Deploying to Dokku
Deploy tutorial
Once Dokku has been configured with at least one user, applications can be deployed via a git push command. To quickly see Dokku deployment in action, you can use the Heroku Ruby on Rails example app.
Create the app
Create the application on the Dokku host. You will need to ssh onto the host to run this command.
Create the backing services
When you create a new app, Dokku by default does not provide any datastores such as MySQL or PostgreSQL. You will need to install plugins to handle that, but fortunately Dokku has official plugins for common datastores. Our sample app requires a PostgreSQL service:
# on your dokku host
# install the postgres plugin
# plugin installation requires root, hence the user change
sudo dokku plugin:install https://github.com/dokku/dokku-postgres.git
# create a postgres service with the name rails-database
dokku postgres:create rails-database
Info
Each services may take a few moments to create.
Linking backing services to applications
Once the service creation is complete, set the POSTGRES_URL environment variable by linking the service.
# on your dokku host
# each official datastore offers a `link` method to link a service to any application
dokku postgres:link rails-database ruby-rails-sample
Info
You can link a single service to multiple applications or use one service per application.
Deploy the app
Now you can deploy the ruby-rails-sample app to your Dokku server. All you have to do is add a remote to name the app. Applications are created on-the-fly on the Dokku server.
# from your local machine
git remote add dokku dokku@dokku.me:ruby-rails-sample
git push dokku master
You should see output similar to the following:
Counting objects: 231, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (162/162), done.
Writing objects: 100% (231/231), 36.96 KiB | 0 bytes/s, done.
Total 231 (delta 93), reused 147 (delta 53)
-----> Cleaning up...
-----> Building ruby-rails-sample from herokuish...
-----> Adding BUILD_ENV to build environment...
-----> Ruby app detected
-----> Compiling Ruby/Rails
-----> Using Ruby version: ruby-2.2.1
-----> Installing dependencies using 1.9.7
Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin -j4 --deployment
Fetching gem metadata from https://rubygems.org/...........
Fetching version metadata from https://rubygems.org/...
Fetching dependency metadata from https://rubygems.org/..
Using rake 10.4.2
...
When the deploy finishes, the application's URL will be shown.
Dokku supports deploying applications via Heroku buildpacks with Herokuish or using a project's dockerfile.
Removing a deployed app
You can also remove an application from your Dokku installation. This will unlink all linked services and destroy any config related to the application. Note that linked services will retain their data for later use (or removal).
This will prompt you to verify the application's name before destroying it. You may also use the --force flag to circumvent this verification process:
Renaming a deployed app
New
Introduced in 0.4.7
You can rename a deployed app using the apps:rename CLI tool:
This will copy all of your app's contents into a new app directory with the name of your choice, delete your old app, then rebuild the new version of the app and deploy it. All of your config variables, including database urls, will be preserved.
Deploying non-master branch
Dokku only supports deploying from its master branch, so if you'd like to deploy a different local branch use: git push dokku <local branch>:master
You can also support pushing multiple branches using the receive-branch plugin trigger in a custom plugin.
Skipping deployment
If you only want to rebuild and tag a container, you can skip the deployment phase by setting $DOKKU_SKIP_DEPLOY to true by running:
Deploying with private git submodules
Dokku uses git locally (i.e. not a docker image) to build its own copy of your app repo, including submodules. This is done as the dokku user. Therefore, in order to deploy private git submodules, you'll need to drop your deploy key in /home/dokku/.ssh/ and potentially add github.com (or your VCS host key) into /home/dokku/.ssh/known_hosts. The following test should help confirm you've done it correctly.
# on your dokku host
su - dokku
ssh-keyscan -t rsa github.com >> ~/.ssh/known_hosts
ssh -T git@github.com
Note that if the buildpack or dockerfile build process require ssh key access for other reasons, the above may not always apply.
Deploying to subdomains
The name of remote repository is used as the name of application to be deployed, as for example above:
$ git remote add dokku dokku@dokku.me:ruby-rails-sample
$ git push dokku master
Is deployed to,
remote: -----> Application deployed:
remote: http://ruby-rails-sample.dokku.me
You can also specify fully qualified names, say app.dokku.me, as
$ git remote add dokku dokku@dokku.me:app.dokku.me
$ git push dokku master
So, after deployment the application will be available at,
remote: -----> Application deployed:
remote: http://app.dokku.me
This is in particular useful, then you want to deploy to root domain, as
$ git remote add dokku dokku@dokku.me:dokku.me
$ git push dokku master
... deployment ...
remote: -----> Application deployed:
remote: http://dokku.me
Dokku/Docker Container Management Compatibility
Dokku is, at its core, a docker container manager. Thus, it does not necessarily play well with other out-of-band processes interacting with the docker daemon. One thing to note as in issue #1220, dokku executes a cleanup function prior to every deployment.
As of 0.5.x, this function removes all containers with the label dokku where the status is either dead or exited, as well as all dangling images. Previous versions would remove dead or exited containers, regardless of their label.
Adding deploy users
See the user management documentation.
Default vhost
See the nginx documentation.
Dockerfile deployment
See the dockerfile documentation.
Specifying a custom buildpack
See the buildpack documentation.
Image tagging
See the image tagging documentation.
Zero downtime deploy
See the zero-downtime deploy documentation.