TDD For Ops – Christopher Webber / @cwebber

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TDD For Ops – Christopher Webber / @cwebber

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ladevops-tdd_for_ops

Preso on TDD for Ops at LA DevOps

On Github cwebberOps / ladevops-tdd_for_ops

TDD For Ops

Christopher Webber / @cwebber

About Me

Background

  • Always been in Ops or Support
  • Until recently, I have never really worked closely with developers
  • I have been doing Puppet since 2008 (v 0.24.7)
  • First looked at testing Puppet modules about a year ago

Outline

  • Why Testing
  • What is Testing
  • What to Test
  • Next Steps

Why Testing

What I Thought?

  • Help catch mistakes
  • Test that things work

Why Didn't I Start Writing Tests Regularly?

  • I was basically reimplementing my manifests in rspec
  • No guidance on what to test and why to test
  • Wait a sec, you mean it doesn't actually test if it works?
  • Didn't understand the types of tests

So Then Why Are We Here?

  • Testing configuration beyond just the manifests
  • Manifests are getting more complicated
  • Knowing that integration testing is coming
  • Makes writing Puppet code more fun

What is Testing

Types of Tests

  • Syntax Checking
  • Linting
  • Unit Tests
  • Integration Tests

Syntax Checking

  • Something a lot of us have done for a while
  • Important, but doesn't do much

Linting

  • puppet-lint and food critic
  • Makes reading manifests and code easier
  • Reminds you to do things like documentation

Unit Tests

  • rspec-puppet
  • Multiple tools in Chef
  • Test the code returns the things that are expected
  • In Puppet, testing the catalog
  • Get syntax checking for free

Integration Tests

  • Does the catalog actually apply or the run converge?
  • Did it actually work?

When To Test

It Is Driving Development, Right?

  • Before you start writing config mgmt code
  • After you found a problem in dev/prod
  • As you go

What To Test

Basic Stuff

  • Are the packages getting marked for install?
  • Is the config file getting put in the right place for this platform?
  • Is the service being started?

Puppet Code

package {'httpd':
  ensure => installed
}

rspec-puppet

it { should contain_package('httpd').with_ensure('installed') }

Important Config Elements

  • Is the Include directive in the apache config?
  • How about that Rewrite rule?
  • Are the search domains in the right order?
  • Are we setting the right options for SOLR?

Puppet Code

file {'/etc/ssh/sshd_config':
  ensure  => present,
  mode    => '0644',
  owner   => 'root',
  group   => 'root',
  content => template('ssh/etc/ssh/sshd_config.erb')
}

rspec-puppet

it do
 should contain_file('/etc/ssh/sshd_config') \
   .with_mode('0644') \
   .with_owner('root')
end

FAIL

Let's Try That Again

it "Enable GSSAPI" do
  should contain_file('/etc/ssh/sshd_config') \
    .with_content(/^GSSAPIAuthentication yes/)
end

it "Enable X11 Forwarding" do
  should contain_file('/etc/ssh/sshd_config') \
    .with_content(/^X11Forwarding yes/)
end

Security Considerations

  • Is logging enabled?
  • Are we disabling display_errors in PHP?

rspec-puppet

it "Disable root login via ssh" do
  should contain_file('/etc/ssh/sshd_config') \
    .with_content(/^PermitRootLogin no/)
end

Environment Differences

  • Is caching on in prod but off in dev?
  • Is debug on in dev but off in prod?

Show me on the doll where the config touched you...

  • A place to document those silly config changes and test them
  • Make sure the same mistake doesn't happen twice

rspec-puppet

it "Stop fucking alerting that ssh is down" do
  should contain_file('/etc/ssh/sshd_config') \
    .with_content(/^MaxStartups 40/)
end

Code Coverage

Next Steps

  • Automation via Continuous Integration
  • Integration testing (Test Kitchen)
  • Nagios/Monitoring Integration

Questions?

Resources

Talks

Puppet

Chef