Call conda more resiliently

tljh/systemd.py

@@ -0,0 +1,59 @@
+"""
+Wraps systemctl to install, uninstall, start & stop systemd services.
+
+We use sudo + subprocess calls for everything. This works when we
+are running as root & as normal user (with arbitrary sudo privileges).
+Arbitrary sudo privileges suck, but are better than running the whole
+process as root.
+
+If we use a debian package instead, we can get rid of all this code.
+"""
+import subprocess
+import os
+
+
+def reload_daemon():
+    """
+    Equivalent to systemctl daemon-reload.
+
+    Makes systemd discover new units.
+    """
+    subprocess.run([
+        'sudo',
+        'systemctl',
+        'daemon-reload'
+    ], check=True)
+
+
+def install_unit(name, unit, path='/etc/systemd/system'):
+    """
+    Install unit wih given name
+    """
+    subprocess.run([
+        'sudo',
+        'tee',
+        os.path.join(path, name)
+    ], input=unit.encode('utf-8'), check=True)
+
+
+def uninstall_unit(name, path='/etc/systemd/system'):
+    """
+    Uninstall unit with given name
+    """
+    subprocess.run([
+        'sudo',
+        'rm',
+        os.path.join(path, name)
+    ], check=True)
+
+
+def start_service(name):
+    """
+    Start service with given name.
+    """
+    subprocess.run([
+        'sudo',
+        'systemctl',
+        'start',
+        name
+    ], check=True)