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Enjoying the Journey from Puppet 3.x to Puppet 4.x (PuppetConf 2016)

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Let's describe the process for upgrading from Puppet 3 to 4, list some common pitfalls and how to avoid them, and be sure to enjoy ourselves in the process!

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Enjoying the Journey from Puppet 3.x to Puppet 4.x (PuppetConf 2016)

  1. 1. Enjoying the Journey from Puppet 3.x to Puppet 4.x Rob Nelson
  2. 2. Who Am I? Puppet user since 2014 (3.3 era) Vox Pupuli, puppet-lint contributor @rnelson0,
  3. 3. Agenda • Why upgrade? • Refactor our codebase for Puppet 4 • Upgrade our Puppet master(s) and agents to Puppet 4.x • Refactor our codebase to remove Puppet 2- and 3-isms • Tips, tricks, and tools • Enjoying ourselves
  4. 4. Why? • Puppet 4 is old! First released March, 2015 • Puppet 3 is really old! End Of Support on December 31, 2016 • Puppet 4 only modules • Puppet 4 language improvements • Application Orchestration • PE first, FOSS eventually; some free implementations (such as choria) appearing • AIO Puppet and Puppetserver • Better performance, security; same agent/puppetserver between FOSS and PE • Puppet 5 is coming!
  5. 5. Who does this apply to? • Puppet Enterprise users • Puppet Opensource users • Foreman (1.13+) users • Master and Masterless
  6. 6. Blueprint • Start with Puppet 3.x • Read the release notes • Plan the roadmap • Validate / create tests • Refactor until the new version passes all tests • Upgrade/Replace the master(s) • Upgrade the agents • Repeat the Refactor / Upgrade steps until you get to 4.latest
  7. 7. Release Notes • All of them - not just the latest version • Identify potential issues, deprecated features, etc • Determine the minimum version required to upgrade to target version • Stay up to date
  8. 8. Define the Roadmap • Determine the current version • In-place upgrades or new infrastructure? • Identify intermediate version steps • Enable Future Parser [and Strict Variables] before you hit 4.x • PE: Requires intermediate upgrades or fresh installs (check KB) • FOSS: Go straight to 4.latest • Determine how upgrades and interruptions affect ecosystem products – PE Console/puppetboard, SEIMs, monitoring, etc.
  9. 9. FOSS Example Roadmap • 3.6.0 -> 3.8.7 • 3.8.7 w/Future Parser [and Strict Variables] • 3.8.7 -> 4.7.0 • Today’s example roadmap
  10. 10. PE Example Roadmap • 3.7.2 -> 3.8.6 • 3.8.6 w/Future Parser [and Strict Variables] • 3.8.6 -> 2015.3.3 • 2015.3.3 -> 2016.2.1
  11. 11. Validate/Create Tests • Tests assure (mostly) predictable behavior • Determine what kinds of tests you need - unit, acceptance, integration, other? • Good testing setup in puppet-module-skeleton • puppet-retrospec generates naive tests that need tuned • Existing tests must pass before modifying code • Turn on Future Parser [and Strict Variables] only at 3.8.x • Use puppet-lint community plugins, esp for v4 transition • Beyond tests: catalog diffs, personalized tests
  12. 12. Rspec Tests $ cat spec/classes/apache_spec.rb require 'spec_helper' describe 'profile::apache', :type => :class do let :facts do { facts_hash } end context 'with defaults for all parameters' do it { create_class('profile::apache') } it { contain_package('httpd') } it { contain_user("apache") } end end
  13. 13. Rspec Run [rnelson0@build03 profile:production]$ bundle exec rspec spec/classes/apache_spec.rb profile::apache with defaults for all parameters should contain Class[profile::apache] should contain Package[httpd] should contain User[apache] Finished in 7.82 seconds (files took 2.49 seconds to load) 3 examples, 0 failures
  14. 14. Refactor • Create a new branch for the target version, e.g. 3.8.7 • Test against current and target versions, e.g. ~>3.6.0 and ~>3.8.0, with and without Future Parser/Strict Variables • Identify failing tests, refactor to fix • Upgrade modules as early as possible. Be aware of the required Puppet version for a module version, and look out for defunct or migrated modules, such as those transferred to Vox Pupuli • Move forward when tests are green for the next version – previous may be red
  15. 15. Testing with particular Puppet versions $ grep PUPPET Gemfile gem "puppet", ENV['PUPPET_GEM_VERSION'] || '~> 4.0' [rnelson0@build controlrepo]$ export PUPPET_GEM_VERSION='~>3.8.0' [rnelson0@build controlrepo]$ bundle update Installing puppet 3.8.7 (was 4.6.0) [rnelson0@build controlrepo]$ bundle exec puppet --version 3.8.7 [rnelson0@build controlrepo]$ export PUPPET_GEM_VERSION='3.8.1' [rnelson0@build controlrepo]$ bundle update Installing puppet 3.8.1 (was 3.8.7) [rnelson0@build controlrepo]$ bundle exec puppet --version 3.8.1
  16. 16. High level Master(s) upgrade process • Prep for new master/in-place upgrade • Deploy new/upgrade in testing • Revert • Deploy new/upgrade in production • Start with Master of Masters or other “parent” nodes first • Update separate PuppetDB node, puppetdb-termini on masters
  17. 17. Replace the Master • Prepare a new operational environment • Do not serve bad/incorrect catalogs to existing nodes • Deploy a new master on the target puppet version • Bootstrap configuration/code • Test the master against itself, puppet agent -t • Deploy and test canary nodes in the same operational environment
  18. 18. In-place Master upgrade • Snapshot (or equivalent) the master(s) and canary nodes • Restrict access to the master: • Control access with firewall/load balancer • Disable puppet agent on nodes with orchestration • Revoke certificates for non-canary nodes • Revoke the CA, generate a new CA and new agent certs for canary nodes only • Upgrade the master • Test the master then canary nodes with puppet agent -t
  19. 19. Troubleshooting • Collect logs from the master and canaries • Look for changed resources, number of resources in catalog • Revert production environment • Analyze cause(s) • Refactor code and data to address issues • Try again • Learn from failures, prevent them in the future
  20. 20. Upgrade the Agents • Can often skip on PATCH versions and some MINOR versions (see rel notes) • puppetlabs/puppet_agent (requirements) updates agents on next check-in • Orchestration • Replace nodes with new instances running the new agent • By hand
  21. 21. Repeat • Relax, enjoy the success of an upgrade! • Start working on the next version/feature flags • Repeat the Refactor / Upgrade steps
  22. 22. Keeping Up
  23. 23. Keeping Up Refactor to take advantage of Puppet 4 language improvements, new tools (ex: r10k -> PE Code Manager), new file locations, etc. • PE has quarterly upgrades, FOSS more frequent • The less frequently you do something, the more painful it is. “Upgrade early and upgrade often!” • Try not to get more than 2 MINORs behind • Test against puppet version ~>4.0 (latest v4) and run bundle update before manual tests
  24. 24. Puppet 4 Language Improvements • Replace create_resources() with iteration • Replace validate_*() with data types (including a Sensitive type) • There is a validate_legacy() helper function available in puppetlabs/stdlib to assist with replacing validate_*() functions (blog) • Simplified resource wrappers with * and + operators • Improved default attributes are per-expression • New template type EPP is available • Puppet Lookup, Data In Modules, and other hiera improvements • Use $facts[] instead of global variables to tidy up the namespace and remove ambiguity
  25. 25. Tips & Tricks – Puppet Enterprise • PE includes support, use it for planning/errors • Puppet Enterprise Upgrade Service to engage Pro Services • PE Classifier changes over time. Review Preconfigured Node Groups documentation • pe_puppetserver_gem is out, puppetserver_gem is in • Do not use PE’s bundled Ruby for other Ruby tasks, conflicts between bundled/downloaded gems. Recommend rbenv/rvm or SCL-equiv instead • Do not ever do this on your master. EVER!
  26. 26. Tips & Tricks - Strings Understand how string conversion works in puppet, hiera, rspec-puppet, and how it has changed: • rspec-puppet: 'undef' represents an undefined value • Puppet DSL: it is the string undef! Try :undef, without quotes, instead • If you have a file resource with a title or path of ${undefvar}/${populatedvar}, rspec will start failing because file { 'undef/etc/app.conf' :} is not valid • Similar issue with 'true' vs true and 'false' vs false • Other common issues: input from hiera/ENC, quoted numbers as strings, stringify vs structured facts, unquoted strings in case selectors, etc • May require acceptance tests/canary nodes to become apparent
  27. 27. Tips & Tricks - Hiera • Hiera eyaml gem is lost during the upgrade to the 4.x puppetserver • Enable the yaml backend and ensure that the master does not rely on eyaml data • Run the agent on the master to redeploy the gem (with puppet/hiera or similar) before agents check in • %{}: used to prevent variable interpolation, as in %%{}{environment} to generate the string %{environment}. In 3.x and in 4.5 resolves to an empty string, in 4.0-4.4 it returned the scope, giving strings like %<#Hiera:7329A802#>{environment}. Use %{::} instead, as in %%{::}{environment}. Affects PE < 2016.2.0 • datadir: some versions expect :: prepends to variables and others do not. Change %{environment} to %{::environment}. Likely PE < 2016.2.0 as well
  28. 28. Tips & Tricks - Other • Review modules and their supported versions. May be incorrect or weak assumptions (>= 3 but should also include < 4 – check tests) • Upgrades across major versions mean additional troubleshooting • Upgrade early – but with caveats • Many tools to assist with automating version upgrades in your Puppetfile • ERB scope: prepend most variables with @ (<%= var %> to <%= @var %>) • Script to detect usage of hardcoded /etc/puppet paths, no longer correct in v4 • External fact weighting bug: FACT-1413 • Minimize coupled/entangled changes • Ask for help! Colleagues, social media, etc.
  29. 29. Tools • Puppet Community Slack / IRC and Mailing Lists • puppet-ghostbuster helps you find "dead code" that you may want to prune before you start on your refactoring journey. • rspec-puppet, puppetlabs_spec_helper, and puppet-lint are improving their Puppet 4 support • A number of catalog diff tools exist (diff generators and a viewer) to inspect the actual catalog differences from active nodes across different versions of Puppet.
  30. 30. Links Additional information on Puppet 4 and Migrations • Official Puppet Upgrade Docs • Whirlwind Tour of Puppet 4 by R.I. Pienaar • The Power of Puppet 4 by Martin Alfke • Puppet - our journey from Puppet 3.8 to Puppet 4 by Jonas Genannt
  31. 31. Summary • Plan the upgrade roadmap • Have working tests before upgrading • Step through the new versions / feature flags • Refactor code to take advantage of the language and tool improvements • Keep mowing • Enjoy the journey!