Wrong tmpfs created for container

[linggao]

Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind bug

Description
Using REST API to create and start a container, specifying

  "HostConfig": { 
        "Tmpfs": {"/app": "rw"}
  }

But a "/app=rw" tmpfs instead of "/app" created in container.
Steps to reproduce the issue:

1. Run this script

#!/bin/bash

#clean up
echo -e "cleaning up..."
podman rm -f test

# create container
echo -e "\ncreating container test..."

read -d '' sdef <<EOF
{
  "Image": "alpine",
  "Cmd": [
      "sleep", "1000"
  ],
  "HostConfig": {
    "Tmpfs": {"/app": "rw"}
  }
}
EOF
echo "$sdef" | curl -sSLw "%{http_code}" -X POST -H "Content-Type: application/json" --unix-socket /var/run/podman/podman.sock --data @-  http://localhost/containers/create?name=test

echo -e "\n\n start container test"
curl -sSLw "%{http_code}" -X POST -H "Content-Type: application/json" --unix-socket /var/run/podman/podman.sock  http://localhost/containers/test/start

Describe the results you received:

$ docker exec -it test df
Filesystem           1K-blocks      Used Available Use% Mounted on
overlay              102174552   5235468  91732464   5% /
tmpfs                    65536         0     65536   0% /dev
tmpfs                  4073472         0   4073472   0% **/app=rw**
tmpfs                  4073472    392480   3680992  10% /run/secrets

Describe the results you expected:
"/app" tmpfs should be created.

Additional information you deem important (e.g. issue happens only occasionally):

Output of podman version:

Version:      3.1.0-dev
API Version:  3.0.0
Go Version:   go1.14.12
Git Commit:   1702cbc6917f431bcc65d6c5bdc6fcf99231977a-dirty
Built:        Wed Feb 24 09:13:30 2021
OS/Arch:      linux/amd64

Output of podman info --debug:

host:
  arch: amd64
  buildahVersion: 1.19.6
  cgroupManager: systemd
  cgroupVersion: v1
  conmon:
    package: Unknown
    path: /usr/local/libexec/podman/conmon
    version: 'conmon version 2.0.27-dev, commit: 7310bf13319ee8ed50799b202509bedc27b36cf8'
  cpus: 2
  distribution:
    distribution: '"rhel"'
    version: "8.3"
  eventLogger: file
  hostname: lingvs4.dev.edge-fabric.com
  idMappings:
    gidmap: null
    uidmap: null
  kernel: 4.18.0-240.15.1.el8_3.x86_64
  linkmode: dynamic
  memFree: 3188211712
  memTotal: 8342470656
  ociRuntime:
    name: runc
    package: Unknown
    path: /usr/bin/runc
    version: |-
      runc version 1.0.0-rc93+dev
      commit: f245a1d1edbf545549e5a16106cf1aec356a3c7d
      spec: 1.0.2-dev
      go: go1.14.12
      libseccomp: 2.4.3
  os: linux
  remoteSocket:
    exists: true
    path: /run/podman/podman.sock
  security:
    apparmorEnabled: false
    capabilities: CAP_AUDIT_WRITE,CAP_CHOWN,CAP_DAC_OVERRIDE,CAP_FOWNER,CAP_FSETID,CAP_KILL,CAP_MKNOD,CAP_NET_BIND_SERVICE,CAP_NET_RAW,CAP_SETFCAP,CAP_SETGID,CAP_SETPCAP,CAP_SETUID,CAP_SYS_CHROOT
    rootless: false
    seccompEnabled: true
    selinuxEnabled: true
  slirp4netns:
    executable: ""
    package: ""
    version: ""
  swapFree: 2146758656
  swapTotal: 2146758656
  uptime: 156h 28m 35.07s (Approximately 6.50 days)
registries:
  search:
  - registry.access.redhat.com
  - registry.redhat.io
  - docker.io
store:
  configFile: /etc/containers/storage.conf
  containerStore:
    number: 3
    paused: 0
    running: 3
    stopped: 0
  graphDriverName: overlay
  graphOptions:
    overlay.mountopt: nodev,metacopy=on
  graphRoot: /var/lib/containers/storage
  graphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Using metacopy: "true"
  imageStore:
    number: 9
  runRoot: /var/run/containers/storage
  volumePath: /var/lib/containers/storage/volumes
version:
  APIVersion: 3.0.0
  Built: 1614179610
  BuiltTime: Wed Feb 24 09:13:30 2021
  GitCommit: 1702cbc6917f431bcc65d6c5bdc6fcf99231977a-dirty
  GoVersion: go1.14.12
  OsArch: linux/amd64
  Version: 3.1.0-dev

Package info (e.g. output of rpm -q podman or apt list podman):

the podman on this machine is built locally from the podman latest code.

Have you tested with the latest version of Podman and have you checked the Podman Troubleshooting Guide?

Yes

Additional environment details (AWS, VirtualBox, physical, etc.):

[vrothberg]

Thanks for reaching out! @mheon opened #9512 to fix the issue.