New blog post: upcoming CI env changes

blog/_posts/2012-08-25-ubuntu-1204-migration.md

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+---
+title: Upcoming CI Environment Updates
+layout: post
+created_at: Sat Aug 25 12:00:00 CDT 2012
+permalink: blog/august-2012-upcoming-ci-environment-updates
+author: Michael Klishin
+twitter: michaelklishin
+---
+
+An important part of Travis CI is our [CI environment](http://about.travis-ci.org/docs/user/ci-environment/): all the runtimes, tools, libraries and system configuration that
+projects rely on to run their test suites. While considered to be the most mature part of Travis CI (we are at v5.1 at the moment),
+it still moves fast. Today we want to give you a heads-up on important upcoming changes:
+
+ * CI username change
+ * Disabling some services (e.g. MongoDB, Riak, RabbitMQ) on boot
+ * Migration to Ubuntu 12.04
+ * Migration to 64 bit VMs
+
+
+## CI Username Change
+
+Starting on August 25th, we will deploy new VM images that change CI username from `vagrant` to `travis`. If your project depends on
+
+ * The exact username
+ * `$HOME` pointing to `/home/vagrant`
+
+then you need to update your `.travis.yml` and/or build system to use `USER` and `HOME` instead. Depending on exact values of those variables
+is usually not necessary: the best way to detect that you are running in the Travis CI environment is by checking if `CI` and `TRAVIS` env varibales
+are set. If you feel adventurous, feel free to use [`HAS_OSH_K_SEAL_OF_APPROVAL`](https://github.com/travis-ci/travis-cookbooks/blob/master/ci_environment/travis_build_environment/files/default/vagrant/travis_environment.sh#L8-9) instead (nevermind, this is our internal joke; and yes, [Josh K is a real person](https://twitter.com/j2h)).
+
+
+## Disabling Most Services on Boot
+
+Currently when VMs we use for CI environment boot, a number of services is started:
+
+ * MySQL
+ * PostgreSQL
+ * RabbitMQ
+ * MongoDB
+ * Redis
+ * Riak
+ * CouchDB
+
+and so on. In total, they consume a non-trivial amount of RAM. This limits both the amount of RAM available to your test suites and our ability to move
+some parts of the environment (for example, MySQL and PostgreSQL data directories) to RAM-based file system mounts to speed up test suites that
+are very heavy on I/O and in particular random access I/O (think Ruby on Rails or Django). Tuning configuration of services to consume less RAM
+is possible but it is very hard to pick good defaults for all of them.
+
+In addition, most projects don't use those services. As such, we will make several of them to not start on boot, leaving only MySQL and PostgreSQL running.
+Note that we already do this for some services (for example, Cassandra, Neo4J, ElasticSearch).
+
+If your project needs, say, MongoDB running, you will have to add the following to your `.travis.yml`:
+
+    before_install:
+      - sudo service mongodb start
+
+This should exit successfully regardless of whether MongoDB is already running. If this is not the case, you can use
+
+    before_install:
+      - sudo service mongodb start; /bin/true
+
+to make sure the `before_install` step always exists cleanly and does not fail your build.
+
+Because some services have irregular names, we will soon deploy a feature that will let you do this more elegantly and let Travis builders figure out what service
+to start:
+
+    services:
+      - riak     # will start riak
+      - rabbitmq # will start rabbitmq-server
+      - memcache # will start memcached
+
+The change will go into effect on August 31st, 2012. We encourage Travis CI users to make changes to their `.travis.yml` files to be forward-compatible.
+
+
+## Distribution Versions: A Brief History Lesson
+
+When we first started using virtual machines for Travis CI (around June 2011) we decided to use Ubuntu 10.04. This worked perfectly, but by the fall of 2011 10.04 started showing its age. Our users kept asking for more recent versions of certain tools and libraries which were challenging to provide without building and maintaining a myriad of Debian packages. So in November 2011 we migrated all VMs to Ubuntu 11.04 which solved the problem. In early April 2012 we [migrated to 11.10](http://about.travis-ci.org/blog/upcoming_ubuntu_11_10_migration/).
+
+Now it is August 2012 and the time to move on to 12.04 is drawing close. We want to explain briefly how Travis CI will migrate to it, why we are doing it and what may
+change for your project.
+
+
+## Why Migrate?
+
+With Ubuntu 12.04, we will be able to provide more up-to-date versions of tools and services in our CI environment, including:
+
+ * MySQL 5.5
+ * CouchDB 1.2
+ * Updated Git
+
+and many others. In addition, we hope to be able to provision Python 3.3 preview releases (there are 12.04 packages we can use).
+
+
+## Staying One Step Behind, Intentionally
+
+Our users are mostly software developers and they tend to like to staying up-to-date with tools, services, libraries and so on. However, production environments are rarely on the bleeding edge. So for CI in general, and Travis CI in particular, it is important to maintain a balance: not too old, but not too new either. This is why Travis CI is intentionally several months behind Ubuntu releases. It gives developers several months to catch up with recent changes, fix issues and push out new releases.
+
+
+## Notable Changes in 12.04
+
+12.04 is a significantly smaller change that 11.10 has been: no breaking changes to fundamental libraries like OpenSSL, no [major or minor] GCC version changes,
+et cetera.
+
+### MySQL Server
+
+12.04 provides MySQL Server 5.5. Most projects should keep working without any changes.
+
+
+### System Perl
+
+System Perl version changes to 5.14. This won't matter for Perl projects on Travis CI (we use a separate set of Perls provisioned with [Perlbrew](http://perlbrew.pl/)) but
+projects in other languages that use Perl as part of their build system may be affected.
+
+
+### System Erlang/OTP
+
+System Erlang/OTP version changes to R14B04. This won't matter for Erlang projects on Travis CI (we use a separate set of OTP builds provisioned with [kerl](https://github.com/spawngrid/kerl)) but
+projects in other languages that may rely on Erlang as part of their build system may be affected.
+
+
+### Bison 2.5
+
+Projects that use Bison may need to check for 2.5 compatibility.
+
+
+## The Road To 12.04
+
+Travis CI environment will transition to 12.04 in the first week of September, 2012.
+
+
+## Migrating CI Environment to 64 bit
+
+Currently Travis CI environment is 32 bit. This works fine for most cases but has a few downsides:
+
+ * The majority of developers and projects target 64 bit first because this is their deployment environment of choice.
+ * Some runtimes are primarily used in 64 bit environments and their 32 bit counterparts have stability issues that are outside of our control.
+
+Because we already work towards freeing more RAM for project test suites to use, we decided it is a good time to also move to 64 bit.
+The exact migration date is not yet decided, but most likely this will happen in September or early October 2012.
+
+
+## Getting Help
+
+If you have questions, please ask them on our [mailing list](https://groups.google.com/forum/?fromgroups#!forum/travis-ci) or in
+`#travis` on irc.freenode.net.
+
+
+Happy testing!
+
+
+The Travis CI Team