Fixing `systemctl --user Is-failed` Reporting Errors

Oct 20, 2025 by ADMIN 53 views

Have you ever encountered a situation where systemctl --user is-failed gives you the wrong status for a service? It's a frustrating issue, especially when you're trying to debug systemd services. Let's dive into a specific case and explore how to tackle it.

Understanding the Issue

When using systemd, the systemctl --user is-failed command should accurately report whether a service has failed. However, sometimes, particularly with oneshot services, it might show an inactive state instead of failed, leading to confusion and potential troubleshooting headaches.

The Problem in Detail

Consider a scenario where you've set up a oneshot service that is designed to fail. This could be for testing purposes or to simulate a specific error condition. Here’s how you might create such a service:

Create a service file, for example, /etc/systemd/user/qnq-test-user-service-failure.service.

[Unit]
Description=Simulates a user service failure

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/nonexistent

[Install]
WantedBy=default.target

Enable the service for the current user:

systemctl --user enable qnq-test-user-service-failure

Reboot the system to observe the service's behavior on startup:
```
sudo reboot
```

After the reboot, you might expect the service to be in a failed state because /nonexistent is not a valid executable. However, when you check the status, you might see something like this:

○ qnq-test-user-service-failure.service - Simulates a user service failure
     Loaded: loaded (/etc/systemd/user/qnq-test-user-service-failure.service; enabled; preset: disabled)
    Drop-In: /usr/lib/systemd/user/service.d
             └─10-timeout-abort.conf
     Active: inactive (dead) since Fri 2025-10-17 01:08:08 CEST; 4min 3s ago
 Invocation: 528514dc419d4cfbbc6d42c328a45f51
    Process: 1411 ExecStart=/nonexistent (code=exited, status=203/EXEC)
   Main PID: 1411 (code=exited, status=203/EXEC)
   Mem peak: 1M
        CPU: 2ms

Oct 17 01:08:08 fedoratest systemd[1392]: Starting qnq-test-user-service-failure.service - Simulates a user service failure...
Oct 17 01:08:08 fedoratest (existent)[1411]: qnq-test-user-service-failure.service: Unable to locate executable '/nonexistent': No such file or directory
Oct 17 01:08:08 fedoratest (existent)[1411]: qnq-test-user-service-failure.service: Failed at step EXEC spawning /nonexistent: No such file or directory
Oct 17 01:08:08 fedoratest systemd[1392]: qnq-test-user-service-failure.service: Main process exited, code=exited, status=203/EXEC
Oct 17 01:08:08 fedoratest systemd[1392]: qnq-test-user-service-failure.service: Failed with result 'exit-code'.
Oct 17 01:08:08 fedoratest systemd[1392]: Failed to start qnq-test-user-service-failure.service - Simulates a user service failure.

Notice that the Active: line shows inactive (dead), which isn't quite right. Running systemctl --user is-failed confirms this discrepancy:

$ systemctl --user is-failed qnq-test-user-service-failure; echo $?
inactive
1

The command incorrectly reports inactive and returns an exit code of 1, which indicates a non-failed state. This is misleading.

The Temporary Fix

Interestingly, manually starting the service after this point corrects the reported state:

$ systemctl --user start qnq-test-user-service-failure
Job for qnq-test-user-service-failure.service failed because the control process exited with error code.
See "systemctl --user status qnq-test-user-service-failure.service" and "journalctl --user -xeu qnq-test-user-service-failure.service" for details.
$ systemctl --user is-failed qnq-test-user-service-failure; echo $?
failed
0

After manually starting the service, systemctl --user is-failed correctly reports failed with an exit code of 0. This workaround highlights an underlying issue in how systemd initially handles the state of these oneshot services.

Why Does This Happen?

To understand why this happens, let's break down the key components and behaviors of systemd.

Oneshot Services

Oneshot services in systemd are designed for tasks that execute once and then exit. They are commonly used for initialization scripts, scheduled tasks, or any operation that doesn't require a persistent background process. The Type=oneshot directive in the service file tells systemd to treat the service in this manner.

The RemainAfterExit=yes directive is crucial here. It instructs systemd to keep the service's status as active even after the main process has exited. This is useful for scenarios where you want to track the outcome of the service execution, such as whether it succeeded or failed.

The Role of `systemctl --user is-failed`

The systemctl --user is-failed command checks whether a service is in a failed state. It does this by examining the service's properties, including its active state and result. If a service has failed, it should report failed and return an exit code of 0. If it's not in a failed state, it should report inactive or another appropriate state and return a non-zero exit code.

The Discrepancy

The issue arises from a possible race condition or timing issue within systemd's user service management. When a oneshot service fails quickly (as in the case of a non-existent executable), systemd might not correctly register the failure state before the service transitions to an inactive state. This can lead to the incorrect reporting by systemctl --user is-failed.

Diagnosing the Problem

To effectively diagnose this issue, consider the following steps:

Check the Service Status:

Use systemctl --user status <service-name> to get a detailed view of the service's state. Look for clues in the logs and the active status line.
Examine the Journal:

The journalctl is invaluable for debugging systemd services. Use journalctl --user -xeu <service-name> to see detailed logs for the service.
Review the Service File:

Ensure that your service file (/etc/systemd/user/<service-name>.service) is correctly configured. Pay special attention to the Type, ExecStart, and RemainAfterExit directives.
Reproduce the Issue:

Try to reproduce the issue consistently. If it only happens sporadically, it might be harder to diagnose.

Potential Solutions and Workarounds

While a root cause analysis might require deeper investigation into systemd's internals, here are some potential solutions and workarounds:

1. Ensure Correct Service Configuration

Double-Check ExecStart: Make sure the executable path in ExecStart is correct. A common mistake is a typo or an incorrect path.
Use Absolute Paths: Whenever possible, use absolute paths for executables to avoid path-related issues.

2. Implement Retries

For services that might fail intermittently, consider adding retry logic. You can use the Restart and RestartSec directives in the service file to automatically restart the service after a failure.
```
[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/path/to/your/script
Restart=on-failure
RestartSec=5
```
This configuration tells systemd to restart the service if it fails, waiting 5 seconds before the next attempt.

3. Use `ExecStartPost` for State Management

The ExecStartPost directive allows you to run a command after the main service process has finished. You can use this to explicitly set the service's state based on the outcome of the execution.
```
[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/path/to/your/script
ExecStartPost=/path/to/a/script/that/checks/result
```
In the ExecStartPost script, you can check the exit code of the main process and use systemctl --user reset-failed <service-name> to clear the failed state if necessary.

4. Delay Service Start

In some cases, delaying the start of the service might help avoid race conditions. You can use the After directive to ensure that the service starts after certain dependencies are met.
```
[Unit]
Description=My Service
After=network.target

[Service]
Type=oneshot
ExecStart=/path/to/your/script
```
This ensures that the service starts after the network is up.

5. Manually Resetting the Failed State

As a workaround, you can manually reset the failed state using systemctl --user reset-failed <service-name>. This might be useful in automated scripts or troubleshooting sessions.

Real-World Examples and Use Cases

Let's explore some real-world examples where this issue might surface and how to address it.

Example 1: Intermittent Network Issues

Suppose you have a oneshot service that performs a network-related task, such as downloading a file or synchronizing data. If the network is temporarily unavailable, the service might fail. In this case, using Restart=on-failure and RestartSec can help ensure that the service retries until the network is available.

[Unit]
Description=Download a file
After=network.target

[Service]
Type=oneshot
ExecStart=/usr/bin/wget https://example.com/file.txt
Restart=on-failure
RestartSec=10

Example 2: Scheduled Tasks

For scheduled tasks that might fail due to various reasons (e.g., resource constraints, external dependencies), using ExecStartPost to check the outcome and manage the service state can be beneficial.

[Unit]
Description=Run a scheduled task

[Service]
Type=oneshot
ExecStart=/path/to/your/task
ExecStartPost=/path/to/check_task_result.sh
RemainAfterExit=yes

In check_task_result.sh, you can check the exit code of the task and take appropriate action:

#!/bin/bash

if [ $? -ne 0 ]; then
    echo "Task failed. Resetting failed state."
    systemctl --user reset-failed your-service.service
fi

Example 3: User Session Services

In user sessions, services might fail due to user-specific configurations or resource limits. Correctly handling the failed state is crucial for providing a smooth user experience. Using a combination of RemainAfterExit and manual state checks can help.

Best Practices for Systemd Service Management

To avoid issues like incorrect failure reporting, here are some best practices for managing systemd services:

Write Clear and Concise Service Files:
- Use descriptive comments to explain the purpose of each directive.
- Keep the service file as simple as possible.
Use Absolute Paths:
- Always use absolute paths for executables and scripts to avoid ambiguity.
Handle Dependencies:
- Use the After and Before directives to manage service dependencies.
Implement Proper Error Handling:
- Use ExecStartPost to check the outcome of the service and handle failures gracefully.
Monitor Service Status:
- Regularly check the status of your services using systemctl and journalctl.
Test Thoroughly:
- Test your services in a controlled environment before deploying them to production.

Conclusion

The issue of systemctl --user is-failed reporting the wrong state for failed oneshot services can be perplexing, but understanding the underlying mechanisms of systemd helps in diagnosing and resolving it. By ensuring correct service configurations, implementing retries, and managing service states explicitly, you can mitigate this problem and ensure your systemd services behave as expected.

Remember, debugging systemd services often involves a combination of careful configuration, log analysis, and a bit of experimentation. With the right approach, you can keep your systems running smoothly and reliably. Happy troubleshooting, guys! 💪