Add Ubuntu-Slim image definition (#13423)

Add ubuntu-slim image definition

images/ubuntu-slim/scripts/build/configure-environment.sh

@@ -0,0 +1,72 @@
+#!/bin/bash -e
+################################################################################
+##  File:  configure-environment.sh
+##  Desc:  Configure system and environment
+################################################################################
+
+# Source the helpers for use with the script
+source $HELPER_SCRIPTS/os.sh
+source $HELPER_SCRIPTS/etc-environment.sh
+
+whoami
+
+# Set ImageVersion and ImageOS env variables
+set_etc_environment_variable "ImageVersion" "${IMAGE_VERSION}"
+set_etc_environment_variable "ImageOS" "${IMAGE_OS}"
+
+# Set the ACCEPT_EULA variable to Y value to confirm your acceptance of the End-User Licensing Agreement
+set_etc_environment_variable "ACCEPT_EULA" "Y"
+
+# This directory is supposed to be created in $HOME and owned by user(https://github.com/actions/runner-images/issues/491)
+mkdir -p /etc/skel/.config/configstore
+set_etc_environment_variable "XDG_CONFIG_HOME" '$HOME/.config'
+
+# Prepare directory and env variable for toolcache
+echo "Setting up AGENT_TOOLSDIRECTORY and RUNNER_TOOL_CACHE variable to /opt/hostedtoolcache"
+AGENT_TOOLSDIRECTORY=/opt/hostedtoolcache
+mkdir $AGENT_TOOLSDIRECTORY
+set_etc_environment_variable "AGENT_TOOLSDIRECTORY" "${AGENT_TOOLSDIRECTORY}"
+set_etc_environment_variable "RUNNER_TOOL_CACHE" "${AGENT_TOOLSDIRECTORY}"
+chmod -R 777 $AGENT_TOOLSDIRECTORY
+
+# https://www.elastic.co/guide/en/elasticsearch/reference/current/vm-max-map-count.html
+# https://www.suse.com/support/kb/doc/?id=000016692
+echo 'vm.max_map_count=262144' | tee -a /etc/sysctl.conf
+
+# https://kind.sigs.k8s.io/docs/user/known-issues/#pod-errors-due-to-too-many-open-files
+echo 'fs.inotify.max_user_watches=655360' | tee -a /etc/sysctl.conf
+echo 'fs.inotify.max_user_instances=1280' | tee -a /etc/sysctl.conf
+
+# https://github.com/actions/runner-images/issues/9491
+echo 'vm.mmap_rnd_bits=28' | tee -a /etc/sysctl.conf
+
+# https://github.com/actions/runner-images/pull/7860
+netfilter_rule='/etc/udev/rules.d/50-netfilter.rules'
+rules_directory="$(dirname "${netfilter_rule}")"
+mkdir -p $rules_directory
+touch $netfilter_rule
+echo 'ACTION=="add", SUBSYSTEM=="module", KERNEL=="nf_conntrack", RUN+="/usr/sbin/sysctl net.netfilter.nf_conntrack_tcp_be_liberal=1"' | tee -a $netfilter_rule
+
+# Remove fwupd if installed. We're running on VMs in Azure and the fwupd package is not needed.
+# Leaving it enable means periodic refreshes show in network traffic and firewall logs
+# Check if fwupd-refresh.timer exists in systemd
+if systemctl list-unit-files fwupd-refresh.timer &>/dev/null; then
+    echo "Masking fwupd-refresh.timer..."
+    systemctl mask fwupd-refresh.timer
+fi
+
+# This is a legacy check, leaving for earlier versions of Ubuntu
+# If fwupd config still exists, disable the motd updates
+if [[ -f "/etc/fwupd/daemon.conf" ]]; then
+    sed -i 's/UpdateMotd=true/UpdateMotd=false/g' /etc/fwupd/daemon.conf
+fi
+
+# Disable to load providers
+# https://github.com/microsoft/azure-pipelines-agent/issues/3834
+if is_ubuntu22; then
+    sed -i 's/openssl_conf = openssl_init/#openssl_conf = openssl_init/g' /etc/ssl/openssl.cnf
+fi
+
+# # Disable man-db auto update
+# echo "set man-db/auto-update false" | debconf-communicate
+# dpkg-reconfigure man-db