Modification to /run is not captured #429
Description
Because /run is mounted as tmpfs, unlike Docker.
$ docker build -t foo . && docker run -it --rm foo ls -l /run
Sending build context to Docker daemon 2.048kB
Step 1/2 : FROM busybox
---> 8c811b4aec35
Step 2/2 : RUN mkdir -p /run && echo hello > /run/hello
---> Running in 6a5b0410c0c8
Removing intermediate container 6a5b0410c0c8
---> 26c30d301753
Successfully built 26c30d301753
Successfully tagged foo:latest
total 4
-rw-r--r-- 1 root root 6 Jun 4 14:12 hello
$ sudo build-using-dockerfile -t foo . && docker run -it --rm foo ls -l /run
[+] Building 3.6s (5/5) FINISHED
=> local://context (.dockerignore) 0.0s
=> => transferring context: 02B 0.0s
=> local://dockerfile (Dockerfile) 0.1s
=> => transferring dockerfile: 101B 0.0s
=> docker-image://docker.io/library/busybox@sha256:141c253bc4c3fd0a201d32dc1f493bcf3fff003b6df416dea4f41046e0f37d47 0.0s
=> => resolve docker.io/library/busybox@sha256:141c253bc4c3fd0a201d32dc1f493bcf3fff003b6df416dea4f41046e0f37d47 0.0s
=> => sha256:141c253bc4c3fd0a201d32dc1f493bcf3fff003b6df416dea4f41046e0f37d47 2.70kB / 2.70kB 0.0s
=> => sha256:74f634b1bc1bd74535d5209589734efbd44a25f4e2dc96d78784576a3eb5b335 527B / 527B 0.0s
=> => sha256:07a152489297fc2bca20be96fab3527ceac5668328a30fd543a160cd689ee548 723.15kB / 723.15kB 0.0s
=> => sha256:8c811b4aec35f259572d0f79207bc0678df4c736eeec50bc9fec37ed936a472a 1.50kB / 1.50kB 0.0s
=> => unpacking docker.io/library/busybox@sha256:141c253bc4c3fd0a201d32dc1f493bcf3fff003b6df416dea4f41046e0f37d47 0.0s
=> /bin/sh -c mkdir -p /run && echo hello > /run/hello 0.2s
=> exporting to oci image format 0.4s
=> => exporting layers 0.3s
=> => exporting manifest sha256:83a9ac75cdfe48de0028a9016b1d72a00d340ccb60133b405111d0621766cfcc 0.0s
=> => exporting config sha256:9c539798303e23f5cf22e2c124fab9eea84883c365a67cd5bc8e1216c1e21902 0.0s
=> => sending tarball 0.0s
INFO[0003] Loading the image to Docker as "foo". This may take a while.
0c53f8a6b89d: Loading layer [==================================================>] 179B/179B
The image foo:latest already exists, renaming the old one with ID sha256:26c30d3017532dd1a6bd991e2d6856af2927f61f85454534d9f23e55345d6506 to empty string
Loaded image: foo:latest
INFO[0003] Done
total 0