#!/bin/bash
set -e

# ansible.builtin.script:
#   chdir: /root

# just in case one runs the script outside ansible
[[ `pwd` != /root ]] && echo error: assuming current working directory /root/ && exit 1

[[ ! -x `which dpkg` ]]		&& echo error: dpkg executable not found && exit 1
[[ ! -x `which wget` ]]		&& echo error: wget executable not found && exit 1
[[ ! -x `which curl` ]]		&& echo error: curl executable not found && exit 1
[[ ! -x `which lsb_release` ]]	&& echo error: lsb_release executable not found && exit 1

# ok=1 changed=0
dpkg -s yandex-unified-agent >/dev/null 2>&1 && echo ok - yandex-unified-agent package is there - nothing to do && exit 0

# in case it was installed from source
# ok=1 changed=0
[[ -f /etc/yandex/unified_agent/config.yml ]] && echo ok - /etc/yandex/unified_agent/config.yml is there - nothing to do && exit 0

distro=`lsb_release -cs`

# using same correspondance for unified agent as for Ansible itself
# https://docs.ansible.com/ansible/latest/installation_guide/installation_distros.html#installing-ansible-on-debian
# bookworm ==> jammy
# bullseye ==> focal
# buster   ==> bionic

# https://yandex.cloud/en/docs/monitoring/concepts/data-collection/unified-agent/installation#deb_1
if [[ $distro = bookworm ]]; then
        ubuntu_name=ubuntu-22.04-jammy
elif [[ $distro = jammy ]]; then
        ubuntu_name=ubuntu-22.04-jammy
elif [[ $distro = bullseye ]]; then
        ubuntu_name=ubuntu-20.04-focal
elif [[ $distro = focal ]]; then
        ubuntu_name=ubuntu-20.04-focal
else
        echo error: $distro - unknown linux distribution codename
        exit 1
fi

ua_version=`(curl -s https://storage.yandexcloud.net/yc-unified-agent/all-versions; echo) | tail -1`

echo latest ua version is $ua_version

file=yandex-unified-agent_${ua_version}_amd64.deb

if [[ -f $file ]]; then
        echo $file already there
else
        echo -n download $file ...
        wget -q "https://storage.yandexcloud.net/yc-unified-agent/releases/$ua_version/deb/$ubuntu_name/$file" && echo done
fi

[[ ! -f $file ]] && echo error: failed to download package file && exit 1

echo -n install $file ...
DEBIAN_FRONTEND=noninteractive dpkg -i $file >/dev/null 2>&1 && echo done

# eventually failed=1
echo -n checking for yandex-unified-agent package ...
dpkg -s yandex-unified-agent >/dev/null 2>&1 && echo done

# clean-up package file
rm -f $file || true

# handy symlink to remind sysadmin about the agent
ln -s /etc/yandex/unified_agent/config.yml 2>/dev/null || true

# ok=1 changed=1
echo changed - all done