Ansible playbooks to install a complete ComputeStacks installation

Before proceeding, be sure to review our architecture overview, and our minimum requirements. We are also more than happy to help you design your ComputeStacks environments. Please contact us to learn more.

Local Machine Prerequisites

• make (installed by default on all linux & mac systems)
• ansible

Once ansible is installed, run:

make roles

Please first check and see if terraform scripts exist for your platform. This is will greatly aid in building your inventory file and ensuring a more successful installation process.

Inventory File

If you used one of our terraform setup scripts (RECOMMENDED) to create your cluster, then you should already have a skeleton inventory.yml file that you can place in this directory. Otherwise, cp inventory.yml.sample inventory.yml.

Ensure you fill out all the variables and ensure everything is correct. To see all available settings, check each role and look at their defaults/main.yml file.

DNS

Various parts of this ansible package will require the domains defined in your inventory.yml file to be correctly setup. Please configure those domains and ensure the changes have been propagated before proceeding.

Example DNS Settings

a.dev.cmptstks.net. IN A %{PUBLIC IP OF NODE}
metrics.dev.cmptstks.net. IN A %{PUBLIC IP OF METRICS SERVER}
*.a.dev.cmptstks.net. IN CNAME a.dev.cmptstks.net.
portal.dev.cmptstks.net. IN A %{controller ip address}
cr.dev.cmptstks.net. IN CNAME portal.dev.cmptstks.net.

Requirements for each server

Server Hostnames (Skip if you used Terraform)

Ensure all hostnames are configured properly on each node. Our system expects the hostnames on nodes to be 1 lowercase word (dashes or underscores are ok), no special characters or spaces. They should not be FQDN or have the dot notation.

Example using node101, node102, node103

hostname node101 && echo "node101" > /etc/hostname && echo "127.0.0.1 node101" >> /etc/hosts

Install the following packages (Skip if you used Terraform)

Required packages when NOT using our terraform provisioners

apt-get update
apt-get -y install openssl \
                   ca-certificates \
                   linux-headers-amd64 \
                   python3 \
                   python3-pip \
                   python3-openssl \
                   python3-apt \
                   python3-setuptools \
                   python3-wheel

---

Running the installer

Bootstrap A New Cluster

make bootstrap

The last step in this script will reboot servers to finalize configuration.

Post-Installation

After running and allowing the servers to reboot, you can perform some basic validation by running:

make validate

Add Region / Availability Zone

To add a new region or availability zone, make a copy of your previous inventory.yml file and make the following changes:

1. Change region_name and/or, availability_zone_name
2. Replace all nodes with your new nodes
3. (optional) Change metrics / backup servers. You can re-use the existing ones if you wish.

Re-run the bootstrap command:

make bootstrap

FAQ

How to install ansible

Mac OSX

Install Homebrew

brew install ansible

Linux

Install pyenv for your local (non-root) user account.

You can set the new version with pyenv global 3.9.1 (replace 3.9.1 with the version you installed)

python -m pip install --user ansible
echo 'export PATH="$PATH:$HOME/.local/bin"' >> ~/.bashrc

Note: Check if you have a .bashrc file, it may be .bash_profile for your distribution.

This will ensure you have the most recent version of ansible.

Enable Swap Limit

In order to allow swap limitations set on containers, you need to perform the following on each node:

1. Modify the file /etc/default/grub
2. Add cgroup_enable=memory swapaccount=1 to the existing GRUB_CMDLINE_LINUX_DEFAULT setting
3. run update-grub
4. reboot

Note: This can add about 1% of overhead.

Troubleshooting

NetworkManager Hostname Error

How to Resolve set-hostname: current hostname was changed outside NetworkManager: '<hostname>' in logs:

Edit /etc/NetworkManager/NetworkManager.conf and add hostname-mode=none to the [main] block, and reboot the server.

Example:

[main]
#plugins=ifcfg-rh,ibft
hostname-mode=none