--- stage: Create group: Source Code info: "To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments" type: reference, howto --- # PlantUML and GitLab **(FREE)** When [PlantUML](https://plantuml.com) integration is enabled and configured in GitLab, you can create diagrams in snippets, wikis, and repositories. To set up the integration, you must: 1. [Configure your PlantUML server](#configure-your-plantuml-server). 1. [Configure local PlantUML access](#configure-local-plantuml-access). 1. [Configure PlantUML security](#configure-plantuml-security). 1. [Enable the integration](#enable-plantuml-integration). After completing the integration, PlantUML converts `plantuml` blocks to an HTML image tag, with the source pointing to the PlantUML instance. The PlantUML diagram delimiters `@startuml`/`@enduml` aren't required, as these are replaced by the `plantuml` block: - **Markdown** ````markdown ```plantuml Bob -> Alice : hello Alice -> Bob : hi ``` ```` - **AsciiDoc** ```plaintext [plantuml, format="png", id="myDiagram", width="200px"] ---- Bob->Alice : hello Alice -> Bob : hi ---- ``` - **reStructuredText** ```plaintext .. plantuml:: :caption: Caption with **bold** and *italic* Bob -> Alice: hello Alice -> Bob: hi ``` Although you can use the `uml::` directive for compatibility with [`sphinxcontrib-plantuml`](https://pypi.org/project/sphinxcontrib-plantuml/), GitLab supports only the `caption` option. If the PlantUML server is correctly configured, these examples should render a diagram instead of the code block: ```plantuml Bob -> Alice : hello Alice -> Bob : hi ``` Inside the block you can add any of the diagrams PlantUML supports, such as: - [Activity](https://plantuml.com/activity-diagram-legacy) - [Class](https://plantuml.com/class-diagram) - [Component](https://plantuml.com/component-diagram) - [Object](https://plantuml.com/object-diagram) - [Sequence](https://plantuml.com/sequence-diagram) - [State](https://plantuml.com/state-diagram) - [Use Case](https://plantuml.com/use-case-diagram) You can add parameters to block definitions: - `format`: Can be either `png` (default) or `svg`. Use `svg` with care, as it's not supported by all browsers, and isn't supported by Markdown. - `id`: A CSS ID added to the diagram HTML tag. - `width`: Width attribute added to the image tag. - `height`: Height attribute added to the image tag. Markdown does not support any parameters, and always uses PNG format. ## Configure your PlantUML server Before you can enable PlantUML in GitLab, set up your own PlantUML server to generate the diagrams: - [In Docker](#docker). - [In Debian/Ubuntu](#debianubuntu). ### Docker To run a PlantUML container in Docker, run this command: ```shell docker run -d --name plantuml -p 8080:8080 plantuml/plantuml-server:tomcat ``` The **PlantUML URL** is the hostname of the server running the container. When running GitLab in Docker, it must have access to the PlantUML container. To achieve that, use [Docker Compose](https://docs.docker.com/compose/). In this basic `docker-compose.yml` file, PlantUML is accessible to GitLab at the URL `http://plantuml:8080/`: ```yaml version: "3" services: gitlab: image: 'gitlab/gitlab-ee:12.2.5-ee.0' environment: GITLAB_OMNIBUS_CONFIG: | nginx['custom_gitlab_server_config'] = "location /-/plantuml/ { \n proxy_cache off; \n proxy_pass http://plantuml:8080/; \n}\n" plantuml: image: 'plantuml/plantuml-server:tomcat' container_name: plantuml ``` ### Debian/Ubuntu You can install and configure a PlantUML server in Debian/Ubuntu distributions using Tomcat: 1. Run these commands to create a `plantuml.war` file from the source code: ```shell sudo apt-get install graphviz openjdk-8-jdk git-core maven git clone https://github.com/plantuml/plantuml-server.git cd plantuml-server mvn package ``` 1. Deploy the `.war` file from the previous step with these commands: ```shell sudo apt-get install tomcat8 sudo cp target/plantuml.war /var/lib/tomcat8/webapps/plantuml.war sudo chown tomcat8:tomcat8 /var/lib/tomcat8/webapps/plantuml.war sudo service tomcat8 restart ``` The Tomcat service should restart. After the restart is complete, the PlantUML service is ready and listening for requests on port 8080: `http://localhost:8080/plantuml` To change these defaults, edit the `/etc/tomcat8/server.xml` file. NOTE: The default URL is different when using this approach. The Docker-based image makes the service available at the root URL, with no relative path. Adjust the configuration below accordingly. ## Configure local PlantUML access The PlantUML server runs locally on your server, so it can't be accessed externally by default. Your server must catch external PlantUML calls to `https://gitlab.example.com/-/plantuml/` and redirect them to the local PlantUML server. Depending on your setup, the URL is either of the following: - `http://plantuml:8080/` - `http://localhost:8080/plantuml/` If you're running [GitLab with TLS](https://docs.gitlab.com/omnibus/settings/ssl.html) you must configure this redirection, because PlantUML uses the insecure HTTP protocol. Newer browsers such as [Google Chrome 86+](https://www.chromestatus.com/feature/4926989725073408) don't load insecure HTTP resources on pages served over HTTPS. To enable this redirection: 1. Add the following line in `/etc/gitlab/gitlab.rb`, depending on your setup method: ```ruby # Docker deployment nginx['custom_gitlab_server_config'] = "location /-/plantuml/ { \n proxy_cache off; \n proxy_pass http://plantuml:8080/; \n}\n" # Built from source nginx['custom_gitlab_server_config'] = "location /-/plantuml { \n rewrite ^/-/(plantuml.*) /$1 break;\n proxy_cache off; \n proxy_pass http://localhost:8080/plantuml; \n}\n" ``` 1. To activate the changes, run the following command: ```shell sudo gitlab-ctl reconfigure ``` ### Configure PlantUML security PlantUML has features that allow fetching network resources. If you self-host the PlantUML server, put network controls in place to isolate it. ```plaintext @startuml start ' ... !include http://localhost/ stop; @enduml ``` ## Enable PlantUML integration After configuring your local PlantUML server, you're ready to enable the PlantUML integration: 1. Sign in to GitLab as an [Administrator](../../user/permissions.md) user. 1. In the top menu, click **{admin}** **Admin Area**. 1. In the left sidebar, go to **Settings > General** and expand the **PlantUML** section. 1. Select the **Enable PlantUML** check box. 1. Set the PlantUML instance as `https://gitlab.example.com/-/plantuml/`, and click **Save changes**. Depending on your PlantUML and GitLab version numbers, you may also need to take these steps: - For PlantUML servers running v1.2020.9 and above, such as [plantuml.com](https://plantuml.com), you must set the `PLANTUML_ENCODING` environment variable to enable the `deflate` compression. In Omnibus GitLab, you can set this value in `/etc/gitlab.rb` with this command: ```ruby gitlab_rails['env'] = { 'PLANTUML_ENCODING' => 'deflate' } ``` - For GitLab versions 13.1 and later, PlantUML integration now [requires a header prefix in the URL](https://github.com/plantuml/plantuml/issues/117#issuecomment-6235450160) to distinguish different encoding types.