Using Docker Compose overrides

Sometimes, we want to run our applications in different environments that need specific configuration settings. Docker Compose provides a handy capability to address exactly this issue.

Let’s illustrate the with a specific sample:

1. Open a new browser window and navigate to the chapter’s folder (ch11):

   $ cd ~/The-Ultimate-Docker-Container-Book/ch11

2. Create a subfolder called step4 and navigate to it:

   $ mkdir step4 && cd step4

3. Copy the web and db folder and their contents from the step2 folder into the step4 folder:

   $ cp -r ../step2/web .$ cp -r ../step2/db .

4. We can define a base Docker Compose file and then define environment-specific overrides. Let’s assume we have a file called dockercompose.base.yml with the following content:

Figure 11.23 – Docker Compose file used as a base

This only defines the part that should be the same in all environments. All specific settings...