fix(systemd): consider the unit to be active

in order to not mislead the end user once the main process is gone.

Signed-off-by: Joel Capitao <jcapitao@redhat.com>
Co-authored-by: Carlos Eduardo Arango Gutierrez <eduardoa@nvidia.com>

Author: joelcapitao

deployments/systemd/nvidia-cdi-refresh.service

@@ -26,6 +26,7 @@ EnvironmentFile=-/etc/nvidia-container-toolkit/nvidia-cdi-refresh.env
 ExecCondition=/usr/bin/grep -qE '/nvidia.ko' /lib/modules/%v/modules.dep
 ExecStart=/usr/bin/nvidia-ctk cdi generate
 CapabilityBoundingSet=CAP_SYS_MODULE CAP_SYS_ADMIN CAP_MKNOD
+RemainAfterExit=yes
 
 [Install]
 WantedBy=multi-user.target

tests/e2e/nvidia-cdi-refresh_test.go

@@ -97,12 +97,23 @@ EOF
 	# remove the generated files
 	rm /var/run/cdi/nvidia.yaml /tmp/nvidia.yaml
 
-	# Touch the nvidia-ctk binary to change the mtime
-	# This will trigger the nvidia-cdi-refresh.path unit to call the
-	# nvidia-cdi-refresh.service unit, simulating a change(update/downgrade) in the nvidia-ctk binary.
-	touch $(which nvidia-ctk)
-
-	# wait for 3 seconds
+        # Simulate a binary upgrade by removing and recreating the file
+        # This mimics package manager behavior during upgrades
+        NVIDIA_CTK_PATH=$(which nvidia-ctk)
+        # Create a backup
+        cp "${NVIDIA_CTK_PATH}" "${NVIDIA_CTK_PATH}.backup"
+        # Remove the original (simulating uninstall/upgrade phase)
+        rm -f "${NVIDIA_CTK_PATH}"
+        # Small delay to ensure systemd detects the removal
+        sleep 0.1
+        # Restore from backup (simulating install phase)
+        cp "${NVIDIA_CTK_PATH}.backup" "${NVIDIA_CTK_PATH}"
+        # Ensure executable permissions
+        chmod +x "${NVIDIA_CTK_PATH}"
+        # Clean up backup
+        rm -f "${NVIDIA_CTK_PATH}.backup"
+
+        # wait for systemd path unit to detect the change and trigger the service
 	sleep 3
 
 	# Check if the file /var/run/cdi/nvidia.yaml is created