allow setting hostname for a pod

[chenzhiwei]

/kind feature

Description

When I run podman play kube pod.yaml to create a pod, the hostname is the last container's container-id.

My application is highly reply on hostname, is it possible to add a feature to podman pod to allow customizing the hostname? Or set the pod name as hostname?

Kubernetes Pod has a field hostname, it is better to use this as hostname.

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

Output of podman version:

host:
  BuildahVersion: 1.9.0
  Conmon:
    package: podman-1.4.4-2.el7.centos.x86_64
    path: /usr/libexec/podman/conmon
    version: 'conmon version 0.3.0, commit: unknown'
  Distribution:
    distribution: '"centos"'
    version: "7"
  MemFree: 15667200
  MemTotal: 521199616
  OCIRuntime:
    package: runc-1.0.0-64.rc8.el7.centos.x86_64
    path: /usr/bin/runc
    version: 'runc version spec: 1.0.1-dev'
  SwapFree: 138407936
  SwapTotal: 138407936
  arch: amd64
  cpus: 1
  hostname: host.localdomain
  kernel: 4.19.8-1.el7.elrepo.x86_64
  os: linux
  rootless: false
  uptime: 6h 25m 36.48s (Approximately 0.25 days)
registries:
  blocked: null
  insecure: null
  search:
  - registry.access.redhat.com
  - docker.io
  - registry.fedoraproject.org
  - quay.io
  - registry.centos.org
store:
  ConfigFile: /etc/containers/storage.conf
  ContainerStore:
    number: 3
  GraphDriverName: overlay
  GraphOptions: null
  GraphRoot: /var/lib/containers/storage
  GraphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "true"
    Supports d_type: "true"
    Using metacopy: "false"
  ImageStore:
    number: 4
  RunRoot: /var/run/containers/storage
  VolumePath: /var/lib/containers/storage/volumes

Output of podman info --debug:

(paste your output here)

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

[rhatdan]

@haircommander @QiWang19 Can you guys look into this?

[haircommander]

Ah I think this revealed a bug too, if a container is in a pod that shares a uts namespace, shouldn't all containers in the pod share the hostname of the infra container? cc @mheon

[rhatdan]

Yes.