Backup web application with Docker

Question

(Excuse me for my bad english)

On the Linux server installed Apache, PHP, MySQL, GitLab, Shiny. This server developers use as a sandbox by connecting via ssh. Current backup implemented on bash script and packed in tgz.

Problems:

1. The need to control the relevance of the files in backup;
2. The deployment of application from the backup is not fast (more than an hour already critical);
3. As a consequence of the preceding paragraph, poor portability.

I want to pack everything in Docker container, and install in the official base image of Ubuntu ssh, LAMP, etc. Backup do with docker commit and docker push on schedule. In version specify the current date and time. Confuses that can be pitfalls of docker usage, which are difficult to predict. (For example, recently I deployed WordPress in Docker, it turned out that "WordPress saves the last IP as its 'Home' and 'Site' URL.". As a result, on another machine with a different ip WordPress tried to load the css/js from old host ip).

What are the advantages and disadvantages of using Docker as a backup system? What are the alternative solutions for backup?