How to delete gitlab CI jobs pipelines logs/builds and history

Mass deletion script fixed for the lazy, delete X pipelines from the oldest (Linux systems).

Note: need jq.

#!/bin/bash
set -e

TOKEN="__SET_YOUR_PERSONAL_ACCESS_TOKEN__"
# Visible under name of project page.
PROJECT_ID="__SET_NUMERIC_PROJECT_ID__"
# Set your gitlab instance url.
GITLAB_INSTANCE="https://gitlab.com/api/v4/projects"
# How many to delete from the oldest, 100 is the maximum, above will just remove 100.
PER_PAGE=100

for PIPELINE in $(curl --header "PRIVATE-TOKEN: $TOKEN" "$GITLAB_INSTANCE/$PROJECT_ID/pipelines?per_page=$PER_PAGE&sort=asc" | jq '.[].id') ; do
    echo "Deleting pipeline $PIPELINE"
    curl --header "PRIVATE-TOKEN: $TOKEN" --request "DELETE" "$GITLAB_INSTANCE/$PROJECT_ID/pipelines/$PIPELINE"
done

UPDATE

As of Gitlab Release 12.6, deleting a pipeline is now an option in the GUI for owners:

• Click the pipeline you want to remove in the pipelines list
• Hit the red Delete button in the upper right of the pipeline details page.

As of Gitlab Release 11.6, deleting a pipeline is now an option, for maintainers only, via the API.

You need:

• An API token
• The id of the project
• The pipeline_id of the pipeline you wish to remove.

Example using curl from the docs for project id: 1 and pipeline_id: 4:

curl --header "PRIVATE-TOKEN: <your_access_token>" --request "DELETE" "https://gitlab.example.com/api/v4/projects/1/pipelines/46"

Documentation is here