Configure a Host (Archived 2024-04-14) #

DO NOT USE THIS - ONLY FOR REFERENCE - ALREADY AUTOMATED WITH MAAS

Host device minimum recommended hardware requirements

RAM: 16 GB
CPU: 4 cores

Configuring a new host is mostly automated using the provided Ansible scripts.

kthcloud uses an SSH jump host, so any IP specified for the hosts is a local IP.

Local machine #

Install Ansible #

Ansible needs to be installed on your local machine.

# Fedora, CentOS, RHEL
sudo dnf install ansible

# Ubuntu, Debian
sudo apt install ansible

# Arch
sudo pacman -S ansible

Install dependencies #

ansible-galaxy collection install community.general

Configure hosts #

Add the host to the Ansible inventory in inventory.yml

The IP address, hostname, password etc. can be extrapolated from the existing configurations in Credentials. For example, if 172.31.0.18 is the latest server, pick 172.31.0.19.

Hostname is in the format of rr-zzzz-XXX where r is region, z is zone and XXX is the machine ID. For example 172.31.0.11 has se-flem-001. It is preferred to have a matching IP and hostname in order to simplify administration and ssh, so 172.31.0.29 should have se-flem-019, etc.

Current regions: Sweden (se)

Current zones: Flemingsberg (flem)

FQDN is hostname.cloud.cbh.kth.se, so for example se-flem-001.cloud.cbh.kth.se

A list of generated but not yet allocated passwords are available at the bottom of the Credentials page.

kthcloud host appliance #

Flash ISO #

Flash a bootable ISO with the latest build of Ubuntu Server. 20.04 was used at the time of writing.

Install Ubuntu Server #

Select and format a disk, then configure a static IP address (as configured earlier in the Ansible inventory).

Network configuration

network: 172.31.0.0/16

address: 172.31.0.XX (as you chose in the steps above)

gateway: 172.31.83.1

nameservers: 1.1.1.1

Make sure to check Install OpenSSH server.

Fill out the name and credentials form as following:

Your name: cloud
Your server’s name: hostname in Ansible inventory
Pick a username: cloud
Choose a password: some generated password

No additional configuration is needed once the initial configuration is made.

**NB! **You must copy id and be able to SSH to the new machine from your local device before running Ansible.

Instructions for this can be found at Credentials under SSH-copy-id

This needs to be possible without any passwords being entered so both proxy host and destination hosts must have keys copied from your local machine.

Local machine #

Run the Ansible script to configure the host #

Make sure only the machines you want to configure are active in the inventory.

Make a machine inactive in the inventory by commenting it or removing it temporarily from the file.

Run the ansible playbook

ansible-playbook setup-host.yml -i inventory.yml

The destination computers may reboot after installing packages. If this occurs, a timeout may exit the ansible playbook prematurely.

If this is the case, when the machine is up (when you can ssh to it) simply run the playbook again using the same command as the first time so that it finishes properly.

Connect to CloudStack #

Adding a host to CloudStack can be done using the GUI or API. Adding through API is recommended if adding more than one host.

GUI #

Before adding a host, determine which cluster it should be added to. A cluster must contain hosts with homogeneous hardware, therefore if a cluster for the hardware model does not already exists, a new cluster must be created.

Adding a cluster #

If a new cluster is needed, navigate to Infrastructure > Clusters > Add Cluster + Fill in the form as shown in the image below. A cluster name should describe which hardware model it contains, eg. Precision 7920.

Adding a host #

Add a host by navigating to Infrastructure > Hosts > Add Host + Fill in the form as shown in the image below. If a new cluster was created, make sure it is visible in the Cluster name drop-down menu

API #

The API is accessed using CloudMonkey. See this this guide how to install CloudMonkey. Once installed, connect to the management server using:

(mycloud) 🐱 > set url http://dashboard.cloud.cbh.kth.se/client/api
(mycloud) 🐱 > set username <username>
(mycloud) 🐱 > set password <password>
(mycloud) 🐱 > sync

Since the current CloudStack configuration only contains one zone and one pod, Flemingsberg and LabRack, using zoneid=f80a25ea-1b23-4cad-9491-42c0ccd632e3 podid=00dee33d-e80f-400d-8814-ea0c32e7f5d1 podid=00dee33d-e80f-400d-8814-ea0c32e7f5d1 in the following API-calls is sufficient.

Before adding a host, determine which cluster it should be added to. A cluster must contain hosts with homogeneous hardware, therefore if the machine type does not already exists, a cluster must be created.

If a new cluster is needed, create it using the following API-call:

(mycloud) 🐱 > add cluster clustername=<hardware model name, eg. Precsion 7920> \
clustertype=CloudManaged hypervisor=KVM podid=<id> zoneid=<id>

Add hosts using the following API-call:

(mycloud) 🐱 > add host username=cloud password=<host password> hypervisor=KVM zoneid=<id> \
clusterid=<id, created before or if it already exists> url=http://<machine ip>

Troubleshooting #

Ansible can’t connect to the machine #

Install SSH keys on the machine by running the following command and change the local IP placeholder:

ssh-copy-id -o ProxyCommand="ssh -p 8022 -W %h:%p -q cloud@se-flem-001.cloud.cbh.kth.se" cloud@<local IP>

Error when deploying new instance in CloudStack #

Error message: VNC password is 22 characters long, only 8 permitted Newer version of libvirt shipped with Ubuntu Server 22.04 breaks CloudStack VNC implementation. This is fixed in CloudStack 4.17 as seen in this pull request, however until this version of CloudStack is used, downgrade to Ubuntu Server 20.04.