#! /bin/bash

##### Constants
DOCKER_LIB_HOME=/home/docker/lib/
STEP_COUNT=1
# YOUR_REGISTRY_MIRROR
DOCKER_REGISTRY_MIRROR="$1"
DOCKER_PRIVATE_REGISTRY=foo.registry.docker:5000
CUSTOM_BASE_REPO='http://mirrors.aliyun.com/repo/Centos-7.repo'
CUSTOM_EPEL_REPO='http://mirrors.aliyun.com/repo/epel-7.repo'

##### Functions
function command_installed(){
    if [[ -n "$1" ]] && (type "$1" &> /dev/null ); then
        return 0; # true
    fi
    return 1;
}

function service_started(){
    if [[ -n "$1" ]]; then
        info=$(systemctl status $1 | grep 'Active' )
        read prefix status rest <<<"$info"
        if [[ $status == 'active' ]]; then
            return 0;
        fi
    fi
    return 1;   
}

function custom_base_repo(){
    mv /etc/yum.repos.d/CentOS-Base.repo{,.backup}
    curl -o /etc/yum.repos.d/CentOS-Base.repo $CUSTOM_BASE_REPO
    yum clean all && rm -rf /var/cache/yum
}

function custom_epel_repo(){
    yum makecache
    yum -y install epel-release

    mv /etc/yum.repos.d/epel.repo{,.backup}
    mv /etc/yum.repos.d/epel-testing.repo{,.backup}

    curl -o /etc/yum.repos.d/epel.repo $CUSTOM_EPEL_REPO
    yum clean all && rm -rf /var/cache/yum
}

function install_common_package(){
    echo "########################"
    echo " $STEP_COUNT. install common tools"
    echo "########################"
    
    if command_installed 'pip' && command_installed 'git' &&  command_installed 'iptables'; then
        echo "common packages must be already installed."
    else
        custom_base_repo
        custom_epel_repo
        yum makecache
        yum install -y net-tools vim git \
            ntsysv setuptool yum-utils python-pip python-setuptools \
            lsof bzip2 unzip tar gcc wget nfs-utils \
            device-mapper-persistent-data lvm2
        yum install -y policycoreutils-python
        mkdir ~/.pip/
        tee ~/.pip/pip.conf <<-'EOF'
[global]
index-url = http://mirrors.aliyun.com/pypi/simple/
[install]
trusted-host=mirrors.aliyun.com
EOF
    fi

    add_step_count 
}

function install_docker_engine(){

    docker_repo_file=/etc/yum.repos.d/docker-ce.repo
    docker_config_dir=/etc/systemd/system/docker.service.d

    echo "########################"
    echo " $STEP_COUNT. install docker engine"
    echo "########################"

    if [ ! -d ${DOCKER_LIB_HOME} ]; then
        mkdir -p ${DOCKER_LIB_HOME}
    fi

    if command_installed 'docker'; then
        echo "docker engine must be already installed."
    else
        yum-config-manager \
            --add-repo \
            https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
        if [[ ! -s ${docker_repo_file} ]]; then
            # retry tsinghua mirror
            yum-config-manager \
                --add-repo \
                https://download.docker.com/linux/centos/docker-ce.repo
            sed -i 's+download.docker.com+mirrors.tuna.tsinghua.edu.cn/docker-ce+' /etc/yum.repos.d/docker-ce.repo
        fi
        yum makecache fast
        # Uninstall old versions
        yum remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-engine

        yum install -y docker-ce docker-ce-cli containerd.io
        mkdir -p ${docker_config_dir}
        if [[ -n "$DOCKER_REGISTRY_MIRROR" ]]; then
            tee "$docker_config_dir/docker.conf" <<-EOF
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd \
  --insecure-registry ${DOCKER_PRIVATE_REGISTRY} \
  --graph=${DOCKER_LIB_HOME} \
  --registry-mirror=${DOCKER_REGISTRY_MIRROR}
EOF
        else
            tee "$docker_config_dir/docker.conf" <<-EOF
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd \
  --insecure-registry ${DOCKER_PRIVATE_REGISTRY} \
  --graph=${DOCKER_LIB_HOME}
EOF
        fi
        systemctl daemon-reload
        systemctl restart docker
        systemctl enable docker
        # enable IPv4
        sysctl -w net.ipv4.ip_forward=1

    fi

    add_step_count
}

function install_docker_compose(){
    echo "########################"
    echo " $STEP_COUNT. install Docker-Compose"
    echo "########################"

    if command_installed 'docker-compose'; then
        echo "docker-compose must be already installed."
    else
        pip install docker-compose 
    fi

    add_step_count
}

function install_supervisor(){
    echo "########################"
    echo " $STEP_COUNT. install Supervisor"
    echo "########################"

    if command_installed 'supervisord'; then
        echo "supervisord must be already installed."
    else
        pip install --upgrade pip
        pip install supervisor
    fi

    mkdir -p /etc/supervisor /etc/supervisor/conf.d/

    echo_supervisord_conf > /etc/supervisor/supervisord.conf

    echo '[include]'>>/etc/supervisor/supervisord.conf
    echo 'files = /etc/supervisor/conf.d/*.ini'>>/etc/supervisor/supervisord.conf

    sudo tee /usr/lib/systemd/system/supervisord.service<<-'EOF'
[Unit]
Description=Supervisor daemon
    
[Service]
Type=forking
ExecStart=/usr/bin/supervisord -c /etc/supervisor/supervisord.conf
ExecStop=/usr/bin/supervisorctl $OPTIONS shutdown
ExecReload=/usr/bin/supervisorctl $OPTIONS reload
KillMode=process
Restart=on-failure
RestartSec=42s
    
[Install]
WantedBy=multi-user.target
EOF

    add_step_count
}

function add_step_count(){
    ((STEP_COUNT++))
}

function main(){
    install_common_package
    install_docker_engine
    install_docker_compose
    install_supervisor
}

main