[FLINK-30921][ci] Adds mirrors instead of relying on a single source for Ubuntu packages

We don't want to rely on an external service for retrieving mirrors dynamically
to prevent supply chain attacks. Therefore, we selected a few mirrors manually.
This prevents us from relying on a dynamic mirror list based on the CI machines
location which might be a performance issue. But generally, we want to rely on
the Azure mirror anyway. The fallback list is only meant to jump in if Azure's
mirror is not accessible temporarily.

Signed-off-by: Matthias Pohl <matthias.pohl@aiven.io>

tools/azure-pipelines/e2e-template.yml

@@ -100,6 +100,15 @@ jobs:
         source ./tools/ci/maven-utils.sh
         setup_maven
 
+        # the APT mirrors access is based on a proposal from https://github.com/actions/runner-images/issues/7048#issuecomment-1419426054
+        echo "Configure APT mirrors"
+        mirror_file_path="/etc/apt/mirrors.txt"
+        default_ubuntu_mirror_url="http://azure.archive.ubuntu.com/ubuntu/"
+        
+        sudo cp ./tools/ci/ubuntu-mirror-list.txt ${mirror_file_path}
+        sudo sed -i "s~${default_ubuntu_mirror_url}~mirror+file:${mirror_file_path}~" /etc/apt/sources.list
+        sudo apt-get update
+
         echo "Installing required software"
         sudo apt-get install -y bc libapr1
         # install libssl1.0.0 for netty tcnative

tools/ci/ubuntu-mirror-list.txt

@@ -0,0 +1,40 @@
+################################################################################
+#  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.
+################################################################################
+
+# This mirror list can be used in CI to set up the Docker containers without only
+# relying on the default Ubuntu mirror provided by Azure.
+# FYI: apt ignores lines that are empty or start with '#'
+# see https://manpages.ubuntu.com/manpages/jammy/en/man1/apt-transport-mirror.1.html for further documentation
+
+# primary mirror
+http://azure.archive.ubuntu.com/ubuntu/	priority:1
+
+# fallback mirrors selected from http://mirrors.ubuntu.com/ based on the assumption that CI
+# is running on AliCloud machines or Azure machines located in the US
+
+# US-located mirrors
+http://mirrors.ocf.berkeley.edu/ubuntu/
+http://mirror.math.ucdavis.edu/ubuntu/
+http://mirrors.mit.edu/ubuntu/
+https://mirror.ubuntu.serverforge.org/
+
+# AliCloud mirror
+http://mirrors.aliyun.com/ubuntu/
+
+# general
+http://archive.ubuntu.com/ubuntu/