Automation - The Practice of Cloud System Administration - page 271

software, often working in partnership with a person. Automation starts by having a docu-
mented, well-defined, repeatable process. That document can be used to create scripts that
can be used as tools to speed upthe process and make it more reliable. Finally,the task can
befullyautomatedbycreatingaself-servicetooloraprocessthatisautomaticallytriggered
by changes in a database or configuration file. A self-service tool is particularly useful, as
it renders others self-sufficient. When something is automated, the SA's job changes from
doingthetasktomaintainingtheautomationthatdoesthetask.Amoreenlightenedwayof
thinking of automation is as a partner for operations rather than a replacement.
Many levels of automation exist, from fully manual to systems that work autonomously
without human veto or approval. Different levels are appropriate depending on the task
type and risk.
SAs can choose between scripting languages and compiled languages for creating auto-
mation. Understanding the benefits and disadvantages of each approach enables the SA to
choose the right tool for the job. Configuration management systems are also useful for
some forms of automation. Configuration management tools use a declarative syntax so
that you can specify what the end result should be; the CM tool then figures out how to
bring the system to that state.
Best practices dictate that all code for automation and configuration files be kept under
revision control or in a database that tracks changes. As is true for the software develop-
ment environment, automation tools should not be developed or tested in the production
environment. Instead, they should be developed in a dedicated development environment,
then staged to a testing area for quality assurance tests, before being pushed to the produc-
tion environment.
Exercises
1. List five benefits of automation. Which ones apply to your own environment and
why?
2. Document a process that needs automation in your current environment. Remem-
ber that the document should include every step needed to do the process!
3. Describe how to prioritize automation using a decision matrix.
4. When would you use a scripting language instead of a compiled language, and
why? In which circumstances would you use a compiled language for automation?
5. Imagine that you are going to implement a configuration management system in
your current environment. Which one would you choose and why?
6. What percentage of your time is spent on one-off tasks and operational work that is
not automated? What could you do to change this for the better?