CVN Infrastructure

See CVN documentation on Meta-Wiki for a high-level overview of the infrastructure.

Server configuration

Our servers run at Wikimedia Cloud in a dedicated Nova project at https://wikitech.wikimedia.org/wiki/Nova_Resource:Cvn.

The setup.yaml file in this repository describes how all instances are configured. It is a bit like Puppet or Chef, except written for human interpretation. Though declared as brief as possible for unambiguous execution.

Legend:

• global @once section: Describes global dependencies that were set up once. This is mostly a description of the project's global state. These would have to be re-done in case of project re-creation.

• node @each section: Describes the steps that apply to all instances. These are run when creating new instances, such as web servers or application servers.

• debian steps: Install packages from the Ubuntu package repository (through apt-get install).

• services steps: Install these services by performing the steps under the relevant service section.

• setup steps: Perform these actions via Bash. May contain variables and interactive instructions (not a completely valid shell script). Uses {value} placeholders. The edit and create command refer to creation and editing of files on disk. Command exec {key} includes steps from the referred key within the same service or node section.

• Any steps with differt names (e.g. prepare) should be ignored until and unless they are referenced by an exec command.

MegaTable