Add guidelines for running Saraswati on Docker

.dockerignore

@@ -0,0 +1,8 @@
+*
+
+!saraswati
+!setup.py
+!LICENSE
+!README.rst
+!CHANGES.rst
+!MANIFEST.in

CHANGES.rst

@@ -6,6 +6,8 @@ Saraswati changelog
 in progress
 ===========
 
+- Add guidelines for running Saraswati on Docker
+
 
 2021-06-21 0.3.0
 ================

doc/setup-sandbox.rst

@@ -16,3 +16,16 @@ Clone source repository
 
     # Invoke test suite
     make test
+
+
+Using Docker for development
+============================
+
+This will give you a Linux environment, even on non-Linux workstations.
+
+::
+
+    docker build --file=dockerfiles/develop.Dockerfile --tag=saraswati-develop .
+    docker run -it --rm --volume=$PWD:/src saraswati-develop bash
+    pip3 install --editable=/src
+    saraswati record --channel="testdrive source=audiotestsrc wave=3 freq=200"

dockerfiles/develop.Dockerfile

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+# Docker build file for Saraswati development.
+#
+# Invoke like:
+#
+#   docker build --file=dockerfiles/develop.Dockerfile --tag=saraswati-develop .
+#
+FROM amd64/debian:bullseye-slim
+
+RUN apt-get update && \
+    apt-get install --yes \
+        libgstreamer1.0 gstreamer1.0-tools gstreamer1.0-alsa gstreamer1.0-plugins-base gstreamer1.0-plugins-good \
+        python3 python3-pip python3-gst-1.0 python3-gi python3-tz \
+        alsa-utils mkvtoolnix flac wavpack

dockerfiles/runtime.Dockerfile

@@ -0,0 +1,30 @@
+# Docker build file for Saraswati runtime.
+#
+# Invoke like:
+#
+#   docker build --file=dockerfiles/runtime.Dockerfile --tag=saraswati-runtime .
+#
+FROM amd64/debian:bullseye-slim
+
+RUN apt-get update && \
+    apt-get install --yes \
+        libgstreamer1.0 gstreamer1.0-tools gstreamer1.0-alsa gstreamer1.0-plugins-base gstreamer1.0-plugins-good \
+        python3 python3-pip python3-gst-1.0 python3-gi python3-tz \
+        alsa-utils mkvtoolnix flac wavpack
+
+# Create /etc/saraswati
+RUN mkdir -p /etc/saraswati
+
+# Add user "saraswati"
+RUN groupadd -r saraswati && useradd -r -g saraswati saraswati
+RUN chown -R saraswati:saraswati /etc/saraswati
+
+# Install saraswati
+COPY . /src
+RUN pip install /src
+
+# Make process run as "saraswati" user
+USER saraswati
+
+# Invoke program
+CMD saraswati