--- 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 the [PlantUML](https://plantuml.com) integration is enabled and configured in GitLab, you can create diagrams in snippets, wikis, and repositories. This integration is enabled on GitLab.com for all SaaS users and does not require any additional configuration. To set up the integration on a self-managed instance, 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** files with the extension `.md`: ````markdown ```plantuml Bob -> Alice : hello Alice -> Bob : hi ``` ```` For additional acceptable extensions, review the [`languages.yaml`](https://gitlab.com/gitlab-org/gitlab/-/blob/master/vendor/languages.yml#L3174) file. - **AsciiDoc** files with the extension `.asciidoc`, `.adoc`, or `.asc`: ```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. On the top bar, select **Main menu > Admin**. 1. On the left sidebar, go to **Settings > General** and expand the **PlantUML** section. 1. Select the **Enable PlantUML** checkbox. 1. Set the PlantUML instance as `https://gitlab.example.com/-/plantuml/`, and select **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' } ``` In GitLab Helm chart, you can set it by adding a variable to the [global.extraEnv](https://gitlab.com/gitlab-org/charts/gitlab/blob/master/doc/charts/globals.md#extraenv) section, like this: ```yaml global: extraEnv: 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.