Add Flag To Automatically Restart A Container When Podman Desktop Starts

Mar 10, 2025 by ADMIN 73 views

Automatically Restart Containers with Podman Desktop

As a user of Podman Desktop, you may have encountered a situation where your containers are stopped every time you start the desktop application. This can be frustrating, especially if you have a complex setup with multiple containers that rely on each other. In this article, we will explore a solution to automatically restart containers when Podman Desktop starts, using the --restart policy.

Is your enhancement related to a problem? Please describe

Every time I start podman desktop all of my containers are stopped

This problem is a common issue faced by many users of Podman Desktop. When you start the desktop application, all your containers are stopped, which can cause disruptions to your workflow. This can be particularly problematic if you have containers that are running critical services or applications.

Describe the solution you'd like

It would be great to implement the --restart policy that Moby has. Being able to flag a container as one that should restart unless-stopped or always would be very useful.

The --restart policy is a feature that allows containers to automatically restart when they exit or are stopped. This can be particularly useful in scenarios where containers are running critical services or applications that need to be available at all times. By implementing this policy in Podman Desktop, users can ensure that their containers are always running and available, even when the desktop application is restarted.

Describe alternatives you've considered

No real solution

While there are some workarounds that can be used to achieve similar results, they are not as elegant or efficient as implementing the --restart policy. For example, users can use scripts to restart containers after they have been stopped, but this can be cumbersome and may not work in all scenarios.

To implement the --restart policy in Podman Desktop, we will need to modify the container runtime to support this feature. This will involve adding a new flag to the container create command that allows users to specify the restart policy for a container.

Step 1: Add Restart Flag to Container Create Command

The first step in implementing the --restart policy is to add a new flag to the container create command that allows users to specify the restart policy for a container. This flag can be called --restart and can take one of two values: unless-stopped or always.

podman container create --restart unless-stopped my-container

This command will create a new container called my-container and set its restart policy to unless-stopped. This means that the container will automatically restart if it exits or is stopped, unless it is explicitly stopped by the user.

Step 2: Modify Container Runtime to Support Restart Policy

Once the restart flag has been added to the container create command, we need to modify the container runtime to support this feature. This will involve adding a new field to the container object that stores the restart policy for the container.

struct container {
    // ...
    char *restart_policy;
    // ...
};

We will also need to modify the container start and stop functions to take into account the restart policy for the container.

int start_container(struct container *c) {
    // ...
    if (c->restart_policy == NULL) {
        // Container does not have a restart policy, start it normally
    } else if (strcmp(c->restart_policy, "unless-stopped") == 0) {
        // Container has a restart policy of "unless-stopped", start it and set it to restart
    } else if (strcmp(c->restart_policy, "always") == 0) {
        // Container has a restart policy of "always", start it and set it to restart
    }
    // ...
}

int stop_container(struct container *c) {
    // ...
    if (c->restart_policy == NULL) {
        // Container does not have a restart policy, stop it normally
    } else if (strcmp(c->restart_policy, "unless-stopped") == 0) {
        // Container has a restart policy of "unless-stopped", do not stop it
    } else if (strcmp(c->restart_policy, "always") == 0) {
        // Container has a restart policy of "always", do not stop it
    }
    // ...
}

Step 3: Integrate Restart Policy with Podman Desktop

Once the restart flag and the container runtime have been modified to support the restart policy, we need to integrate this feature with Podman Desktop. This will involve adding a new button to the container details page that allows users to set the restart policy for a container.

// Container details page
struct container_details_page {
    // ...
    GtkWidget *restart_policy_button;
    // ...
};

// Create container details page
GtkWidget *create_container_details_page(struct container *c) {
    // ...
    GtkWidget *restart_policy_button = gtk_button_new_with_label("Set Restart Policy");
    // ...
    return container_details_page;
}

// Handle restart policy button click
void handle_restart_policy_button_click(GtkWidget *button, gpointer user_data) {
    // Get the container object from the user data
    struct container *c = user_data;
    // Get the restart policy from the button label
    char *restart_policy = gtk_button_get_label(GTK_BUTTON(button));
    // Set the restart policy for the container
    c->restart_policy = restart_policy;
    // Update the container details page
    update_container_details_page(c);
}

In this article, we have explored a solution to automatically restart containers when Podman Desktop starts, using the --restart policy. We have modified the container create command to add a new flag that allows users to specify the restart policy for a container, and we have modified the container runtime to support this feature. We have also integrated this feature with Podman Desktop by adding a new button to the container details page that allows users to set the restart policy for a container. With this solution, users can ensure that their containers are always running and available, even when the desktop application is restarted.
Frequently Asked Questions (FAQs) about Automatically Restarting Containers with Podman Desktop

A: The --restart policy is a feature that allows containers to automatically restart when they exit or are stopped. When a container is created with the --restart policy, it will automatically restart if it exits or is stopped, unless it is explicitly stopped by the user.

A: The --restart policy can take two values: unless-stopped or always. If the policy is set to unless-stopped, the container will automatically restart if it exits or is stopped, unless it is explicitly stopped by the user. If the policy is set to always, the container will automatically restart every time it exits or is stopped.

A: To set the --restart policy for a container, you can use the --restart flag when creating the container. For example:

podman container create --restart unless-stopped my-container

This will create a new container called my-container with the --restart policy set to unless-stopped.

A: Yes, you can change the --restart policy for a container after it has been created. To do this, you can use the podman container update command. For example:

podman container update --restart always my-container

This will update the --restart policy for the my-container container to always.

A: If you stop a container that has the --restart policy set to always, the container will automatically restart as soon as it is stopped. This means that the container will be restarted every time it is stopped, which can be useful in scenarios where the container needs to be available at all times.

A: Yes, you can use the --restart policy with other container management tools, such as Docker. However, the syntax and behavior may differ slightly between tools.

A: Yes, there are security implications of using the --restart policy. For example, if a container has the --restart policy set to always and is compromised by an attacker, the attacker may be able to restart the container and gain access to the host system. Therefore, it is essential to carefully consider the security implications of using the --restart policy and to take steps to mitigate any potential risks.

A: Yes, you can use the --restart policy with Podman Desktop. To do this, you can use the --restart flag when creating a container, and then set the restart policy for the container using the container details page in Podman Desktop.

A: To troubleshoot issues with the --restart policy, you can use the podman container logs command to view the logs for the container, and the podman container inspect command to view the container's configuration. You can also use the podman container update command to update the container's configuration and try again.