Travis-CI

For certain websites it can be interesting to use Travis-CI to automatically deploy the latest version of a website from a github repository. This is particularly useful when coupled with the GitHub Pages deployment method which is what we're going to cover in this guide. But you can easily adjust it to any other method.

This assumes you already signed up for Travis-CI. If you have not, just head to travis-ci.org and sign up with your GitHub account.

This guide is also available as a 7 minute screencast.

Travis Config

Once you have signed up for Travis-CI you need to add a .travis.yml config file into your repository. You can copy paste this over:

language: python
python: 2.7
install: "pip install Lektor"
script: "lektor build"
deploy:
  provider: script
  script: "lektor deploy ghpages"

Because Travis already comes with all dependencies we need other than Lektor itself we just need to pip install Lektor and we're ready to go. For the build step we invoke lektor build, and for the deploy step we invoke lektor deploy ghpages to ship it to the ghpages server. We still need to configure that.

Project Server Config

For the above example the best way to configure the server for the deployment in the project file would be to use ghpages+https like this:

[servers.ghpages]
target = ghpages+https://username/repository

You need to add this to your .lektorproject file.

Whenever Travis builds it will automatically throw the end result into the gh-pages branch and the website updates. We do however still need to configure the access credentials. We will get to that.

Enabling Travis

So now that we have all that configured we need to tell travis to build the repository. For that just head to your Travis-CI Profile and enable the repository. If it does not show up yet, you can force a sync with the click of a button.

Access Credentials

So how do you safely provide your credentials? Lektor accepts username and password for the ghpages+https transport via the LEKTOR_DEPLOY_USERNAME and LEKTOR_DEPLOY_PASSWORD environment variables. These can be set in the Travis-CI settings of your repository on travis-ci.org in secret so they are not stored anywhere else and will not show up in the build output. However one thing you need to be careful with is that they still give access to your entire account!

To solve this problem we recommend two things:

  1. Create a personal access token and use that instead. Just provide the token instead of your password on sign-in. This makes it easily possible to just revoke that token if something goes wrong. Note that you only need the repo scope for this to work. This also works if you have 2FA activated on an account.
  2. Create a deployment (machine) user. This allows you to use a user that is exclusively used for just the purpose of updating the website.

Once you have done that travis will start deploying the website on every commit.

When copy/pasting username and password into travis please ensure that you do not copy any leading or trailing whitespace with it. This will not just break the build but also reveal the password in the process. For more information see travis-ci#4139.

Committer Information

By default the commits to the gh-pages branch will be authored by a user named “Lektor Bot”. If you want to override this you can export the GIT_COMMITTER_NAME and GIT_COMMITTER_EMAIL environment variables and set them to something else. This is best done in the travis settings.

Private Repositories

If you are using private repositories you will need the commercial version of travis. It has the advantage that you can also set up SSH keys on there which means that authentication becomes easier. For more information see Private Dependencies in the Travis CI documentation.

Speeding up Builds with Caching

In the default setting Travis will have to rebuild everything because between builds it does not cache the build results. You can change this by enabling caching. Adjust your .travis.yml file to look like this:

language: python
python: 2.7
cache:
  directories:
    - $HOME/.cache/pip
    - $HOME/.cache/lektor/builds
install: "pip install Lektor"
script: "lektor build"
deploy:
  provider: script
  script: "lektor deploy ghpages"

Restricting Branches

If you plan on having different branches and contributors you should disable the deployment to the master branch only. You can do this with the following config:

language: python
python: 2.7
cache:
  directories:
    - $HOME/.cache/pip
    - $HOME/.cache/lektor/builds
install: "pip install Lektor"
script: "lektor build"
deploy:
  provider: script
  script: "lektor deploy ghpages"
  on:
    branch: master

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