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Using version control and deploying

This page assumes that your project has already been set up for version control. If you see a Configure Git button instead of the choices described on this page, you need to first set up Git for your project.

Git integration for version control

Looker uses Git to record changes and manage file versions. Each LookML project corresponds with a Git repository, and each developer branch correlates to a Git branch. Git repositories are often called repos.

Looker generally uses GitHub for LookML source-file management. However, Looker can be configured to also work with other Git providers such as GitLab, Bitbucket, or any Git server that can use an SSH key for authentication.


Starting in August 2021, GitHub no longer accepts account passwords for authenticating Git operations on github.com. See GitHub’s blog post for more information. To connect a Looker project to GitHub using HTTPS, use the developer settings in GitHub to create a personal access token. For existing Looker projects that connect to GitHub using HTTPS, reset your Git connection using a personal access token from GitHub.

A Looker project uses only one account with your Git provider for all Git interactions (see the Integrating Looker with Git documentation page for information on setting up Git). For each Looker project, all the development from all your Looker developers goes through this one Git account. This means that Looker developers do not need to have their own accounts with your Git provider, unless your Looker instance is set up with one of the additional Git integration options. In this case, a Looker developer would need a Git account to open external links to your Git provider or to create a pull request.

Working with Git branches

One of the main benefits of Git is that a Looker developer can work in a branch, an isolated version of a file repository. You can develop and test without affecting other users. As a developer in Looker, you are using a Git branch whenever you are in Development Mode.

Another major feature of Git is the ease of collaborating with other developers that it provides. You can create a branch and (if desired) make changes, and then other developers can switch to that branch to review or make changes to the branch. If another developer has committed changes to the branch, Looker displays the Pull Remote Changes button. You should pull those committed changes to the branch before making additional changes.

You can also delete a branch other than the master branch, your current branch, or a developer’s personal branch.

Personal branches

The first time you go into Development Mode, Looker automatically creates your personal Git branch. Your personal branch starts with dev- and includes your name:

Your personal branch is specific to you, and it cannot be deleted. Your personal branch is read-only to all other developers. If you are collaborating with other developers on a project, you may want to create a new branch so that others can switch to that branch and contribute changes as well.

TIP: You can’t make changes to another developer’s personal branch. To build on work in somebody else’s personal branch, create a new branch starting from their branch.

Creating a new Git branch

If you are working on a simple fix and not collaborating with other developers, your personal branch is usually a good place to work. You can use your personal branch to make quick updates, and then commit the changes and push them to production.

However, you may also want to create new Git branches in addition to your personal branch. A new Git branch makes sense in these situations:

Before creating a new branch:

To create a new Git branch:

  1. Verify that you have Development Mode turned on.
  2. Navigate to your project files in the Develop menu. On Looker version 21.12 or later, if your admin has enabled the Enhanced Navigation Labs feature, use the Develop option in the new enhanced left navigation panel to navigate to your project files.

  1. Click the Git icon in the left-hand icon menu to open the Git Actions panel.
  2. Click to open the Git branch drop-down menu.
  3. Select New Branch.
  4. In the New Branch window, enter a name for your branch. Note that there are limitations for Git branch names; for naming requirements, see Rules for naming a Git branch on this page.
  5. Click the Create From drop-down menu and select an existing branch to use as the starting point for your new branch.
  6. Click Create to create your branch.

Alternatively, you can create Git branches from the Branch Management tab of the Project Settings page.

Rules for naming a Git branch

Looker uses the branch-naming-convention requirements specified by Git.

Git branch names must not:

In addition, the branch name can only contain an asterisk (*) if the asterisk represents an entire path component (for example, foo/* or bar/*/baz), in which case it is interpreted as a wildcard and not as part of the actual branch name.

Switching to another Git branch

If you have a merge conflict on your current branch, you must resolve the conflict before you can switch to a different branch.

Also, if you have uncommitted changes on your current branch, you cannot switch to an existing branch until you commit the changes on your current branch.

To switch to a different Git branch:

  1. In the project, navigate to the Git Actions panel by clicking the Git icon in the left-hand icon menu.
  2. In the Git Actions panel, click on the Git branch drop-down menu by your current Git branch name.
  3. Select the branch you want to switch to by selecting it in the menu, or by typing the branch name into the search box. Branch name search is case-insensitive. For example, you can search for “DEV” and see all branches with names that include “dev”, “DEV”, “Dev”, and so on.

Managing Git branches

The Branch Management tab of the Project Settings page shows a table of all the Git branches for the Looker project. To open the Branch Management tab, navigate to the Project Settings page by clicking the Settings icon from the left-hand icon menu and selecting the Branch Management tab.

On the Branch Management tab, you can:

  1. Create a new branch by clicking the New Branch button. See the Creating a new Git branch section on this page for more information.
  2. Search for branch names in the Search Bar.
  3. Refresh the table by clicking the Refresh button.
  4. Sort the table by clicking a column name.

The table includes the following information:

Deleting Git branches

From the Branch Management tab, you can delete branches that have a Delete button in the table. You cannot delete the following branches:

In the table, these branches don’t have a Delete button. Instead, the Action column of the table shows the reason that the branch can’t be deleted.

You cannot restore a branch once it’s been deleted. When you delete a branch, Looker removes both your local version of the branch and the remote version of the branch.

However, if the branch was created by another Looker developer, or if other developers have checked out the branch, those developers will still have their local version of the branch. If a Looker developer makes commits to their local version of the branch and pushes it to production, you will once again see a remote version of the branch. This can be handy if you do want to restore the branch. Otherwise, when you delete a branch, all other Looker developers should delete the same branch to ensure that it can’t be accidentally resurfaced by someone pushing it to remote.

To delete one or several Git branches from your project, navigate to the Project Settings page by clicking the Settings icon from the left-hand icon menu and selecting the Branch Management tab. In the Branch Management tab, you can delete branches in two ways:

  1. Delete multiple branches by selecting the branch checkboxes and clicking Delete Selected Branches.
  2. Delete a single branch by clicking Delete next to the branch name.

Executing Git commands in Looker

Looker has a built-in interface that integrates with your Git service. In the LookML IDE, you’ll see a button in the upper right for Git:

The Git button shows different options depending on where you are in the process of making changes and deploying to production. In general, the option shown on the button is the best guide for your next action.

If your developer branch is in sync with the production branch, you will see the Up to Date message:

Once your project is configured for Git, the IDE will show the Git Actions panel with additional Git commands:

The commands available on the Git Actions panel depend on where you are in the process of making changes and deploying to production.

Getting your changes to production

With the default Looker Git integration, Looker prompts developers through the following Git workflow:

This means that, with the default Git integration, all developers merge their changes into a branch called master, and the latest commit on the master branch is what is used for the production environment of Looker.

For advanced Git implementations, you can customize this workflow:

If you see a Configure Git button instead of the choices described in this section, you need to first set up Git for your project.

Viewing uncommitted changes

The LookML IDE has several indicators that are displayed when you are in Development Mode and have uncommitted changes, as described in the Marking additions, changes, and deletions section of the Editing and validating LookML documentation page.

You can get a difference summary for all files by using the View Uncommitted Changes option from the Git Actions panel:

In the Uncommitted Changes to Project window, you can see a summary of all the uncommitted, saved changes in all the project’s files. For each change, Looker shows the following:

You can also get a difference summary for a single file by selecting the View Changes option from the file’s menu:

Committing changes

After you have made and saved any changes to your LookML project, the IDE may require you to validate your LookML:

Whether this is required depends on your project’s setting for code quality. For more information on the Content Validator, see the Validating your LookML documentation page.

If another developer has made changes to the production branch since you last updated your local branch, Looker requires you to pull those updates from the production branch:

If your project is enabled for advanced deploy mode, this button will specify the name of your production branch.

Once you save your changes (and fix any LookML warnings or errors, if required) and pull from production (if required), the Git button displays the following message:

If desired, you can first review your uncommitted changes before committing.

When you are ready to commit the changes, use the Commit Changes & Push button to commit these changes to your current branch. The following window appears, listing the files that have been added, changed, or deleted.

Enter a message that briefly describes your changes, and uncheck any files you don’t want included in the sync. Then click Commit to commit the changes.

Checking for unbuilt PDTs

Running data tests

Your project may include data tests to verify the logic of your LookML model. See the test parameter documentation page for information on setting up data tests in your project.

You must be in Development Mode to run data tests. Once you’re in Development Mode, there are several ways to initiate data tests for a project:

  1. If your project settings are configured to require data tests to pass before deploying your files to production, the IDE will present the Run Tests button after you commit changes to the project. This will run all the tests for your project, no matter which file defines the test. You must pass the data tests before you can deploy your changes to production.
  2. Click the Run Data Tests button in the Code Validation panel. This will run all data tests in your project, no matter which file defines the test.
  3. Select the Run LookML Tests option from the file’s menu. This will run only the tests defined in the current file.

Once you run the data tests, the Code Validation panel will show you the progress and results:

Deploying to production

Once you have committed changes to your branch, the Looker IDE will prompt you to merge your changes to the production branch. The type of prompt you’ll see in the IDE will depend on your project’s configuration:

Advanced deploy mode

With the default Looker Git integration, Looker developers commit their changes to their development branch, then merge their development branch into the production branch. Then, when you deploy to the Looker environment, Looker uses the latest commit on the production branch. (See the Getting your changes to production section on this page for the default Git workflow and other options for advanced Git implementations.)

For cases where you don’t want the to always use the latest commit on the production branch for your Looker environment, a developer with deploy permission can use advanced deploy mode to specify the exact commit to be used for your Looker environment. This is useful in multi-environment developer workflows, where each environment points to a different version of a codebase. It also gives one or several developers or administrators greater control over the changes that are deployed to production.

When advanced deploy mode is enabled, the Looker IDE does not prompt developers to deploy their changes to production. Instead, the IDE prompts developers to merge their changes into the production branch. From there, changes can be deployed only in the following ways:

See the Advanced deploy mode documentation page for details.

Checking the impact of your changes

After making your changes available to the organization, you can use content validation to make sure you have not invalidated any dashboards or saved Looks. You’ll have the opportunity to fix them if you have.

Handling typical issues

While working on your model, you may need to:

Some changes, such as changing the name of a field, can affect existing dashboards and Looks. As mentioned earlier, after making your changes available to the organization, you can use content validation to check your content and fix any issues.

Reverting uncommitted changes

When working on your personal development branch, you can revert uncommitted changes that you have saved if you do not want to deploy them. You can revert all the uncommitted changes for all files in the project or just the changes in a single file.

To revert uncommitted changes for all files:

  1. Click the Revert to… option in the Git Actions panel.
  2. Select a revert option:
    • To revert only uncommitted changes, select Revert uncommitted changes. You can also click the View changes link to view the changes that would be reverted.
    • To revert all changes, including uncommitted and committed changes, select Revert to Production
  3. To complete the revert, click Confirm.

To revert any additions or deletions in the contents of a single file, select the Revert Changes option from the file’s menu:

When you rename a file, you are essentially deleting the original file and creating a new file with a new name. Because this involves more than one file, you can’t use the Revert File option to undo the renaming of a file. If you want to undo a file rename, use the Revert to… option from the Git Actions panel.

Also, if you have deleted a file, the file is no longer displayed in the IDE file browser. If you want to revert the deletion of a file, use the Revert to… option from the Git Actions panel.

Resolving merge conflicts

Typically, Git can automatically merge your new changes with the production version of your LookML files. A merge conflict occurs when Git has trouble determining which changes to keep. This usually occurs when another developer has made changes since you last pulled and you have made changes in the same area. If you have a merge conflict in your code, you will be warned in Looker after you commit changes and pull from production:

When Looker shows the merge-conflict warning, it is recommended that you resolve the merge conflict before making any further changes. Pushing a merge conflict to production will cause parse errors that may prevent exploration of your data. If you are an advanced Git user and you want to move forward with pushing changes, click the Don’t Resolve button.

In the LookML file itself, the lines with conflicts are marked like this:

<<<<<<< HEAD Your code ======= Production code >>>>>>> branch 'master'

Looker shows the following merge markers to indicate the merge conflicts:

In the preceding example, your code represents the changes you committed, and production code represents the code into which Git could not automatically merge your changes.

To resolve a merge conflict:

  1. Find the files with merge conflicts. Looker marks these files in red, or you can also search your project for merge markers, such as <<<< or HEAD, to find all the conflicts in your project. You can also find affected files by clicking the files link in the merge warning that appears in the Git Actions panel.
  2. In the file, go to the lines with merge conflicts and delete the version of the text that you do NOT want to keep, and also delete all the merge conflict markers.
  3. Save the file, and repeat the preceding steps for any other files marked with merge conflicts.

TIP: Search your project for each of the merge markers to verify that you have resolved all conflicts and deleted all the merge markers. Make sure to remove all instances of merge markers in your LookML files. These markers will cause parse errors that can prevent users from exploring your data.

  1. After you have resolved all merge conflicts and deleted all merge markers from your project, commit the changes and deploy them to production.

Now that you have resolved the merge conflict and pushed your resolution to production, other developers can pull from production and continue work as usual.

Git garbage collection

Git garbage collection cleans up unnecessary files and compresses file revisions to optimize your Git repository. Git garbage collection (git gc) is run automatically when your Looker instance is updated or rebooted. To keep from running git gc too often, Looker waits 30 days since the last git gc and then runs git gc on the next reboot.

In rare cases, you might try to Push Changes to Remote or Push Branch to Remote while git gc is running. If Looker displays an error, wait for a minute or two and then try again to push your changes.