Add migration to selfprivacy nix channel

selfprivacy_api/app.py

@@ -68,7 +68,7 @@ def create_app(test_config=None):
     def spec():
         if app.config["ENABLE_SWAGGER"] == "1":
             swag = swagger(app)
-            swag["info"]["version"] = "1.2.2"
+            swag["info"]["version"] = "1.2.3"
             swag["info"]["title"] = "SelfPrivacy API"
             swag["info"]["description"] = "SelfPrivacy API"
             swag["securityDefinitions"] = {

selfprivacy_api/migrations/migrate_to_selfprivacy_channel.py

@@ -0,0 +1,47 @@
+import os
+import subprocess
+
+from selfprivacy_api.migrations.migration import Migration
+
+
+class MigrateToSelfprivacyChannel(Migration):
+    def get_migration_name(self):
+        return "migrate_to_selfprivacy_channel"
+
+    def get_migration_description(self):
+        return "Migrate to selfprivacy Nix channel."
+
+    def is_migration_needed(self):
+        try:
+            output = subprocess.check_output(
+                ["nix-channel", "--list"], start_new_session=True
+            )
+            output = output.decode("utf-8")
+            first_line = output.split("\n", maxsplit=1)[0]
+            return first_line.startswith("nixos") and (
+                first_line.endswith("nixos-21.11") or first_line.endswith("nixos-21.05")
+            )
+        except subprocess.CalledProcessError:
+            return False
+        return False
+
+    def migrate(self):
+        # Change the channel and update them.
+        # Also, go to /etc/nixos directory and make a git pull
+        current_working_directory = os.getcwd()
+        try:
+            os.chdir("/etc/nixos")
+            subprocess.check_output(
+                [
+                    "nix-channel",
+                    "--add",
+                    "https://channel.selfprivacy.org/nixos-selfpricacy",
+                    "nixos",
+                ]
+            )
+            subprocess.check_output(["nix-channel", "--update"])
+            subprocess.check_output(["git", "pull"])
+            os.chdir(current_working_directory)
+        except subprocess.CalledProcessError:
+            os.chdir(current_working_directory)
+            print("Error")

selfprivacy_api/resources/common.py

@@ -23,4 +23,4 @@ class ApiVersion(Resource):
             401:
                 description: Unauthorized
         """
-        return {"version": "1.2.2"}
+        return {"version": "1.2.3"}

setup.py

@@ -2,7 +2,7 @@ from setuptools import setup, find_packages
 
 setup(
     name="selfprivacy_api",
-    version="1.2.2",
+    version="1.2.3",
     packages=find_packages(),
     scripts=[
         "selfprivacy_api/app.py",