If you are using Docker with Grafana Loki to visualize container log files, then you need to migrate from Promtail (default agent for Loki) to Alloy as Promtail is now End-of-Life (EOL).
Source of Announcement: Official Promtail Page
It means that:
- No releases of any security patches
- No Bug fixes or new improvements
The only way to move forward is to replace Promtail with Grafana Alloy 
I have created this video tutorial that explains very detailed step-by-step instructions on how to migrate your existing Promtail configuration files (for your Grafana Loki deployments) to Grafana Alloy 
in Docker environments and be able to keep using Loki without re-creating your dashboards or queries.
This tutorial is also for those users who are new to Grafana Alloy and want to get started with Docker Compose deployments with minimal effort.
Link to the article:
Here is the link to the complete article.
Link to the video:
Docker Tutorial: Getting started with Grafana Loki and Alloy | Complete Promtail Migration Guide
All the important links are available in the video description.
The video contains the following sections:
-
Starting with fundamentals for new users
-
Why Promtail is going EOL
-
Intro. to Grafana Alloy
(advantages, features) -
Demo Docker Compose Setup
-
Migration Setup for your Loki
-
Understanding Configuration
-
Advanced Debugging/Troubleshooting
-
Bonus Exercise
Please share, if you have any questions. Hope you will find this helpful 