Deploying to Dokku
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:
Each service 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.
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.
Some tools may not support the short-upstream syntax referenced above, and you may need to prefix
the upstream with the scheme
ssh:// like so:
Please see the Git documentation for more details.
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 ... =====> Application deployed: http://ruby-rails-sample.dokku.me
When the deploy finishes, the application's URL will be shown as seen above.
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
An alternative is to use the
DOKKU_DEPLOY_BRANCH application config value to specify a branch that should be deployed. The implicit default is master, and this can be modified both at the app and global level:
You can also support pushing multiple branches using the receive-branch plugin trigger in a custom plugin.
If you only want to rebuild and tag a container, you can skip the deployment phase by setting
true by running:
Re-Deploying / restarting
If you need to re-deploy (or restart) your app:
See the process scaling documentation for more information.
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.
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:
You can also specify fully qualified names, say
This is in particular useful, then you want to deploy to root domain, as
... 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
exited, as well as all
dangling images. Previous versions would remove
exited containers, regardless of their label.
Adding deploy users
See the user management documentation.
See the nginx documentation.
See the dockerfile documentation.
Specifying a custom buildpack
See the buildpack documentation.
See the image tagging documentation.
Removing a deployed app
See the application management documentation.
Renaming a deployed app
See the application management documentation.
Zero downtime deploy
See the zero-downtime deploy documentation.