Test Driven Infrastructure with Docker, Test Kitchen and Serverspec

Learn how to win at buzzword bingo by combining two popular testing tools with docker to create a test-driven infrastructure.

Transcript

1. Test Driven Infrastructure with Docker, Test Kitchen and Serverspec Yury Tsarev
2. Agenda ▸ Goal ▸ Test kitchen ▸ Docker driver ▸ kitchen-puppet provisioner ▸ Serverspec verifier ▸ Shellmocking ▸ Defining puppet type in kitchen ▸ Create test-driven infrastructure change ▸ Wrap-up
3. Goal ▸ Infrastructure code should be treated as any other code ▸ Apply TDD for puppet ▸ Grow regression test suite
4. Test kitchen ▸ http://kitchen.ci/ ▸ Test orchestrator ▸ Originated in Chef community ▸ Very pluggable on all levels ▸ "Your infrastructure deserves tests too." ▸ Book - Test-Driven Infrastructure with Chef
5. Test kitchen - high level process 1. Create VM/Container (docker driver) 2. Run configuration management code there (puppet provisioner) 3. Test with verifier (serverspec)
6. Main configuration file - .kitchen.yml ▸ Driver: what type of VM/containerization/cloud to use ▸ Provisioner: which configuration management tool to apply ▸ Verifier: test automation type to verify with ▸ Transport: mechanism to upload files into instance under test
7. Docker driver ▸ https://github.com/portertech/kitchen-docker ▸ kitchen driver to work with docker containers as machines under test driver: name: docker image: docker-registry.na.intgdc.com:80/gdc:R23 platform: rhel use_sudo: false provision_command: yum clean all && yum makecache
8. kitchen-puppet provisioner ▸ https://github.com/neillturner/kitchen-puppet ▸ Uploads puppet code into instance ▸ Runs puppet there (converge) ▸ Provides facts customization facility custom_facts: docker: 1 hostname: kitchen_test ec2data_branch: develop # pulp repo branch, critical for gitflow repo ec2data_gitbranch: develop # git branch ec2data_freeipa_otp: test ec2_public_ipv4: 127.0.0.1 ec2_local_ipv4: 127.0.0.1 has_mnt: 0
9. Serverspec test suite ▸ http://serverspec.org/ - RSpec based framework ▸ http://serverspec.org/resource_types.html ▸ Independent of kitchen - can be used standalone ▸ We keep test suite together with puppet code under spec directory to have ability to create consistent PRs describe file('/var/log/httpd') do it { should be_directory } end describe docker_image('busybox:latest') do its(['Architecture']) { should eq 'amd64' } end
10. Serverspec verifier: busser or shell ▸ Simple https://github.com/test-kitchen/busser-serverspec ▸ Advanced https://github.com/vincentbernat/serverspec-example
11. Serverspec verifier in GD ▸ Based on shell verifier and serverspec test suite ▸ Runs a serverspec test suite against the configured (converged) instance ▸ Reports in shell and junit - jenkins ready verifier: name: shell remote_exec: true command: | sudo -s <<SERVERSPEC export SERVERSPEC_ENV=$EC2DATA_ENVIRONMENT export SERVERSPEC_BACKEND=exec serverspec junit=true tag=~skip_in_kitchen check:role:$EC2DATA_TYPE SERVERSPEC
12. Transport ▸ https://github.com/coderanger/kitchen-sync ▸ Replaced default scp with sftp transport ▸ Reduced 1.5m to 5 sec for puppet and test suite upload!
13. Shellmocking ▸ To bypass external dependencies ▸ To bypass docker specific limitations ▸ Implementation located in puppet repo under spec/shellmock ▸ Simple ruby script ▸ Wraps yum invocation ▸ Mock is defined in simple yaml format: package: /path/to/executable: contents
14. Defining puppet type in kitchen ▸ Declare in platforms section of .kitchen.yml platforms: - name: zuul provisioner: custom_facts: ec2data_type: zuul ▸ kitchen converge ▸ pray ▸ shellmock ▸ repeat
15. Create test-driven infrastructure change ▸ Write serverspec expectation for new code ▸ kitchen verify <type> ▸ Observe related test is red ▸ Write puppet code ▸ kitchen converge <type> ▸ kitchen verify <type> ▸ Observe related test is green ▸ Commit the changes and create PR to puppet repo ▸ DEMO
16. Wrap-up: Benefits ▸ Scratch environment ▸ Test in isolation ▸ Easy to test permutations ▸ Resource efficiency ▸ Test-first/test-driven approach for infrastructure code ▸ Fast feedback - even before a commit ▸ Naturally growing regression test suite
17. Wrap-up: OSS side of things ▸ Multiple open source projects combined ▸ We contributed a lot into related kitchen projects and serverspec ▸ Nominated as kitchen-puppet core contributor
18. Wrap-up: What is next ? ▸ Define all types in kitchen ▸ with every next adopted type it will be easier ▸ Create smart way to test only related types for code change, a.k.a puppet dependency tracking
19. Wrap-up: A note on agnostic approach ▸ As the kitchen driver is agnostic to virtualization solution/cloud ▸ As the kitchen provisioner is agnostic to configuration management solution ▸ As the serverspec is agnostic to way to configure servers at all ▸ We are capable to make brave movements in future!
20. Wrap-up: Try it! ▸ http://kitchen.ci/ ▸ https://github.com/portertech/kitchen-docker ▸ https://github.com/neillturner/kitchen-puppet ▸ http://serverspec.org/