VMware Photon OS with PowerCLI

Photon OS is linux distribution maintained by VMware with multiple benefits for virtualized form factor, therefore any virtual appliance should be based on Photon OS.

I have recently tried to play with Photon OS and here are some my notes.

IP Settings

Network configuration files are in directory

/etc/systemd/network/

IP settings are leased from DHCP by default. It is configured in file  /etc/systemd/network/10-dhcp-en.network

File contains following config

[Match]
Name=e*
[Network]
DHCP=yes

To use static IP settings it is good to move DHCP config file down in alphabetical order and create config file with static IP settings.

mv 10-dhcp-en.network 99-dhcp-en.networkcp 99-dhcp-en.network 10-static-en.network

file  /etc/systemd/network/10-static-en.network should looks similar to

[Match]Name=eth0

[Network] 

Address=192.168.4.56/24 

Gateway=192.168.4.254 

DNS=192.168.4.4

Network can be restarted by command

systemctl restart systemd-networkd

and network settings can be checked by command

networkctl

Package management

Photon OS uses TDNF  (Tiny DNF) package manager. It is based on Fedora's DNF.  This is a development by VMware that comes with compatible repository and package management capabilities. Note that not every dnf command is available but the basic ones are there.

Examples:

• tdnf install libxml2
• tdnf install openssl-devel
• tdnf install binutils
• tdnf install pkg-config
• tdnf perl-Crypt-SSLeay
• tdnf install cpan
• tdnf libuuid-devel
• tdnf install make

Update of the whole operating system can be done by command

tdnf update

Log Management

You will not find typical linux /var/log/messages
Instead, journald is used and you have to use command journalctl

Equivalent to tail -f /var/log/messages is

journalctl -f 

System services

System services are control by command systemctl

To check service status use

systemctl status docker

To start service use

systemctl start docker

To enable service after system start use

systemctl enable docker

Docker and containerized PowerCLI

One of key use cases for Photon OS is to be a docker host, therefore, docker is preinstalled in Photon OS. You can see further Docker information by command

docker info

If Docker is running on your system, you can very quickly spin up docker container. Let's use example of containerized PowerCLI. To download container image from DockerHup use command

docker pull vmware/powerclicore

to check all downloaded images use the command

docker images -a   

 root@photon-machine [ ~ ]# docker images -a    
 REPOSITORY      TAG         IMAGE ID      CREATED       SIZE  
 vmware/powerclicore  latest       a8e3349371c5    6 weeks ago     610 MB  
 root@photon-machine [ ~ ]#   

Now you can run powercli container interactively (-i) and in allocated pseudo-TTY (-t). Option -rm stands for "Automatically remove the container when it exits".

docker run --rm -it vmware/powerclicore 

 root@photon-machine [ ~ ]# docker run --rm -it --name powercli vmware/powerclicore         
 PowerShell   
 Copyright (C) Microsoft Corporation. All rights reserved.erclicore --name powercl  
      Welcome to VMware vSphere PowerCLI!  
 Log in to a vCenter Server or ESX host:       Connect-VIServer  
 To find out what commands are available, type:    Get-VICommand  
 Once you've connected, display all virtual machines: Get-VM  
     Copyright (C) VMware, Inc. All rights reserved.  
 Loading personal and system profiles took 3083ms.  
 PS /powershell#   

Now you can use PowerCLI running on linux container. The very first PowerCLI command is usually Connect-VIServer, but you can get following warning and error messages

 PS /powershell> Connect-VIServer                                                                         
 cmdlet Connect-VIServer at command pipeline position 1  
 Supply values for the following parameters:  
 Server: vc01.home.uw.cz  
 Specify Credential  
 Please specify server credential  
 User: cdave  
 Password for user cdave: *********  
 WARNING: Invalid server certificate. Use Set-PowerCLIConfiguration to set the value for the InvalidCertificateAction option to Prompt if you'd like to connect once or to add  
  a permanent exception for this server.  
 Connect-VIServer : 06/07/2017 19:25:44     Connect-VIServer          An error occurred while sending the request.       
 At line:1 char:1  
 + Connect-VIServer  
 + ~~~~~~~~~~~~~~~~  
   + CategoryInfo     : NotSpecified: (:) [Connect-VIServer], ViError  
   + FullyQualifiedErrorId : Client20_ConnectivityServiceImpl_Reconnect_Exception,VMware.VimAutomation.ViCore.Cmdlets.Commands.ConnectVIServer  
 PS /powershell>   

To solve the problem you have to adjust PowerCLI configuration by

Set-PowerCLIConfiguration -InvalidCertificateAction ignore -confirm:$false -scope All

The command above changes PowerCLI configuration for all users.

To use other docker commands you can open another ssh session, and for example list running containers

 root@photon-machine [ ~ ]# docker ps -a     
 CONTAINER ID    IMAGE         COMMAND       CREATED       STATUS       PORTS        NAMES  
 6ecccf77891e    vmware/powerclicore  "powershell"    7 minutes ago    Up 7 minutes              powercli  
 root@photon-machine [ ~ ]#   

... or issue any other docker command.

That's cool, isn't it?