Project idea: a Google for docker images.
Search for files by hash within all public docker images.
Find images that contain a certain piece of code.
Reverse engineering Dockerfiles for those that were built without.
Search for files by hash within all public docker images.
Find images that contain a certain piece of code.
Reverse engineering Dockerfiles for those that were built without.
Every layer understands the command it was run in the Dockerfile to create itself. Just look at `docker history` and have a look at the "CREATED BY" field for human-readable output of the layer metadata, or depending on your graph driver have a look in /var/lib/docker/image/overlay2/imagedb/content/sha256. From there you can reverse-engineer a Dockerfile.
For layers that were not built using `docker build` (e.g. `docker commit`, OCI-compatible image builders), re-creating the exact command that generated that layer is much harder to do. The only information most tools will give you might just be the diff itself.
New project idea ... Crawl a large set of popular docker images lacking Dockerfiles and attempt to recreate the dockerfile with this technique.
How reliable is this? Can it be modified after creation by a malicious party?
That is, if I get a wild docker image, can I trust the results of `docker history`?
Docker the company could, I imagine, add deep search and browsing as enhancements to their existing Docker Hub.