OpenStack command line client tools for Pouta
This article describes using Pouta on the command line. If not done already, start by installing the OpenStack tools.
You can do most of the things you need in the OpenStack (Horizon) web interface of cPouta and ePouta. However, sometimes it is handier, or even necessary, to use command line tools. OpenStack is divided into subcomponents that each take care of specific tasks such as managing virtual machines, volumes or images. Each of these subcomponents has its own API which can be accessed either programmatically or in a terminal using the command line tools that are introduced in this chapter.
The command line tools are used to control your use of the service, so they should be installed either on your local laptop/desktop or another server which you will use to manage the service.
Using Pouta from the command line
This article lists some basic commands for some of the most common operations in OpenStack. For each of the operations, we show a command that uses the common OpenStack command line tool.
These minimun versions of the OpenStack commands should work with the current version of ePouta and cPouta (Stein).
python-openstackclient==3.18.0
python-cinderclient==4.2.0
python-glanceclient==2.16.0
python-heatclient==1.14.1
python-keystoneclient==3.19.0
python-neutronclient==6.12.0
python-novaclient==13.0.2
python-swiftclient==3.7.1
More information: OpenStackClient pip module
Info
You can install the latest versions of the OpenStackClient pip module since they are backwards compatible.
Openstack commands and help
openstack -h
You can get a list of the available OpenStack subcommands by appending "-h"
after the openstack command. If you wish to see the options for a specific
subcommand, add the command name after "help". For example:
openstack help server create
Adding a keypair
openstack keypair create --public-key <file> <name>
The first thing you should do is to generate a keypair. It will be used to access virtual machines. You can also optionally specify a public key you have previously generated, in which case the private key is the one you generated when the public key was generated.
Generate a key named "test" with a private key stored in "test.pem":
openstack keypair create test > test.pem
List available images
openstack image list
This command lists the images that are available for the user. This includes public images and images that the user has added.
List the available flavors
openstack flavor list
The flavor of a virtual machine defines its virtual hardware: how many cores, how much memory, and so on.
Launch a virtual machine
openstack server create --flavor <flavor> --image <image id> --key-name <key name> <name for machine>
This command has the minimum amount of information for launching a functioning virtual machine.
Info
The output of the command "openstack server create" shows also a password called adminPass. You do not need to store this password as is not used when connecting to the virtual machine. The virtual machine allows access to a user only if the user uses SSH keys.
Customize the virtual machine before launch
openstack server create --flavor <flavor> --image <image id> --key-name <key name> --user-data user-data.sh <name for machine>
The user-data.sh file can have extra commands to be executed automatically after the instance has been launched.
Below is an example content of the script file that would add a custom user in to the flavor and giving it the sudo rights:
#!/bin/sh
# Add a new user called boss
useradd -m boss
# Add the user to sudoers. No password is needed for sudo.
echo 'boss ALL=(ALL) NOPASSWD:ALL' > /etc/sudoers.d/boss
The script file can contain any arbitrary command, so some cautioness is recommended.
Note
Please note that the example does not contain addition of user authentication (public SSH key).
List instances
openstack server list
This will give a list of the user's instances and information related to them.
Terminate instances
openstack server delete <server>
This command shuts down and removes the machine. The running virtual machine is removed and cannot be recovered.
Associate public address
openstack floating ip create public
A public address must first be allocated from a pool of addresses. At this point, the IP address has not been assigned to any host.
openstack server add floating ip <server> <address>
This command assigns the address that was just allocated to a virtual machine.
When you no longer need the public address, you can release it to the public pool by deleting it.
openstack floating ip delete <address>
By doing this, you save billing units and maintain an efficient use of public IPs.
Authorization to connect to virtual machines
Create a new security group:
openstack security group create <security group name>
Add a rule to this new group that allows ping from a specific source network:
openstack security group rule create --proto icmp --remote-ip <source network> --dst-port 0 <security group name>
Add a rule that allows SSH from a specific source network:
openstack security group rule create --proto tcp --remote-ip <source network> --dst-port 22 <security group name>
Assign the newly created security group to your virtual server:
openstack server add security group <server> <security group name>
By default, all connections to virtual machines are blocked. This command allows ping and SSH access.
Server groups and affinity
Openstack has the option to create so-called server groups with specific affinity and anti-affinity rules. You specify if you want to use a specific group when launching a server.
A server group with an affinity rule guarantees that all virtual machines launched in the group are launched on the same physical server. A server group with an anti-affinity rule guarantees that all servers in the group are launched on different physical servers. If no suitable physical server is found, the virtual machine will not be created.
openstack server group create --policy <affinity or anti-affinity> <server group name>
After that, you can launch virtual machines in the group by specifying the group ID in the hint parameter.
openstack server create --flavor <flavor> --image <image id> --key-name <key name> --hint group=<server group id> <name for machine>
Check which virtual machines belong to the server group:
openstack server group show <server group id>