Control a MongoDB collection in configuration management

This post explains how to use configuration management (Salt Stack) to completely control a MongoDB collection. In our example we want to control a store's collection of plans.

First we create a JSON representation of the collection.

mongodb/plan.json:

{
  "_id" : { "$oid" : "4ef8b9e2be329f491d98f74b" },
  "cost" : 20, "description" : "development",
  "name" : "good", "count" : 6000
}
{
  "_id" : { "$oid" : "4ef8b9e8be329f491d98f74c" },
  "cost" : 60, "description" : "freelancers",
  "name" : "better", "count" : 36000
}
{
  "_id" : { "$oid" : "4ef8b9f0be329f491d98f74d" },
  "cost" : 180, "description" : "production",
  "name" : "best", "count" : 162000
}

Next we configure a salt state formula to manage the JSON file and watch it for changes.

mongodb/init.sls:

# install mongodb server
mongodb-server:
  pkg:
    - installed

# manage the store's plan.json
/tmp/plan.json:
  file.managed:
    - source: salt://mongodb/plan.json
    - user: root
    - group: root
    - mode: 644

# import the plan collection if it changes
import-plan-collection:
    cmd.wait:
      - name: mongoimport --db=store --collection=plan --upsert /tmp/plan.json
      - require:
        - pkg: mongodb-server
      - watch:
        - file: /tmp/plan.json

Now whenever plan.json is altered in configuration management, the file on the minion will update which will trigger a mongoimport with upsert to occur.

Optionally, we could replace --upsert with --drop which will drop the collection before re-importing thus removing stale records.

We now have a version controlled JSON file in configuration management and the power of MongoDB Document Objects in our application code!