diff --git a/discogs_alert/util/currency.py b/discogs_alert/util/currency.py
index 81720f8..ea79bfc 100644
--- a/discogs_alert/util/currency.py
+++ b/discogs_alert/util/currency.py
@@ -12,7 +12,9 @@
 CurrencyRates = Dict[str, float]
 
 # Directory in which to store weekly CurrencyRates JSON caches
-CACHE_DIR = pathlib.Path(__file__).parent.parent.parent.resolve() / ".currency_cache"
+CACHE_DIR = os.getenv(
+    "DA_CURRENCY_CACHE_DIR", pathlib.Path(__file__).parent.parent.parent.resolve() / ".currency_cache"
+)
 
 
 class InvalidCurrencyException(Exception):
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 6b59068..de96105 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -18,18 +18,18 @@ RUN python -m venv /venv
 RUN . /venv/bin/activate
 
 # install Poetry (respects $POETRY_VERSION & $POETRY_HOME)
-ENV POETRY_VERSION=1.3.2
+ENV POETRY_VERSION=1.8.0
 RUN pip install "poetry==$POETRY_VERSION"
 
+# install chromium binary and matching chromedriver binary (+ gcc for installing e.g. psutil)
+RUN apt-get update && apt-get install -y --no-install-recommends chromium-driver gcc python3-dev
+
 # install dependences & create build version of package
 COPY pyproject.toml poetry.lock ./
 RUN poetry install --no-dev --no-root
 COPY . .
 RUN poetry build
 
-# install chromium binary and matching chromedriver binary
-RUN apt-get update && apt-get install -y --no-install-recommends chromium-driver
-
 
 # create lightweight 'final' stage with which to run discogs alert
 FROM python-base as final
@@ -37,10 +37,22 @@ FROM python-base as final
 # copy everything we need & install `discogs_alert` from whl
 COPY --from=builder /venv /venv
 COPY --from=builder /dist .
-COPY --from=builder /usr/bin/chromium /usr/bin/chromium
-COPY --from=builder /usr/bin/chromedriver /usr/bin/chromedriver
+
+# install chromium-driver, gcc, python3-dev (the latter two so that psutil can be installed)
+# ideally we'd just copy the builds over (that are already installed above), but that doesn't seem to work ...
+# COPY --from=builder /usr/bin/chromium /usr/bin/chromium
+# COPY --from=builder /usr/bin/chromedriver /usr/bin/chromedriver
+# COPY --from=builder /usr/bin/gcc /usr/bin/gcc
+# COPY --from=builder /usr/bin/python3-config /usr/bin/python3-config
+RUN apt-get update && apt-get install -y --no-install-recommends chromium-driver gcc python3-dev \
+    && apt-get clean && rm -rf /var/lib/apt/lists/*
+
 RUN . /venv/bin/activate && pip install *.whl
 
+# Create a directory in which to cache current conversion dicts
+ENV DA_CURRENCY_CACHE_DIR=/.currency_cache
+RUN mkdir $DA_CURRENCY_CACHE_DIR
+
 # run entrypoint
 COPY ./docker/docker-entrypoint.sh ./
-CMD ["./docker-entrypoint.sh"]
+ENTRYPOINT ["./docker-entrypoint.sh"]
diff --git a/docker/docker-entrypoint.sh b/docker/docker-entrypoint.sh
index 5f484a0..07505d8 100755
--- a/docker/docker-entrypoint.sh
+++ b/docker/docker-entrypoint.sh
@@ -1,7 +1,6 @@
 #!/bin/sh
 
 set -e
-
-. /home/discogs_alert/venv/bin/activate
-
-exec python -m discogs_alert
+. /venv/bin/activate
+echo Your container args are "$@"
+python -m discogs_alert "$@"