.dependencies or [])
+            ++ [python.pkgs.python-magnumclient];
+        })
+      );
       python = pkgs.python313;
       packages =
         [
           python
+          python.pkgs.venvShellHook
         ]
         ++ (with pkgs; [
           cmake
@@ -43,46 +51,26 @@
           awscli2
           azure-cli
           terraform
+          openstack
           eksctl
         ]);
-      shellHook = ''
-        # Unset leaky PYTHONPATH
-        unset PYTHONPATH
-
-        __hash=$(echo ${python.interpreter} | sha256sum)
-
-        # Setup if not defined ####
-        if [[ ! -f ".venv/$__hash" ]]; then
-            __setup_env() {
-                # Remove existing venv
-                if [[ -d .venv ]]; then
-                    rm -r .venv
-                fi
-
-                # Stand up new venv
-                ${python.interpreter} -m venv .venv
-
-                ".venv/bin/python" -m pip install -e ".[dev]"
-
-                # Add a marker that marks this venv as "ready"
-                touch ".venv/$__hash"
-            }
-
-            __setup_env
-        fi
-        ###########################
-
-        # Activate venv
-        source .venv/bin/activate
-      '';
       env = lib.optionalAttrs pkgs.stdenv.isLinux {
         # Python uses dynamic loading for certain libraries.
         # We'll set the linker path instead of patching RPATH
         LD_LIBRARY_PATH = lib.makeLibraryPath pkgs.pythonManylinuxPackages.manylinux2014;
       };
     in {
       devShell = pkgs.mkShell {
-        inherit env packages shellHook;
+        inherit env packages;
+
+        venvDir = "./.venv";
+        postShellHook = ''
+          unset SOURCE_DATE_EPOCH PYTHONPATH
+        '';
+        postVenvCreation = ''
+          unset SOURCE_DATE_EPOCH PYTHONPATH
+          pip install -e ".[dev]"
+        '';
       };
     });
 }