Variables

[jimdowling]

In the ndb-chef recipe, I want to generate a public-private key in the mgmd-server node. Then, in the subsequent ndbd recipes (they come after the mgmd node in the DAG), i would like to pass in the public key to the mgmd node as a parameter (update .ssh/authorized_keys with the mgmd's public key), so that the mgmd node can ssh into the machines without a password.
However, there's no way of passing variables between recipes.
It would be nice to have a variable defined in the cluster file that is bound during recipe execution, and becomes available for subsequent recipes in the DAG. We could now only write the role.json file immediately before we run a recipe (not at the start like we currently do).

One way of implementing this would be for the receipe to generate an output file with modifications to the DAG. So, for example, if I want to set the public key of the mgmd as a variable for the next recipe, I would generate an output file ndb___mgmd.output:
node[:ndb][:mgmd][:public_key] = "........................"

Then Karamel can read in the file after the recipe executes, update the DAG, and execute the next recipe in the DAG.

[jimdowling]

Duplicate of #31 , closing.