systemd

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To make a service in Linux wait until another service is up and running, you can use a combination of shell scripting and system commands. Here’s a general approach using a bash script:

Method 1: Using a Bash Script

Create a script:
Create a script that checks if the second service is running and waits until it is.

#!/bin/bash

# Function to check if the service is running

is_service_running() {

    systemctl is-active --quiet your_service_2

}

# Wait until the second service is active

while ! is_service_running; do

    echo "Waiting for service 2 to start..."

    sleep 5  # Wait for 5 seconds before checking again

done

# Start your service 1

echo "Service 2 is up. Starting service 1..."

systemctl start your_service_1

Replace your_service_1 and your_service_2 with the actual service names.

Make the script executable:

chmod +x /path/to/your_script.sh

Run the script: You can run this script manually or set it to execute at startup.

Method 2: Using Systemd Service Dependencies

If you are using systemd, you can configure service dependencies directly in the service files:

Edit the service file for Service 1:

sudo systemctl edit your_service_1

Add the following lines:

[Unit]

Requires=your_service_2.service

After=your_service_2.service

Save and exit.

Important Notes:

The first method gives you more control and can be customized further.

The second method is cleaner and leverages systemd's built-in dependency management.