Generating/managing config files for hosted application
- by mfinni
I asked a question about config management, and haven't seen a reply. It's possible my question was too vague, so let's get down to brass tacks. Here's the process we follow when onboarding a new customer instance into our hosted application : how would you manage this? I'm leaning towards a Perl script to populate templates to generate shell scripts, config files, XML config files, etc. Looking briefly at CFengine and Chef, it seems like they're not going to reduce the amount of work, because I'd still have to manually specify all of the changes/edits within the tool. Doesn't seem to be much of a gain over touching the config files directly.
We add a stanza to the main config file for the core (3rd-party) application. This stanza has values that
defines the instance (customer) name
the TCP listener port for this instance (not one currently used)
the DB2 database name (serial numeric identifier, already exists, they get prestaged for us by the DBAs)
three sub-config files, by name - they need to be created from 3 templates and be named after the instance
The sub-config files define:
The filepath for the DB2 volumes
The filepath for the storage of objects
The filepath for just one of the DB2 volumes (yes, redundant to the first item.
We run some application commands, start the instance
We do some LDAP thingies (make an OU for the instance, etc.)
We add a stanza to the config file for our security listener that acts as a passthrough to LDAP
instance name
LDAP OU
TCP port for instance
DB2 database name
We restart the security listener (off-hours), change the main config file from item 1, stop and restart the instance. It is now authenticating via LDAP.
We add the stop and start commands for this instance to the HA failover scripts.
We import an XML config file into the instance that defines things for the actual application for the customer - user names, groups, permissions, and business rules. The XML is supplied by the implementation team.
Now, we configure the dataloading application
We add a stanza to the existing top-level config file that points to a new customer-level config file. The new customer-level config file includes:
the instance (customer) name
the DB2 database name
arbitrary number of sub-config files, by name
Each of the sub-config files defines:
filepaths to the directories for ingestion, feedback, backup, and failure
those filepaths have a common path to a customer-specific folder, and then one folder for each sub-config file
Each of those filepaths needs to be created
We need to add this customer instance to our monitoring scripts that confirm the proper processes are running and can be logged into. Of course, those monitoring config files include the instance name, the TCP port, the DB2 database name, etc.
There's also a reporting application that needs to be configured for the new instance. You get the idea.
There's also XML that is loaded into WAS by the middleware team. We give them the values for them to plug into the XML - they could very easily hand us the template and we could give them back completed XML.
