Document the DAST report format

Problem to solve

Integrators and users who want to use a 3rd-party DAST tool need to output their results in our report format for GitLab to be able to process it. However, this is not publicly documented anywhere except for the source code of the product itself. This makes it difficult for those people to be successful, which means they either give up or must ask GitLab staff for help.

Intended users

• 3rd-party integrators

Proposal

Update docs.gitlab.com to include descriptions of the DAST report format so that integrators and customers with 3rd-party scanners can output their results in the correct format.

Specifically, these pages must be updated:

1. DAST Reports section
2. Security scanner integration
   1. This can reference the DAST documentation, rather than duplicate the content

Permissions and Security

Should publicly visible on docs.gitlab.com