Include Dockerfile in image

Addresses #55

Author: pont-us

docs/running-eoaps.md

@@ -5,13 +5,17 @@ also ways to run CWL files and complete Application Packages locally.
 
 ## Understanding and debugging xcengine container images
 
+### The base image
+
 When generating a container image, xcengine uses a
 [micromamba](https://mamba.readthedocs.io/en/latest/user_guide/micromamba.html)
 image as a base. If you need to investigate or
 debug an xcengine image, or if you're just curious about its structure, you may
 find the [micromamba-docker
 documentation](https://micromamba-docker.readthedocs.io/) useful.
 
+### Entry points
+
 xcengine sets a custom entry point to run its own runner script, so any commands
 provided when running a container from an xcengine image with `docker run`
 will be applied as arguments to the xcengine runner. For instance, for an
@@ -33,6 +37,15 @@ as well, like this:
 This resets the entry point to the usual micromamba-docker entry point, which
 sets up the Python environment, then runs bash within that environment.
 
+### The Dockerfile and environment file
+
+To aid reproducibility, the Dockerfile and environment file used to set up the
+container image are both included in the image itself, in the `/tmp`
+directory. The rest of the code and configuration for the image is in the
+`/home/mambauser` directory. In combination with the publicly available
+micromamba base image, each xcengine image thus contains the resources
+necessary to reproduce its own build process.
+
 ## Running with cwltool
 
 [cwltool](https://www.commonwl.org/user_guide/introduction/quick-start.html)

xcengine/core.py

@@ -302,6 +302,7 @@ def _build_image(self) -> docker.models.images.Image:
         dockerfile = textwrap.dedent(
             """
         FROM mambaorg/micromamba:1.5.10-noble-cuda-12.6.0
+        COPY Dockerfile Dockerfile
         COPY environment.yml environment.yml
         RUN micromamba install -y -n base -f environment.yml && \
         micromamba clean --all --yes