bind mount /prop-test/src at /prop-test/vol/mp

Dockerfile

@@ -0,0 +1,8 @@
+FROM alpine:3.9
+
+CMD set -x \
+    && mkdir -p /prop-test/src /prop-test/vol/mp \
+    && mount --bind /prop-test/src /prop-test/vol/mp \
+    && date -Is > /prop-test/src/mount-timestamp \
+    && grep /prop-test /proc/self/mountinfo | tee /prop-test/src/mountinfo-container \
+    && sleep 21m

README.md

@@ -0,0 +1,12 @@
+Test propagation of bind mount.
+
+```sh
+docker run --rm --init \
+    --cap-add SYS_ADMIN --security-opt apparmor:unconfined \
+    -v /tmp/prop-test-host:/prop-test/vol:rshared \
+    --name mount-propagation-test fphammerle/mount-propagation-test
+cat /tmp/prop-test-host/mp/mountinfo-container
+```
+
+You may need to disable user namespace remapping `--userns host`
+due to https://github.com/moby/moby/issues/36472 .