Add scripts to verify compatibility with multiple Python versions, using Docker

pyproject.toml

@@ -18,6 +18,8 @@ description-file = "README.md"
 #        `typing.NoReturn` function signature support. (Also, many other `typing` module
 #        items were only introduced post-release in 3.6 and version restrictions on these
 #	     versions ensure that those are all available as well.)
+#
+#        Maintain this concurrently with verify.sh
 requires-python = ">=3.6.2,!=3.7.0,!=3.7.1"
 requires = [
 	"multiaddr (>=0.0.7)",

tools/verify/Dockerfile

@@ -0,0 +1,15 @@
+ARG PYTHON_VERSION
+
+FROM python:${PYTHON_VERSION}
+
+RUN pip install --upgrade pip
+RUN pip install tox
+
+# Mount the source code here, instead of to /usr/src/app.
+# Otherwise, tox will fail due to folder being read-only.
+# Mount only the source code; avoid mounting working folders.
+
+RUN mkdir /source
+ADD entrypoint.sh /
+
+ENTRYPOINT ["/entrypoint.sh"]

tools/verify/entrypoint.sh

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+cp -r /source/* /usr/src/app/
+
+exec $@
+

tools/verify/validate.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+
+set -e
+
+python_version=$1
+script_path=$(dirname $0)
+source=$(realpath "$script_path/../..")
+tag=py-ipfs-http-client-verify:$python_version
+
+pushd "$script_path"
+
+echo "Building validator for Python $python_version..."
+
+docker build --build-arg PYTHON_VERSION="$python_version" -t "$tag" .
+
+echo "Validating version $python_version"
+
+docker run \
+		-it \
+		-v "$source/docs":/source/docs:ro \
+		-v "$source/ipfshttpclient":/source/ipfshttpclient:ro \
+		-v "$source/test":/source/test:ro \
+		-v "$source/pyproject.toml":/source/pyproject.toml:ro \
+		-v "$source/README.md":/source/README.md:ro \
+		-v "$source/tox.ini":/source/tox.ini:ro \
+		-w /usr/src/app \
+		"$tag" \
+		tox -e styleck -e typeck
+
+popd
+

verify.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+set -e
+
+function validate() {
+	./tools/verify/validate.sh "$1"
+}
+
+if [ -z "$1" ]; then
+    echo "Validating minimum point release of each supported minor version..."
+
+    # Maintain this concurrently with [tool.flit.metadata].requires-python in pyproject.toml.
+    validate 3.6.2
+    validate 3.7.2
+    validate 3.8.0
+else
+    echo "Validating only $1..."
+    validate "$1"
+fi