Rudder

Currently, we use several different directories for ncf on root servers, relay servers and nodes:

• /usr/share/ncf/tree
  • ncf is installed here on the root server, from a package
  • this directory is shared for nodes and relay servers to copy from
    • nodes and relay servers copy this directory to their local /var/rudder/ncf/common
    • relay servers copy this directory to their local /usr/share/ncf/tree (yes, that's two identical but separate copies of the same directory to relay servers)
• /var/rudder/ncf/common
  • /usr/share/ncf/tree is copied into this directory by the agent, in update.cf so before a normal run
  • this directory is used to read the bundles in from promises.cf so during a normal run
• /var/rudder/configuration-repository/ncf
  • the local instance of ncf is instanciated here, in particular the local configuration file ncf.conf
  • the technique editor creates and modifies techniques here
  • this directory is shared for nodes and relay servers to copy from
    • nodes and relay servers copy this directory to their local /var/rudder/ncf/local
    • relay servers copy this directory to their local /var/rudder/configuration-repository/ncf (yes, that's two identical but separate copies of the same directory to relay servers)
• /var/rudder/ncf/local
  • /var/rudder/configuration-repository/ncf is copied into this directory by the agent, in update.cf so before a normal run
  • this directory is used to read the bundles in from promises.cf so during a normal run

We can largely simplify this.

Initial discussions showed several key points that we would like to achieve in simplifying this:

1. Simplify the copy mechanism so that all nodes, including relay and root servers, use the same directory for each item
2. Avoid duplication so that directories don't exist twice with identical contents on each folder
3. Avoid delays introduced by copying from one directory to another locally before a remote copy

The initial proposal for simplification is as follows:

• Keep /usr/share/ncf/tree as the installation directory, but don't share it any longer.
• Copy this directory on installation (in rudder-upgrade, and possibly rudder-init) to /var/rudder/configuration-repository/ncf.d/common
• Move /var/rudder/configuration-repository/ncf to /var/rudder/configuration-repository/ncf.d/local
• Suppress /var/rudder/ncf/local completely, and share /var/rudder/configuration-repository/ncf.d/local instead
• Configure both relay servers and nodes to only copy the /var/rudder/configuration-repository/ncf.d/ directory
• Change all promises to read ncf bundles from /var/rudder/configuration-repository/ncf.d/ only