Podman containers on Windows cannot connect to the host via localhost

[flibustier7seas]

Issue Description

Podman containers on Windows cannot connect to the host via localhost.

Steps to reproduce the issue

Invoke-WebRequest -Uri http://localhost:5079 | Select-Object StatusCode

# StatusCode
# ----------
#        200


docker run --rm --network host curlimages/curl -I -X GET http://localhost:5079

#   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
#                                  Dload  Upload   Total   Spent    Left  Speed
#   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0HTTP/1.1 200 OK
#   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
# Content-Type: application/json; charset=utf-8
# Date: Sat, 23 Nov 2024 13:31:55 GMT
# Server: Kestrel
# Transfer-Encoding: chunked

podman run --rm --network host curlimages/curl -I -X GET http://localhost:5079

#   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
#                                  Dload  Upload   Total   Spent    Left  Speed
#   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
# curl: (7) Failed to connect to localhost port 5079 after 0 ms: Could not connect to server

Describe the results you received

Podman container cannot connect to a port exposed on the host via localhost.

Describe the results you expected

Podman container can connect to a port exposed on the host via localhost.

podman info output

host:
  arch: amd64
  buildahVersion: 1.38.0
  cgroupControllers: []
  cgroupManager: cgroupfs
  cgroupVersion: v1
  conmon:
    package: conmon-2.1.12-2.fc40.x86_64
    path: /usr/bin/conmon
    version: 'conmon version 2.1.12, commit: '
  cpuUtilization:
    idlePercent: 99.8
    systemPercent: 0.1
    userPercent: 0.1
  cpus: 20
  databaseBackend: sqlite
  distribution:
    distribution: fedora
    variant: container
    version: "40"
  eventLogger: journald
  freeLocks: 1991
  hostname: MyPC
  idMappings:
    gidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 524288
      size: 65536
    uidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 524288
      size: 65536
  kernel: 5.15.167.4-microsoft-standard-WSL2
  linkmode: dynamic
  logDriver: journald
  memFree: 15142686720
  memTotal: 16626593792
  networkBackend: netavark
  networkBackendInfo:
    backend: netavark
    dns:
      package: aardvark-dns-1.12.2-2.fc40.x86_64
      path: /usr/libexec/podman/aardvark-dns
      version: aardvark-dns 1.12.2
    package: netavark-1.12.2-1.fc40.x86_64
    path: /usr/libexec/podman/netavark
    version: netavark 1.12.2
  ociRuntime:
    name: crun
    package: crun-1.18.2-1.fc40.x86_64
    path: /usr/bin/crun
    version: |-
      crun version 1.18.2
      commit: 00ab38af875ddd0d1a8226addda52e1de18339b5
      rundir: /run/user/1000/crun
      spec: 1.0.0
      +SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +CRIU +LIBKRUN +WASM:wasmedge +YAJL
  os: linux
  pasta:
    executable: /usr/bin/pasta
    package: passt-0^20241030.gee7d0b6-1.fc40.x86_64
    version: |
      pasta 0^20241030.gee7d0b6-1.fc40.x86_64
      Copyright Red Hat
      GNU General Public License, version 2 or later
        <https://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
      This is free software: you are free to change and redistribute it.
      There is NO WARRANTY, to the extent permitted by law.
  remoteSocket:
    exists: true
    path: unix:///run/user/1000/podman/podman.sock
  rootlessNetworkCmd: pasta
  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
    seccompProfilePath: /usr/share/containers/seccomp.json
    selinuxEnabled: false
  serviceIsRemote: true
  slirp4netns:
    executable: ""
    package: ""
    version: ""
  swapFree: 4294967296
  swapTotal: 4294967296
  uptime: 0h 30m 26.00s
  variant: ""
plugins:
  authorization: null
  log:
  - k8s-file
  - none
  - passthrough
  - journald
  network:
  - bridge
  - macvlan
  - ipvlan
  volume:
  - local
registries:
  search:
  - docker.io
store:
  configFile: /home/user/.config/containers/storage.conf
  containerStore:
    number: 45
    paused: 0
    running: 0
    stopped: 45
  graphDriverName: overlay
  graphOptions: {}
  graphRoot: /home/user/.local/share/containers/storage
  graphRootAllocated: 1081101176832
  graphRootUsed: 9572601856
  graphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "true"
    Supports d_type: "true"
    Supports shifting: "false"
    Supports volatile: "true"
    Using metacopy: "false"
  imageCopyTmpDir: /var/tmp
  imageStore:
    number: 21
  runRoot: /run/user/1000/containers
  transientStore: false
  volumePath: /home/user/.local/share/containers/storage/volumes
version:
  APIVersion: 5.3.0
  Built: 1731456000
  BuiltTime: Wed Nov 13 01:00:00 2024
  GitCommit: ""
  GoVersion: go1.22.7
  Os: linux
  OsArch: linux/amd64
  Version: 5.3.0
  Version: 5.3.0

Podman in a container

No

Privileged Or Rootless

Rootless

Upstream Latest Release

No

Additional environment details

podman version

# Client:       Podman Engine
# Version:      5.2.5
# API Version:  5.2.5
# Go Version:   go1.23.2
# Git Commit:   10c5aa720d59480bc7edad347c1f5d5b75d4424f
# Built:        Wed Oct 23 19:54:08 2024
# OS/Arch:      windows/amd64
# 
# Server:       Podman Engine
# Version:      5.3.0
# API Version:  5.3.0
# Go Version:   go1.22.7
# Built:        Wed Nov 13 01:00:00 2024
# OS/Arch:      linux/amd64

podman machine inspect

# [
#      {
#           "ConfigDir": {
#                "Path": "C:\\Users\\MyUser\\.config\\containers\\podman\\machine\\wsl"
#           },
#           "ConnectionInfo": {
#                "PodmanSocket": null,
#                "PodmanPipe": {
#                     "Path": "\\\\.\\pipe\\podman-machine-default"
#                }
#           },
#           "Created": "2024-11-21T11:45:15.1653755+01:00",
#           "LastUp": "2024-11-23T14:25:53.592163+01:00",
#           "Name": "podman-machine-default",
#           "Resources": {
#                "CPUs": 10,
#                "DiskSize": 100,
#                "Memory": 2048,
#                "USBs": []
#           },
#           "SSHConfig": {
#                "IdentityPath": "C:\\Users\\MyUser\\.local\\share\\containers\\podman\\machine\\machine",
#                "Port": 58684,
#                "RemoteUsername": "user"
#           },
#           "State": "running",
#           "UserModeNetworking": false,
#           "Rootful": false,
#           "Rosetta": false
#      }
# ]

wsl --version

# WSL version: 2.3.26.0
# Kernel version: 5.15.167.4-1
# WSLg version: 1.0.65
# MSRDC version: 1.2.5620
# Direct3D version: 1.611.1-81528511
# DXCore version: 10.0.26100.1-240331-1435.ge-release
# Windows version: 10.0.22631.4460

Additional information

Additional information like issue happens only occasionally or issue happens with a particular architecture or on a particular setting

[userid0x0]

I stepped somehow in a similar issue. First of all I think you need to use host.docker.internal / host.containers.internal instead of localhost.
I noticed a difference between Windows and Linux here. On Windows the host.docker.internal / host.containers.internal IPs address the WSL2 VM in background. Thus I am using the following batch snippet to workaround the problem (based on [1]).

SET WSLCMD=wsl -d podman-machine-default -u root

FOR /F %%i IN ('powershell "Get-NetIpAddress | where { $_.InterfaceAlias -Like '*WSL*' -and $_.AddressFamily -EQ 'IPv4' } |select -ExpandProperty IPAddress"') DO set WSLIP=%%i
%WSLCMD% sh -c "sed -i '/^host_containers_internal_ip/d' /etc/containers/containers.conf"
%WSLCMD% sh -c "sed -i '/\[containers\]/a host_containers_internal_ip = \"%WSLIP%\"' /etc/containers/containers.conf"

In cleartext - set the host_containers_internal_ip setting to match the WSL bridge network ip from windows.

[1] https://stackoverflow.com/questions/79098571/podman-container-cannot-connect-to-windows-host

[flibustier7seas]

First of all I think you need to use host.docker.internal / host.containers.internal instead of localhost.

Thank you for your suggestion, but unfortunately, I have to use localhost as it's a convention in our setup. All our services have dev/local configurations where URLs to other services use localhost, so developers can run everything locally in IDE/Docker/Podman, and the services communicate with each other via localhost.