Docker fully qualified image names (#15689)

* Fully qualified docker image names for the main Dockerfile and Complement related.

* Fully qualified docker image names for Dockerfiles associated with building Debian release artifacts.

This one is harder and is separate from the other commit in case it wasn't correct or was unwanted. I decided to
do the expansion on the docker images in the Dockerfile itself, instead of the various source places that build
which distribution that is selected, as it would have been more invasive with the scripts breaking up the string
for tagging and such. This one is untested.

* Changelog

* Update docker/Dockerfile-workers

* Update docker/complement/Dockerfile

---------

Co-authored-by: reivilibre <olivier@librepush.net>

8 files changed, 15 insertions, 10 deletions

diff --git a/.github/workflows/release-artifacts.yml b/.github/workflows/release-artifacts.yml
index ebd7d298a9..0981200401 100644
--- a/.github/workflows/release-artifacts.yml
+++ b/.github/workflows/release-artifacts.yml
@@ -34,6 +34,7 @@ jobs:
       - id: set-distros
         run: |
           # if we're running from a tag, get the full list of distros; otherwise just use debian:sid
+          # NOTE: inside the actual Dockerfile-dhvirtualenv, the image name is expanded into its full image path
           dists='["debian:sid"]'
           if [[ $GITHUB_REF == refs/tags/* ]]; then
               dists=$(scripts-dev/build_debian_packages.py --show-dists-json)
diff --git a/changelog.d/15689.misc b/changelog.d/15689.misc
new file mode 100644
index 0000000000..4262cc9515
--- /dev/null
+++ b/changelog.d/15689.misc
@@ -0,0 +1 @@
+Add fully qualified docker image names to Dockerfiles.
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 6107dced43..12cff84131 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -27,7 +27,7 @@ ARG PYTHON_VERSION=3.11
 ###
 # We hardcode the use of Debian bullseye here because this could change upstream
 # and other Dockerfiles used for testing are expecting bullseye.
-FROM docker.io/python:${PYTHON_VERSION}-slim-bullseye as requirements
+FROM docker.io/library/python:${PYTHON_VERSION}-slim-bullseye as requirements
 
 # RUN --mount is specific to buildkit and is documented at
 # https://github.com/moby/buildkit/blob/master/frontend/dockerfile/docs/syntax.md#build-mounts-run---mount.
@@ -87,7 +87,7 @@ RUN if [ -z "$TEST_ONLY_IGNORE_POETRY_LOCKFILE" ]; then \
 ###
 ### Stage 1: builder
 ###
-FROM docker.io/python:${PYTHON_VERSION}-slim-bullseye as builder
+FROM docker.io/library/python:${PYTHON_VERSION}-slim-bullseye as builder
 
 # install the OS build deps
 RUN \
@@ -158,7 +158,7 @@ RUN --mount=type=cache,target=/synapse/target,sharing=locked \
 ### Stage 2: runtime
 ###
 
-FROM docker.io/python:${PYTHON_VERSION}-slim-bullseye
+FROM docker.io/library/python:${PYTHON_VERSION}-slim-bullseye
 
 LABEL org.opencontainers.image.url='https://matrix.org/docs/projects/server/synapse'
 LABEL org.opencontainers.image.documentation='https://github.com/matrix-org/synapse/blob/master/docker/README.md'
diff --git a/docker/Dockerfile-dhvirtualenv b/docker/Dockerfile-dhvirtualenv
index 2013732422..861129ebc2 100644
--- a/docker/Dockerfile-dhvirtualenv
+++ b/docker/Dockerfile-dhvirtualenv
@@ -24,7 +24,7 @@ ARG distro=""
 # https://launchpad.net/~jyrki-pulliainen/+archive/ubuntu/dh-virtualenv, but
 # it's not obviously easier to use that than to build our own.)
 
-FROM ${distro} as builder
+FROM docker.io/library/${distro} as builder
 
 RUN apt-get update -qq -o Acquire::Languages=none
 RUN env DEBIAN_FRONTEND=noninteractive apt-get install \
@@ -55,7 +55,7 @@ RUN cd /dh-virtualenv && DEB_BUILD_OPTIONS=nodoc dpkg-buildpackage -us -uc -b
 ###
 ### Stage 1
 ###
-FROM ${distro}
+FROM docker.io/library/${distro}
 
 # Get the distro we want to pull from as a dynamic build variable
 # (We need to define it in each build stage)
diff --git a/docker/Dockerfile-workers b/docker/Dockerfile-workers
index faf7f2cef8..adb9a725e3 100644
--- a/docker/Dockerfile-workers
+++ b/docker/Dockerfile-workers
@@ -7,7 +7,7 @@ ARG FROM=matrixdotorg/synapse:$SYNAPSE_VERSION
 # target image. For repeated rebuilds, this is much faster than apt installing
 # each time.
 
-FROM debian:bullseye-slim AS deps_base
+FROM docker.io/library/debian:bullseye-slim AS deps_base
     RUN \
        --mount=type=cache,target=/var/cache/apt,sharing=locked \
        --mount=type=cache,target=/var/lib/apt,sharing=locked \
@@ -21,7 +21,7 @@ FROM debian:bullseye-slim AS deps_base
 # which makes it much easier to copy (but we need to make sure we use an image
 # based on the same debian version as the synapse image, to make sure we get
 # the expected version of libc.
-FROM redis:6-bullseye AS redis_base
+FROM docker.io/library/redis:6-bullseye AS redis_base
 
 # now build the final image, based on the the regular Synapse docker image
 FROM $FROM
diff --git a/docker/complement/Dockerfile b/docker/complement/Dockerfile
index be1aa1c55e..5103068a49 100644
--- a/docker/complement/Dockerfile
+++ b/docker/complement/Dockerfile
@@ -7,6 +7,7 @@
 # https://github.com/matrix-org/synapse/blob/develop/docker/README-testing.md#testing-with-postgresql-and-single-or-multi-process-synapse
 
 ARG SYNAPSE_VERSION=latest
+# This is an intermediate image, to be built locally (not pulled from a registry).
 ARG FROM=matrixdotorg/synapse-workers:$SYNAPSE_VERSION
 
 FROM $FROM
@@ -19,8 +20,8 @@ FROM $FROM
     # the same debian version as Synapse's docker image (so the versions of the
     # shared libraries match).
     RUN adduser --system --uid 999 postgres --home /var/lib/postgresql
-    COPY --from=postgres:13-bullseye /usr/lib/postgresql /usr/lib/postgresql
-    COPY --from=postgres:13-bullseye /usr/share/postgresql /usr/share/postgresql
+    COPY --from=docker.io/library/postgres:13-bullseye /usr/lib/postgresql /usr/lib/postgresql
+    COPY --from=docker.io/library/postgres:13-bullseye /usr/share/postgresql /usr/share/postgresql
     RUN mkdir /var/run/postgresql && chown postgres /var/run/postgresql
     ENV PATH="${PATH}:/usr/lib/postgresql/13/bin"
     ENV PGDATA=/var/lib/postgresql/data
diff --git a/docker/editable.Dockerfile b/docker/editable.Dockerfile
index 0e8cf2e712..c53ce1c718 100644
--- a/docker/editable.Dockerfile
+++ b/docker/editable.Dockerfile
@@ -10,7 +10,7 @@ ARG PYTHON_VERSION=3.9
 ###
 # We hardcode the use of Debian bullseye here because this could change upstream
 # and other Dockerfiles used for testing are expecting bullseye.
-FROM docker.io/python:${PYTHON_VERSION}-slim-bullseye
+FROM docker.io/library/python:${PYTHON_VERSION}-slim-bullseye
 
 # Install Rust and other dependencies (stolen from normal Dockerfile)
 # install the OS build deps
diff --git a/scripts-dev/build_debian_packages.py b/scripts-dev/build_debian_packages.py
index ede7665011..4c9f134ddd 100755
--- a/scripts-dev/build_debian_packages.py
+++ b/scripts-dev/build_debian_packages.py
@@ -20,6 +20,8 @@ from concurrent.futures import ThreadPoolExecutor
 from types import FrameType
 from typing import Collection, Optional, Sequence, Set
 
+# These are expanded inside the dockerfile to be a fully qualified image name.
+# e.g. docker.io/library/debian:bullseye
 DISTS = (
     "debian:buster",  # oldstable: EOL 2022-08
     "debian:bullseye",