Git Deployment
New
Subcommands introduced in 0.12.0
git:allow-host <host> # Adds a host to known_hosts
git:sync [--build] <app> <repository> [<git-ref>] # Clone or fetch an app from remote git repo
git:initialize <app> # Initialize a git repository for an app
git:public-key # Outputs the dokku public deploy key
git:report [<app>] [<flag>] # Displays a git report for one or more apps
git:set <app> <key> (<value>) # Set or clear a git property for an app
Git-based deployment has been the traditional method of deploying applications in Dokku. As of v0.12.0, Dokku introduces a few ways to customize the experience of deploying via git push. A Git-based deployment currently supports building applications via:
Usage
Warning
Pushing from a shallow clone is not currently supported and may have undefined behavior. Please unshallow your local repository before pushing to a Dokku app to avoid potential errors in the deployment process.
Initializing an application
When an application is created via git push, Dokku will create the proper pre-receive hook in order to execute the build pipeline. In certain cases - such as when fronting deploys with the git-http-backend - this may not be correctly created. As an alternative, the git:initialize command can be used to trigger this creation:
In order for the above command to succeed, the application must already exist.
Warning
If the pre-receive hook was customized in any way, this will overwrite that hook with the current defaults for Dokku.
Changing the deploy branch
By default, Dokku will deploy code pushed to the master branch. In order to quickly deploy a different local branch, the following Git command can be used:
# on the local machine
# where `SOME_BRANCH_NAME` is the name of the branch
git push dokku SOME_BRANCH_NAME:master
In 0.12.0, the correct way to change the deploy branch is to use the git:set Dokku command.
# on the Dokku host
# override for all applications
dokku git:set --global deploy-branch SOME_BRANCH_NAME
# override for a specific app
# where `SOME_BRANCH_NAME` is the name of the branch
dokku git:set node-js-app deploy-branch SOME_BRANCH_NAME
Pushing multiple branches can also be supported by creating a receive-branch plugin trigger in a custom plugin.
Configuring the GIT_REV environment variable
New
Introduced in 0.12.0
Application deployments will include a special GIT_REV environment variable containing the current deployment sha being deployed. For rebuilds, this SHA will remain the same.
To configure the name of the GIT_REV environment variable, run the git:set command as follows:
# on the Dokku host
# override for a specific app
dokku git:set node-js-app rev-env-var DOKKU_GIT_REV
This behavior can be disabled entirely on a per-app basis by setting the rev-env-var value to an empty string:
Keeping the .git directory
By default, Dokku will remove the contents of the .git before triggering a build for a given app. This is generally a safe default as shipping the entire source code history of your app in the deployed image artifact is unnecessary as it increases bloat and potentially can leak information if there are any security issues with your app code.
To enable the .git directory, run the git:set command as follows:
# on the Dokku host
# keep the .git directory during builds
dokku git:set node-js-app keep-git-dir true
The default behavior is to delete this directory and it's contents. To revert to the default behavior, the keep-git-dir value can be set to either an empty string or false.
# on the Dokku host
# delete the .git directory during builds (default)
dokku git:set node-js-app keep-git-dir false
# delete the .git directory during builds (default)
dokku git:set node-js-app keep-git-dir ""
Please keep in mind that setting keep-git-dir to true may result in unstaged changes shown within the built container due to the build process generating application changes within the built app directory.
Initializing an app repository from a remote repository
Info
The application must exist before the repository can be initialized
A Dokku app repository can be initialized or updated from a remote git repository via the git:sync command. This command will either clone or fetch updates from a remote repository and has undefined behavior if the history cannot be fast-fowarded to the referenced repository reference. Any repository that can be cloned by the dokku user can be specified.
The git:sync command optionally takes an optional third parameter containing a git reference, which may be a branch, tag, or specific commit.
# specify a branch
dokku git:sync node-js-app https://github.com/heroku/node-js-getting-started.git main
# specify a tag
dokku git:sync node-js-app https://github.com/heroku/node-js-getting-started.git 1
# specify a commit
dokku git:sync node-js-app https://github.com/heroku/node-js-getting-started.git 97e6c72491c7531507bfc5413903e0e00e31e1b0
By default, this command does not trigger an application build. To do so during a git:sync, specify the --build flag.
Allowing remote repository hosts
By default, the Dokku host may not have access to a server containing the remote repository. This can be initialized via the git:allow-host command.
Note that this command is currently not idempotent and may add duplicate entries to the ~dokku/.ssh/known_hosts file.
Verifying the cloning public key
In order to clone a remote repository, the remote server should have the Dokku host's public key configured. This plugin does not currently create this key, but if there is one available, it can be shown via the git:public-key command.