Removing Dependent Child Images of a Docker Container

As much as I love using Docker, one of the frustrations I have is when I try to remove an an image which other images are based on, only to get this error:

$ docker rmi b171179240df
Error response from daemon: conflict: unable to delete b171179240df (cannot be forced) - image has dependent child images
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I did some searches on Google, and most of the advice centered around the heavy-handed approach of removing¬†all¬†Docker images and basically starting over with a clean slate. That approach didn’t sit well with me because it doesn’t strike me as all that efficient, and also causes me to have to spend more time waiting for unrelated containers to rebuild.

That prompted me to write a script which, when provided with the ID of a container to remove, will recurse through all child containers and delete them first.

Quick and Dirty Usage

bash <(curl -s IMAGE_ID

That will delete the image IMAGE_ID, and all child images.

No muss, no fuss, no awkward explanations to senior engineers.

When run successfully, the output will look something like this:

The source and testing scripts can be found over on GitHub at

Does this script save you some time? Let me know in the comments!

How to Undelete Files in Amazon S3

While S3 is a great storage platform, what happens if you accidentally delete some important files? Well, S3 has a mechanism to recover deleted files, and I’d like to go into that in this post.

First, make sure you have versioning enabled on your bucket. This can be done via the API, or via the UI in the “properties” tab for your bucket. Versioning saves every change to a file (including deletions) as a separate version of said object, with the most recent version taking precedence. In fact, a deletion is also a version! It is a zero-byte version which has a “DELETE” flag set. And the essence of recovering undeleted files simply involves removing the latest version with the “DELETE” flag.

This is what that would look like in the UI:

To undelete these files, we’ll use a script I created called, which can be found over on GitHub:

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