Artifact browser does not serve .log and .txt files by pages on Gitlab.com

Summary

On Gitlab.com .log and .txt files are not opened in the browser like .html but instead offered as download. This is even though the extension is included in the EXTENSIONS_SERVED_BY_PAGES array.

Steps to reproduce

1. Have a build job which has a .txt, .log and .html file as artifact on Gitlab.com
2. Open the artifact browser
3. Click on the .html file, it will open directly in the browser ✔️
4. Click on the .log file or .txt. It will not open in the browser ☠️

stages:
  - build

BuildJob:
  stage: build
  tags:
    - docker
  script:
    - echo "building"
    - echo "some data for the file" >> testartifact.txt
    - echo "some log data for the file" >> testartifact.log
    - echo "<h1>Header</h1>Body" >> testartifact.html
    - echo "{}" >> testartifact.json
    - echo "<a b=\"bbb\">Some entry</a>" >> testartifact.xml
  artifacts:
    when: always
    expire_in: 5 days
    paths:
      - testartifact.txt
      - testartifact.log
      - testartifact.html
      - testartifact.json
      - testartifact.xml

Note that Self-manged installations using built-in Nginx do not have this issue.

Example Project

This is an example job showing the behavior on Gitlab.com:

• https://gitlab.com/gitlab-gold/kategrechishkinatestgroup/zd403807-artifactpreview/-/jobs/4249609293
• https://gitlab.com/PhilLab/testing-private/-/jobs/474999442

What is the current bug behavior?

.log and .txt files are offered as download

What is the expected correct behavior?

.log and .txt files should be handled just like .html and shown in the browser

Output of checks

This bug happens on GitLab.com

Steps for remediation fixes

1. Adjust documentation to reflect differences on SaaS vs Self-Managed
2. Adjust icons to reflect proper behavior
3. Adjust documentation to reflect change of icons and suggested behavior