add rs.slaveOk to run before the getDBs call

[TomRitserveldt]

otherwise puppet runs fail on the slaves in a multi node replica mongo setup.
how this occurs from what I've been able to see:

provision 3 vm's:

• on the first vm the puppet runs succeeds, installing and configuring a mongodb with a replicaset and defining and setting up the required databases on that node. this node becomes the master.
• on the second vm during the puppet runs, puppet fetches a list of databases on the current mongo (replicaset),which returns the error:

Failed to apply catalog: Could not evaluate MongoDB shell command: printjson(db.getMongo().getDBs())

• the same occurs on the 3rd node, since this is a slave as well.

to fix this we must pass the rs.slaveOk() command before the printjson(db.getMongo().getDBs()), in order to allow the current connection to allow read operations to run on secondary members.
which I hope to solve with this pull request, if there are cleaner/better ways to fix this issue, I'm open to suggestions.

[rnelson0]

Is it possible to add a test for the behavior you're seeing with the 2nd and 3rd replicas? Otherwise, the code itself looks ok, but I don't have experience with mongoDB to know if it's an appropriate solution.

[rnelson0]

A quick google shows that replica sets replace master-slave, and the latter is deprecated starting in MongoDB 3.6. Again, I don't have experience with MongoDB, but it seems like maybe there are other solutions here, perhaps dependent on the version in use.

[bastelfreak]

Hoi @TomRitserveldt, thanks for the PR! Can you take a look at the comments from @rnelson0 ?

[TomRitserveldt]

Yes, I'm currently looking into some alternative ways to get around or fix this issue.
Some extra info regarding @rnelson0 comments:
Yes, replica sets are the desired way to go, but that is also what I'm already using.
With a replicaset setup you still have the primary and secondary concept, which requires you to use rs.slaveOk() to do read operations on the secondary nodes.
rs.slaveOk() also seems to have no impact at all when used on the primary node from what I've seen / tested.

[Dharmender-Singh]

@TomRitserveldt : Have you setup the replication with Auth Enabled or Disabled ? I am trying to setup with Auth enabled but getting following error :

Error: Failed to apply catalog: Could not evaluate MongoDB shell command: load('/root/.mongorc.js'); printjson(db.getMongo().getDBs())

[TomRitserveldt]

@Dharmender-Singh Sorry no I am setting it up without auth enabled.

[TomRitserveldt]

Any chance this could still get merged?
My earlier comment should have answered nelson's concern regarding if there's a better way to go about this, with the included link/reference to the mongodb docs there.