<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=32863) </details> <!--IssueSummary end--> ### Problem to solve Render PlantUML diagrams in a "preview" similar to how markdowns can be previewed. When I review merge requests that contain PlantUML diagrams, it's tedius to have to copy-paste and render the diagram myself to view it. ### Intended users All personas could benefit from this feature if they use PlantUML. * [Parker (Product Manager)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#parker-product-manager) * [Delaney (Development Team Lead)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#delaney-development-team-lead) * [Sasha (Software Developer)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#sasha-software-developer) * [Presley (Product Designer)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#presley-product-designer) * [Devon (DevOps Engineer)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#devon-devops-engineer) * [Sidney (Systems Administrator)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#sidney-systems-administrator) * [Sam (Security Analyst)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#sam-security-analyst) * [Dana (Data Analyst)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#dana-data-analyst) ### Further details We manage and propose workflows, architectures, and processes using PlantUML diagrams. The benefit of previewing these in a merge request is to reduce the time it takes to perform the reviews. <!-- Include use cases, benefits, and/or goals (contributes to our vision?) --> ### Proposal <!-- How are we going to solve the problem? Try to include the user journey! https://about.gitlab.com/handbook/journeys/#user-journey --> ### Permissions and Security <!-- What permissions are required to perform the described actions? Are they consistent with the existing permissions as documented for users, groups, and projects as appropriate? Is the proposed behavior consistent between the UI, API, and other access methods (e.g. email replies)?--> ### Documentation <!-- See the Feature Change Documentation Workflow https://docs.gitlab.com/ee/development/documentation/feature-change-workflow.html Add all known Documentation Requirements here, per https://docs.gitlab.com/ee/development/documentation/feature-change-workflow.html#documentation-requirements If this feature requires changing permissions, this document https://docs.gitlab.com/ee/user/permissions.html must be updated accordingly. --> ### Testing Rendering PlantUML diagrams requires CPU and memory use that could be challenging at scale. ### What does success look like, and how can we measure that? When I am viewing a PlantUML file, I can quickly see the rendered version of it. ### What is the type of buyer? We are an enterprise. ### Links / references http://plantuml.com/