Improves deletion of old artifacts. (#11079)

We introduced deletion of the old artifacts as this was
the suspected culprit of Kubernetes Job failures. It turned out
eventually that those Kubernetes Job failures were caused by
the #11017 change, but it's good to do housekeeping of the
artifacts anyway.

The delete workflow action introduced in a hurry had two problems:

* it runs for every fork if they sync master. This is a bit
  too invasive

* it fails continuously after 10 - 30 minutes every time
  as we have too many old artifacts to delete (GitHub has
  90 days retention policy so we have likely tens of
  thousands of artifacts to delete)

* it runs every hour and it causes occasional API rate limit
  exhaustion (because we have too many artifacts to loop trough)

This PR introduces filtering with the repo, changes the frequency
of deletion to be 4 times a day. Back of the envelope calculation
tops 4/day at 2500 artifacts to delete at every run so we have low risk 
of reaching 5000 API calls/hr rate limit. and adds script that we are
running manually to delete those excessive artifacts now. Eventually
when the number of artifacts goes down the regular job should delete
maybe a few hundreds of artifacts appearing within the 6 hours window
in normal circumstances and it should stop failing then.

Author: potiuk

.github/workflows/delete_old_artifacts.yml

@@ -1,11 +1,12 @@
 name: 'Delete old artifacts'
 on:
   schedule:
-    - cron: '0 * * * *' # every hour
+    - cron: '27 */6 * * *' # run every 6 hours
 
 jobs:
   delete-artifacts:
     runs-on: ubuntu-latest
+    if: github.repository == 'apache/airflow'
     steps:
       - uses: kolpav/purge-artifacts-action@v1
         with:

CI.rst

@@ -615,6 +615,16 @@ This is manually triggered workflow (via GitHub UI manual run) that should only
 When triggered, it will force-push the "apache/airflow" master to the fork's master. It's the easiest
 way to sync your fork master to the Apache Airflow's one.
 
+Delete old artifacts
+--------------------
+
+This workflow is introduced, to delete old artifacts from the Github Actions build. We set it to
+delete old artifacts that are > 7 days old. It only runs for the 'apache/airflow' repository.
+
+We also have a script that can help to clean-up the old artifacts:
+`remove_artifacts.sh <dev/remove_artifacts.sh>`_
+
+
 Naming conventions for stored images
 ====================================
 

dev/remove_artifacts.sh

@@ -0,0 +1,84 @@
+#!/usr/bin/env bash
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+set -euo pipefail
+
+# Parameters:
+#
+# GITHUB_REPO - repository to delete the artifacts
+# GITHUB_USER - your personal user name
+# GITHUB_TOKEN - your personal token with `repo` scope
+#
+GITHUB_REPO=https://api.github.com/repos/apache/airflow
+readonly GITHUB_REPO
+
+if [[ -z ${GITHUB_USER} ]]; then
+    echo 2>&1
+    echo 2>&1 "Set GITHUB_USER variable to your user"
+    echo 2>&1
+    exit 1
+fi
+readonly GITHUB_USER
+
+if [[ -z ${GITHUB_TOKEN} ]]; then
+    echo 2>&1
+    echo 2>&1 "Set GITHUB_TOKEN variable to a token with 'repo' scope"
+    echo 2>&1
+    exit 2
+fi
+GITHUB_TOKEN=${GITHUB_TOKEN}
+readonly GITHUB_TOKEN
+
+function github_api_call() {
+    curl --silent --location --user "${GITHUB_USER}:${GITHUB_TOKEN}" "$@"
+}
+
+# A temporary file which receives HTTP response headers.
+TEMPFILE=$(mktemp)
+readonly TEMPFILE
+
+function loop_through_artifacts_and_delete() {
+
+    # Process all artifacts on this repository, loop on returned "pages".
+    artifact_url=${GITHUB_REPO}/actions/artifacts
+
+    while [[ -n "${artifact_url}" ]]; do
+        # Get current page, get response headers in a temporary file.
+        json=$(github_api_call --dump-header "${TEMPFILE}" "$artifact_url")
+
+        # Get artifact_url of next page. Will be empty if we are at the last page.
+        artifact_url=$(grep '^Link:' "$TEMPFILE" | tr ',' '\n' | \
+            grep 'rel="next"' | head -1 | sed -e 's/.*<//' -e 's/>.*//')
+        rm -f "${TEMPFILE}"
+
+        # Number of artifacts on this page:
+        count=$(($(jq <<<"${json}" -r '.artifacts | length')))
+
+        # Loop on all artifacts on this page.
+        for ((i = 0; "${i}" < "${count}"; i++)); do
+            # Get the name of artifact and count instances of this name
+            name=$(jq <<<"${json}" -r ".artifacts[$i].name?")
+            id=$(jq <<<"${json}" -r ".artifacts[$i].id?")
+            size=$(($(jq <<<"${json}" -r ".artifacts[$i].size_in_bytes?")))
+            printf "Deleting '%s': [%s] : %'d bytes\n" "${name}" "${id}" "${size}"
+            github_api_call -X DELETE "${GITHUB_REPO}/actions/artifacts/${id}"
+            sleep 1 # There is a Github API limit of 5000 calls/hr. This is to limit the API calls below that
+        done
+    done
+}
+
+loop_through_artifacts_and_delete