I am currently deploying a new product and came across some problems to structure my Playbook and Roles. I have three different solutions and hope to get some input which path might be the best.
The product is a webapp on a windows server. The following steps are needed to deploy (high level):
- install javajdk
- install tomcat
- install win_service
- configure java regkes
- configure tomcat
- install webapp
- start service
I use static inventories for prod and staging, group_vars, roles (created with ansible-galaxy) so there is some kind of structure.
Solution 1Put everything in one huge playbook. That does not sound well, but has the advantage that you know the variables from previous installations e.g. tomcat needs to know where JAVA_HOME is... that was with the javajdk installation, due to more than one java on the machines there is no global JAVA_HOME...
Solution 2Break all out in small roles. Sounds great but roles should be independent from each other. I did not found a method to decouple tasks. Would it make sense to have single roles for e.g. install_tomcat, config_tomcat and set up a playbook which has the mentioned roles in sequence?
But how does one role know about, e.g. a path name which is needed in the next role. -> Installation sets the path, config needs to know.. I an really unsure to make roles independent.
Solution 3Kind of solution 2. Have a main playbook which contains only roles, split as much as possible to roles. Have independent variable names in ./roles/vars/main.yml
Somehow(?) find a place higher in the variable precedence with the playbook where all needed var definitions go. Internally either path a variable to the role or simply over-rule a role variable.
E.g. a product has a service, the service name is generally part of a path name for tomcat. The tomcat name should not depend on the service, so there should be a tomcat_install_path in the role but also a service_name with the product. So in case the playbook for the product is called the service name should be part of the name, the tomcat_install is called with a total different deployment there should be no fiddling with a service name.
I would go with Solution 3 but I have not yet found a way to set that up. What is the experts opinion, is solution 3 doable, is one of the other once better or is there a 4th solution?
