Docker compatibility: Container Inspect returns null for NetworkSettings.Networks

[candrews]

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

/kind bug

Description

The result of the ImageInspect API request:
GET /v1.30/images/curlimages%2Fcurl:latest/json
has NetworkSettings.Networks set to "null". That should not be the case. See https://docs.docker.com/engine/api/v1.30/#operation/ContainerInspect

Example docker API request: GET /v1.30/containers/7d6274e7015544739788b479d4d05a49e452a6e5c24a9e788c0e580b40524a21/json

And response:

{"Id":"7d6274e7015544739788b479d4d05a49e452a6e5c24a9e788c0e580b40524a21","Created":"2021-03-26T18:58:12.472132588-04:00","Path":"sh","Args":["-c","echo \\"root:$PASSWORD\\" | chpasswd \\u0026\\u0026 /usr/sbin/sshd -D -o PermitRootLogin=yes -o AddressFamily=inet -o GatewayPorts=yes"],"State":{"Status":"running","Running":true,"Paused":false,"Restarting":false,"OOMKilled":false,"Dead":false,"Pid":1144251,"ExitCode":0,"Error":"","StartedAt":"2021-03-26T18:58:12.831990779-04:00","FinishedAt":"0001-01-01T00:00:00Z"},"Image":"docker.io/testcontainers/sshd:1.0.0","ResolvConfPath":"/run/user/1000/overlay-containers/7d6274e7015544739788b479d4d05a49e452a6e5c24a9e788c0e580b40524a21/userdata/resolv.conf","HostnamePath":"/run/user/1000/overlay-containers/7d6274e7015544739788b479d4d05a49e452a6e5c24a9e788c0e580b40524a21/userdata/hostname","HostsPath":"/run/user/1000/overlay-containers/7d6274e7015544739788b479d4d05a49e452a6e5c24a9e788c0e580b40524a21/userdata/hosts","LogPath":"/home/candrews/.local/share/containers/storage/overlay-containers/7d6274e7015544739788b479d4d05a49e452a6e5c24a9e788c0e580b40524a21/userdata/ctr.log","Name":"/jovial_kowalevski","RestartCount":0,"Driver":"overlay","Platform":"linux","MountLabel":"system_u:object_r:container_file_t:s0:c792,c808","ProcessLabel":"system_u:system_r:container_t:s0:c792,c808","AppArmorProfile":"","ExecIDs":[],"HostConfig":{"Binds":[],"ContainerIDFile":"","LogConfig":{"Type":"json-file","Config":null},"NetworkMode":"slirp4netns","PortBindings":{"22/tcp":[{"HostIp":"","HostPort":"38423"}]},"RestartPolicy":{"Name":"","MaximumRetryCount":0},"AutoRemove":false,"VolumeDriver":"","VolumesFrom":null,"CapAdd":[],"CapDrop":["AUDIT_WRITE","MKNOD","NET_RAW"],"CgroupnsMode":"","Dns":[],"DnsOptions":[],"DnsSearch":[],"ExtraHosts":[],"GroupAdd":[],"IpcMode":"private","Cgroup":"","Links":null,"OomScoreAdj":0,"PidMode":"private","Privileged":false,"PublishAllPorts":false,"ReadonlyRootfs":false,"SecurityOpt":[],"UTSMode":"private","UsernsMode":"","ShmSize":65536000,"Runtime":"oci","ConsoleSize":[0,0],"Isolation":"","CpuShares":0,"Memory":0,"NanoCpus":0,"CgroupParent":"","BlkioWeight":0,"BlkioWeightDevice":null,"BlkioDeviceReadBps":null,"BlkioDeviceWriteBps":null,"BlkioDeviceReadIOps":null,"BlkioDeviceWriteIOps":null,"CpuPeriod":0,"CpuQuota":0,"CpuRealtimePeriod":0,"CpuRealtimeRuntime":0,"CpusetCpus":"","CpusetMems":"","Devices":[],"DeviceCgroupRules":null,"DeviceRequests":null,"KernelMemory":0,"KernelMemoryTCP":0,"MemoryReservation":0,"MemorySwap":0,"MemorySwappiness":0,"OomKillDisable":false,"PidsLimit":0,"Ulimits":[],"CpuCount":0,"CpuPercent":0,"IOMaximumIOps":0,"IOMaximumBandwidth":0,"MaskedPaths":null,"ReadonlyPaths":null},"GraphDriver":{"Data":{"LowerDir":"/home/candrews/.local/share/containers/storage/overlay/802b211bfc74359439a1f8383eb0fe7a14184a54bad35386832f753be750fdcb/diff:/home/candrews/.local/share/containers/storage/overlay/f566c57e6f2da2364c14195c832b922fd8f4813fd139b8fe45e3454c16e33975/diff","MergedDir":"/home/candrews/.local/share/containers/storage/overlay/7bd84c35dd88d4ef0a360a162fee9b69d4eb124e0c1156e13e51c8dc5ba515de/merged","UpperDir":"/home/candrews/.local/share/containers/storage/overlay/7bd84c35dd88d4ef0a360a162fee9b69d4eb124e0c1156e13e51c8dc5ba515de/diff","WorkDir":"/home/candrews/.local/share/containers/storage/overlay/7bd84c35dd88d4ef0a360a162fee9b69d4eb124e0c1156e13e51c8dc5ba515de/work"},"Name":"overlay"},"SizeRootFs":0,"Mounts":[],"Config":{"Hostname":"7d6274e70155","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"ExposedPorts":{"22/tcp":{}},"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin","TERM=xterm","container=podman","PASSWORD=01a30825-802d-4342-82f5-80b328b18343","HOME=/root","HOSTNAME=7d6274e70155"],"Cmd":["sh","-c","echo \\"root:$PASSWORD\\" | chpasswd \\u0026\\u0026 /usr/sbin/sshd -D -o PermitRootLogin=yes -o AddressFamily=inet -o GatewayPorts=yes"],"Image":"docker.io/testcontainers/sshd:1.0.0","Volumes":null,"WorkingDir":"/","Entrypoint":[],"OnBuild":null,"Labels":{"org.testcontainers":"true","org.testcontainers.sessionId":"a122b30f-c78b-462f-a9dd-6e9e87650d4a"},"StopSignal":"15","StopTimeout":0},"NetworkSettings":{"Bridge":"","SandboxID":"","HairpinMode":false,"LinkLocalIPv6Address":"","LinkLocalIPv6PrefixLen":0,"Ports":{"22/tcp":[{"HostIp":"","HostPort":"38423"}]},"SandboxKey":"/run/user/1000/netns/cni-f86e1703-0342-1c69-394d-045584856f96","SecondaryIPAddresses":null,"SecondaryIPv6Addresses":null,"EndpointID":"","Gateway":"","GlobalIPv6Address":"","GlobalIPv6PrefixLen":0,"IPAddress":"","IPPrefixLen":0,"IPv6Gateway":"","MacAddress":"","Networks":null}}

Note the "Networks":null in that response.

This results in an issue when using testcontainers, Testcontainers.exposeHostPorts results in an exception:
Cannot invoke "java.util.Map.values()" because the return value of "com.github.dockerjava.api.model.NetworkSettings.getNetworks()" is null

Here's socat output of the docker socket communication, captured by running: socat -v UNIX-LISTEN:/tmp/fake,fork UNIX-CONNECT:/run/user/1000/podman/podman.sock
socat-docker-socket.log

Steps to reproduce the issue:

I reproduced the issue by running testcontainers using the information provided at testcontainers/testcontainers-java#3934

Describe the results you received:
NetworkSettings.Networks is returned as null

Describe the results you expected:
NetworkSettings.Networks is populated

Additional information you deem important (e.g. issue happens only occasionally):
Discovered when using testcontainers: testcontainers/testcontainers-java#3934

Output of podman version:

podman version 3.1.0-rc2

Output of podman info --debug:

host:
  arch: amd64
  buildahVersion: 1.19.8
  cgroupManager: cgroupfs
  cgroupVersion: v1
  conmon:
    package: conmon-2.0.27-1.fc34.x86_64
    path: /usr/bin/conmon
    version: 'conmon version 2.0.27, commit: '
  cpus: 8
  distribution:
    distribution: fedora
    version: "34"
  eventLogger: journald
  hostname: craigatwork
  idMappings:
    gidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 100000
      size: 65536
    uidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 100000
      size: 65536
  kernel: 5.11.8-300.fc34.x86_64
  linkmode: dynamic
  memFree: 3268112384
  memTotal: 16647507968
  ociRuntime:
    name: crun
    package: crun-0.18-1.fc34.x86_64
    path: /usr/bin/crun
    version: |-
      crun version 0.18
      commit: 808420efe3dc2b44d6db9f1a3fac8361dde42a95
      spec: 1.0.0
      +SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +CRIU +YAJL
  os: linux
  remoteSocket:
    exists: true
    path: /run/user/1000/podman/podman.sock
  security:
    apparmorEnabled: false
    capabilities: CAP_CHOWN,CAP_DAC_OVERRIDE,CAP_FOWNER,CAP_FSETID,CAP_KILL,CAP_NET_BIND_SERVICE,CAP_SETFCAP,CAP_SETGID,CAP_SETPCAP,CAP_SETUID,CAP_SYS_CHROOT
    rootless: true
    seccompEnabled: true
    selinuxEnabled: true
  slirp4netns:
    executable: /usr/bin/slirp4netns
    package: slirp4netns-1.1.9-1.fc34.x86_64
    version: |-
      slirp4netns version 1.1.8+dev
      commit: 6dc0186e020232ae1a6fcc1f7afbc3ea02fd3876
      libslirp: 4.4.0
      SLIRP_CONFIG_VERSION_MAX: 3
      libseccomp: 2.5.0
  swapFree: 8108294144
  swapTotal: 16924008448
  uptime: 81h 25m 28.88s (Approximately 3.38 days)
registries:
  search:
  - registry.fedoraproject.org
  - registry.access.redhat.com
  - docker.io
  - quay.io
store:
  configFile: /home/candrews/.config/containers/storage.conf
  containerStore:
    number: 9
    paused: 0
    running: 7
    stopped: 2
  graphDriverName: overlay
  graphOptions:
    overlay.mount_program:
      Executable: /usr/bin/fuse-overlayfs
      Package: fuse-overlayfs-1.4.0-3.fc34.x86_64
      Version: |-
        fusermount3 version: 3.10.2
        fuse-overlayfs: version 1.4
        FUSE library version 3.10.2
        using FUSE kernel interface version 7.31
  graphRoot: /home/candrews/.local/share/containers/storage
  graphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Using metacopy: "false"
  imageStore:
    number: 10
  runRoot: /run/user/1000
  volumePath: /home/candrews/.local/share/containers/storage/volumes
version:
  APIVersion: 3.1.0-rc2
  Built: 1616550335
  BuiltTime: Tue Mar 23 21:45:35 2021
  GitCommit: ""
  GoVersion: go1.16
  OsArch: linux/amd64
  Version: 3.1.0-rc2

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

podman-3.1.0-0.2.rc2.fc34.x86_64

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.):

physical

[candrews]

This issue appears to be related to #6803

NetworkSettings.Networks was set to nil in https://github.com/containers/podman/pull/6852/files#diff-00600f2049a889a68d02d52f0b7f8a3b5dfcd9e9ba4499b66fa830f56f0dc3b1R401

[rhatdan]

Care to open a PR to attempt to fix this?

[candrews]

Care to open a PR to attempt to fix this?

I really want to, and started to look into doing so... but it's a lot to learn. I don't entirely understand what many of the Networks data structure fields are, and those that I do understand, I can't figure out where/how to get that data in podman.

[github-actions]

A friendly reminder that this issue had no activity for 30 days.

[rhatdan]

@Luap99 Care to look at this one?