ubuntu，RHEL和任何云映像的登录密码

Question

OpenStack cloud Images :

There are multiple cloud images which are available at https://docs.openstack.org/image-guide/obtain-images.html . In order to login to the VMs once those are deployed is either by using ssh key pair or password . But there are images where the sshkeypairlogin is disabled and there is no in-built password by default, then how to login to these VMs where the user have only information on the user-name

Answer 1

There are options to generate the password for the in-built users using cloud-init :

Option-1 : Using OpenStack horizon

If the user is using horizon to launch the instance then for the post-configuration by providing the config as:

    #cloud-config
    chpasswd:
      list: |
        cloud-user:rhel
        root:rheladmin
      expire: False

Here the passwords are generated for cloud-user and root users of RHEL image. The same is used for any user of any image simply by replacing the user.

Option-2 : Using OpenStack heat template

Using the openstack heat template by providing the user-data as below:

heat_template_version: 2015-04-30

description: Launch the RHEL VM with a new password for cloud-user and root user

resources:
  rhel_instance:
    type: OS::Nova::Server
    properties:
      name: 'demo_instance'
      image: '15548f32-fe27-449b-9c7d-9a113ad33778'
      flavor: 'm1.medium'
      availability_zone: zone1
      key_name: 'key1'
      networks:
      - network: '731ba722-68ba-4423-9e5a-a7677d5bdd2d'
      user_data_format: RAW
      user_data: |
        #cloud-config
        chpasswd:
          list: |
            cloud-user:rhel
            root:rheladmin
          expire: False

Here the passwords are generated for cloud-user and root users of RHEL image. The same is used for any user of any image.