diff --git a/docker/Dockerfile-dhvirtualenv b/docker/Dockerfile-dhvirtualenv
index 1dd88140c7..fbc1d2346f 100644
--- a/docker/Dockerfile-dhvirtualenv
+++ b/docker/Dockerfile-dhvirtualenv
@@ -16,7 +16,7 @@ ARG distro=""
### Stage 0: build a dh-virtualenv
###
-# This is only really needed on bionic and focal, since other distributions we
+# This is only really needed on focal, since other distributions we
# care about have a recent version of dh-virtualenv by default. Unfortunately,
# it looks like focal is going to be with us for a while.
#
@@ -36,9 +36,8 @@ RUN env DEBIAN_FRONTEND=noninteractive apt-get install \
wget
# fetch and unpack the package
-# TODO: Upgrade to 1.2.2 once bionic is dropped (1.2.2 requires debhelper 12; bionic has only 11)
RUN mkdir /dh-virtualenv
-RUN wget -q -O /dh-virtualenv.tar.gz https://github.com/spotify/dh-virtualenv/archive/ac6e1b1.tar.gz
+RUN wget -q -O /dh-virtualenv.tar.gz https://github.com/spotify/dh-virtualenv/archive/refs/tags/1.2.2.tar.gz
RUN tar -xv --strip-components=1 -C /dh-virtualenv -f /dh-virtualenv.tar.gz
# install its build deps. We do another apt-cache-update here, because we might
@@ -86,12 +85,12 @@ RUN apt-get update -qq -o Acquire::Languages=none \
libpq-dev \
xmlsec1
-COPY --from=builder /dh-virtualenv_1.2~dev-1_all.deb /
+COPY --from=builder /dh-virtualenv_1.2.2-1_all.deb /
# install dhvirtualenv. Update the apt cache again first, in case we got a
# cached cache from docker the first time.
RUN apt-get update -qq -o Acquire::Languages=none \
- && apt-get install -yq /dh-virtualenv_1.2~dev-1_all.deb
+ && apt-get install -yq /dh-virtualenv_1.2.2-1_all.deb
WORKDIR /synapse/source
ENTRYPOINT ["bash","/synapse/source/docker/build_debian.sh"]
diff --git a/docker/README.md b/docker/README.md
index 4349e71f87..67c3bc65f0 100644
--- a/docker/README.md
+++ b/docker/README.md
@@ -68,6 +68,10 @@ The following environment variables are supported in `generate` mode:
directories. If unset, and no user is set via `docker run --user`, defaults
to `991`, `991`.
+## Postgres
+
+By default the config will use SQLite. See the [docs on using Postgres](https://github.com/matrix-org/synapse/blob/develop/docs/postgres.md) for more info on how to use Postgres. Until this section is improved [this issue](https://github.com/matrix-org/synapse/issues/8304) may provide useful information.
+
## Running synapse
Once you have a valid configuration file, you can start synapse as follows:
|
