system-config/doc/source/infra-cloud.rst

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Infra Cloud

Infra Cloud

Introduction

With donated hardware and datacenter space, we can run an optimized semi-private cloud for the purpose of adding testing capacity and also with an eye for "dog fooding" OpenStack itself.

Current Status

Currently this cloud is in the planning and design phases. This section will be updated or removed as that changes.

Mission

The infra-cloud's mission is to turn donated raw hardware resources into expanded capacity for the OpenStack infrastructure nodepool.

Methodology

Infra-cloud is run like any other infra managed service. Puppet modules and Ansible do the bulk of configuring hosts, and Gerrit code review drives 99% of activities, with logins used only for debugging and repairing the service.

Requirements

• Compute - The intended workload is mostly nodepool launched Jenkins slaves. Thus flavors that are capable of running these tests in a reasonable amount of time must be available. The flavor(s) must provide:

  • 8GB RAM
  • 8 * vcpu
  • 30GB root disk

• Images - Image upload must be allowed for nodepool.

• Uptime - Because there are other clouds that can keep some capacity running, 99.9% uptime should be acceptable.

• Performance - The performance of compute and networking in infra-cloud should be at least as good as, if not better than, the other nodepool clouds that infra uses today.

• Infra-core - Infra-core is in charge of running the service.

Implementation

Multi-Site

There are at least two "sites" with a collection of servers in each site. Each site will have its own cloud, and these clouds will share no infrastructure or data. The racks may be in the same physical location, but they will be managed as if they are not.

HP1

The HP1 site has 48 machines. Each machine has 96G of RAM, 1.8TiB of disk and 24 Cores of Intel Xeon X5650 @ 2.67GHz processors.

HP2

The HP2 site has 100 machines. Each machine has 96G of RAM, 1.8TiB of disk and 32 Cores of Intel Xeon E5-2670 0 @ 2.60GHz processors.

Software

Infra-cloud runs the most recent OpenStack stable release. During the period following a release, plans must be made to upgrade as soon as possible. In the future the cloud may be continuously deployed.

Management

• A "Ironic Controller" machine is installed by hand into each site. That machine is enrolled into the puppet/ansible infrastructure.
• The "Ironic Controller" will have bifrost installed on it. All of the other machines in that site will be enrolled in the Ironic that bifrost manages. bifrost will be responsible for booting base OS with IP address and ssh key for each machine.
• The machines will all be added to a manual ansible inventory file adjacent to the dynamic inventory that ansible currently uses to run puppet. Any metadata that the ansible infrastructure for running puppet needs that would have come from OpenStack infrastructure will simply be put into static ansible group_vars.
• The static inventory should be put into puppet so that it is public, with the IPMI passwords in hiera.
• An OpenStack Cloud with KVM as the hypervisor will be installed using OpenStack puppet modules as per normal infra installation of services.
• As with all OpenStack services, metrics will be collected in public cacti and graphite services. The particular metrics are TBD.
• As a cloud has a large amount of pertinent log data, a public ELK cluster will be needed to capture and expose it.
• All Infra services run on the public internet, and the same will be true for the Infra Clouds and the Ironic Clouds. Insecure services that need to be accessible across machine boundaries will employ per-IP iptables rules rather then relying on a squishy middle.

Architecture

The generally accepted "Controller" and "Compute" layout is used, with controllers running all non-compute services and compute nodes running only nova-compute and supporting services.

• The cloud is deployed with two controllers in a DRBD storage pair with ACTIVE/PASSIVE configured and a VIP shared between the two. This is done to avoid complications with Galera and RabbitMQ at the cost of making failovers more painful and under-utilizing the passive stand-by controller.
• The cloud will use KVM because it is the default free hypervisor and has the widest user base in OpenStack.
• The cloud will use Neutron configured for Provider VLAN because we do not require tenant isolation and this simplifies our networking on compute nodes.
• The cloud will not use floating IPs because every node will need to be reachable via routable IPs and thus there is no need for separation. Also Nodepool is under our control, so we don't have to worry about DNS TTLs or anything else causing a need for a particular endpoint to remain at a stable IP.
• The cloud will not use security groups because these are single use VMs and they will configure any firewall inside the VM.
• The cloud will use MySQL because it is the default in OpenStack and has the widest user base.
• The cloud will use RabbitMQ because it is the default in OpenStack and has the widest user base. We don't have scaling demands that come close to pushing the limits of RabbitMQ.
• The cloud will run swift as a backend for glance so that we can scale image storage out as need arises.
• The cloud will run keystone v3 and glance v2 APIs because these are the versions upstream recommends using.
• The cloud will not use the glance task API for image uploads, it will use the PUT interface because the task API does not function and we are not expecting a wide user base to be uploading many images simultaneously.
• The cloud will provide DHCP directly to its nodes because we trust DHCP.
• The cloud will have config drive enabled because we believe it to be more robust than the EC2-style metadata service.
• The cloud will not have the meta-data service enabled because we do not believe it to be robust.

Networking

Neutron is used, with a single provider VLAN attached to VMs for the simplest possible networking. DHCP is configured to hand the machine a routable IP which can be reached directly from the internet to facilitate nodepool/zuul communications.

Each site will need 2 VLANs. One for the public IPs which every NIC of every host will be attached to. That VLAN will get a publicly routable /23. Also, there should be a second VLAN that is connected only to the NIC of the Ironic Cloud and is routed to the IPMI management network of all of the other nodes. Whether we use LinuxBridge or Open vSwitch is still TBD.