h1ghlevelb1ts

So finally I got around setting up travis to automatically post this blog upon pushes to master. It was pretty straight forward. Travis picks up a file called .travis.yml where the build configuration is placed. It ended up looking like this:

language: ruby

install: bundle install
script:  "./publish_from_travis.sh"

# this is the encrypted api key from github setting 
# the GH_AUTH env variable used in the install script
env:
  global:
    secure: hrfBYK9YXs0rJJvr3zbIFFt7E11KdbtTzbSYgvULEhVgRwXscKRj.....

# build only master - don't want to publish wip
branches:
  only:
    - master

First the language of the build is stated.

language: ruby

Travis comes with two steps: install and script where the latter means test tour stuff.

install: bundle install
script:  "./publish_from_travis.sh"

The normal build process is more about automated testing than automated publishing. Here I use the install stuff for the reasonable thing to do - installing them gems. Than in the script phase a bash script is called. This is circa the same script as we have been using to publish from our local machines but with some small changes about how the gh-pages branch is cloned and updated. Firstly https is used. Since this is a public repo cloning is trivial. For pushing there needs to be some credentials though. Here is the publish script:

#! /usr/bin/env bash

git config --global user.email "highlevelbits@eldfluga.se"
git config --global user.name "high level bits automator"

git clone https://github.com/highlevelbits/blog.git --branch gh-pages output
rm -rf output/*
nanoc
cd output
echo highlevelbits.com > CNAME
git add .
git commit -am "high level bits automatic deploy"
git push --force --quiet "https://${GH_AUTH}@github.com/highlevelbits/blog.git" gh-pages> /dev/null 2>&1

Note the environment variable use in the push command. This is a reference to an encrypted variable stored in the end->global->secure key:

# this is the encrypted api key from github setting 
# the GH_AUTH env variable used in the install script
env:
  global:
    secure: hrfBYK9YXs0rJJvr3zbIFFt7E11KdbtTzbSYgvULEhVgRwXscKRj....

This field is generated with the travis command line tool. Install it with:

> gem install travis

and use it like so

> echo GH_AUTH=<github api key> | travis encrypt --add

the -add flag adds it automatically to the .travis.yml in the current directory. Handy! Now it is encrypted so that only travis can decrypt.

Finally we tell travis to only build master so we can keep branches for work in progress without publishing them.

# build only master - don't want to publish wip
branches:
  only:
    - master

All the files used for publishing the blog are available for review in the repository.

I had some excellent help from Gergely Nemeths post about this (just translated the node stuff into ruby) and also from the excellent travis docs.

So what will this give us? Hopefully more shorter posts since it now will be possible to publish directly with a push inside github.