Minor optimization to `pip install` in gmxapi CI build.

Change-Id: I247ca2c253a73b30cd21f36914bcf7c0ecbd7aa2

diff --git a/python_packaging/docker/ci.dockerfile b/python_packaging/docker/ci.dockerfile
index ffd269826eda479b04f700b7156d3fe3b103743d..6fe196804ef02a7f9c52ec66f30ae31d80caee44 100644 (file)
--- a/python_packaging/docker/ci.dockerfile
+++ b/python_packaging/docker/ci.dockerfile
@@ -63,10 +63,13 @@ COPY --from=gromacs /usr/local/gromacs /usr/local/gromacs
 ADD --chown=testing:testing src /home/testing/gmxapi/src
 ADD --chown=testing:testing src/gmxapi /home/testing/gmxapi/src/gmxapi
 
+# We use "--no-cache-dir" to reduce Docker image size. The other pip flags are
+# to eliminate network access and speed up the build, since we already know we
+# have installed the dependencies.
 RUN . $VENV/bin/activate && \
     . /usr/local/gromacs/bin/GMXRC && \
     (cd $HOME/gmxapi/src && \
-     pip install --no-cache-dir . \
+     pip install --no-cache-dir --no-deps --no-index --no-build-isolation . \
     )
 
 ADD --chown=testing:testing src/test /home/testing/gmxapi/test