common

#! /bin/bash


# =============================================================================
# NAME: display_section
# DESC: display a section / title on the output
# =============================================================================
# $1 message to display
# =============================================================================
function  display_section() {
    # echo -e "\033[0;1;4m$1\033[0;0m"
    printf "\033[0;1;4m%s\033[0;0m\n" "$1"
}

# =============================================================================
# NAME: display_message
# DESC: display a message / title on the output
# =============================================================================
# $1 message
# $2 status
# =============================================================================
function  display_message() {
    case "${2^^}" in
        "OK") COLOR="\033[0;32m";;
        "KO") COLOR="\033[0;31m";;
        "ERROR") COLOR="\033[0;31m";;
        "WARN") COLOR="\033[0;33m";;
        "INFO") COLOR="\033[1;34m";;
    esac
    printf "$(date '+%Y-%m-%d %H:%M:%S') [$COLOR${2}\033[0;0m] - $(hostname): $1\n"
}

# =============================================================================
# NAME: display_message_result
# DESC: display a message / title on the output using the last command result
#       as OK / KO status flag
# =============================================================================
# $1 message
# =============================================================================
function  display_message_result() {
    if [ "$?" -eq 0 ];
    then
        display_message "$1" "OK"

    else
        display_message "$1" "KO"
        exit 1
    fi
}


# =============================================================================
# NAME: common_install
# DESC: install the kubernetes commands like kubeadm and kubectl
# =============================================================================

function common_install() {
    display_section "Configure repositories & install packages"
    apt update  > /dev/null 2>&1
    display_message_result "Updating package repository"
    apt install -y curl gnupg2 software-properties-common apt-transport-https ca-certificates > /dev/null 2>&1
    display_message_result "Installing base needed packages"

    mkdir -p /etc/apt/keyrings

    rm -f /etc/apt/trusted.gpg.d/docker.gpg 
    curl -fsSL "https://download.docker.com/linux/$(lsb_release -a 2> /dev/null|grep 'Distributor ID:'|cut -d$'\t' -f2|tr '[:upper:]' '[:lower:]')/gpg" | gpg --dearmour -o /etc/apt/trusted.gpg.d/docker.gpg 
    display_message_result "Adding docker package repository signature"

    add-apt-repository --yes "deb [arch=$(dpkg --print-architecture)] https://download.docker.com/linux/$(lsb_release -a 2> /dev/null|grep "Distributor ID:"|cut -d$'\t' -f2|tr '[:upper:]' '[:lower:]') $(lsb_release -cs) stable"
    display_message_result "Adding docker package repository"
   
    rm -f /etc/apt/keyrings/kubernetes-apt-keyring.gpg
    curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.29/deb/Release.key -a 2> /dev/null| gpg --dearmour -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
    display_message_result "Adding google package repository signature"
    chmod 644 /etc/apt/keyrings/kubernetes-apt-keyring.gpg

    echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.29/deb/ /' | tee /etc/apt/sources.list.d/kubernetes.list > /dev/null
    display_message_result "Adding google package repository"
    chmod 644 /etc/apt/sources.list.d/kubernetes.list

    apt update  > /dev/null 2>&1
    display_message_result "Updating package repository"

    apt install -y kubectl > /dev/null 2>&1
    display_message_result "Installing kubectl"

    apt-mark hold kubectl > /dev/null 2>&1
    display_message_result "Freezing kubernetes tools version"

}

# =============================================================================
# NAME: common_config
# DESC: install the kubernetes commands like kubeadm and kubectl, then configure 
#       host to support kubernetes node requierments
# =============================================================================

function common_config() {

    common_install

    display_section "Configure system"
    swapoff -a
    display_message_result "Disabling swap in this session"
    sed  -i  '/swap/d' /etc/fstab 
    display_message_result "Disabling swap in this file /etc/fstab"

    modprobe overlay
    display_message_result "Enabling module overlay"
    modprobe br_netfilter
    display_message_result "Enabling module br_netfilter"

    cat >>/etc/modules-load.d/containerd.conf <<EOF
overlay
br_netfilter
EOF
    display_message_result "Enabling module load for containerd"


    apt install -y containerd.io kubelet kubeadm kubectl > /dev/null 2>&1
    display_message_result "Installing containerd & kubernetes tools"

    apt-mark hold kubelet kubeadm kubectl > /dev/null 2>&1
    display_message_result "Freezing kubernetes tools version"

    containerd config default > /etc/containerd/config.toml
    display_message_result "Configuring containerd 1#2"
    sed -i 's/SystemdCgroup \= false/SystemdCgroup \= true/g' /etc/containerd/config.toml
    display_message_result "Configuring containerd 2#2"

    systemctl restart containerd
    display_message_result "Restarting containerd"
    systemctl enable containerd
    display_message_result "Enabling containerd"

    cat >>/etc/sysctl.d/kubernetes.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF
    display_message_result "Configuring network for kubernetes"

    sysctl --system > /dev/null 2>&1
    display_message_result "Applying system configuration"

    swapoff -a
}


# =============================================================================
# NAME: configure_master
# DESC: configure a master node
# =============================================================================
# $1 : mode (alone or multi or single)
# =============================================================================
function configure_master() {
    display_section "Configure kubernetes"
    kube_status=""
    if [ -f /etc/kubernetes/admin.conf ];
    then
        kube_status=$(kubectl --kubeconfig /etc/kubernetes/admin.conf get nodes 2> /dev/null|grep "$(hostname)")   
    fi
    if [ -n "${kube_status}" ];
    then
        display_message "Master node already exists" "OK"
    else   
        if [ "${KUBE_FIRST_MASTER_FLAG}" == "1" ];
        then
            cat << EOF > ./kubeadm-config.yaml
---
apiVersion: kubeadm.k8s.io/v1beta3
kind: ClusterConfiguration
networking:
    podSubnet: "${KUBE_NETWORK_CIDR}"
EOF
            if [ "$1" == "multi" ];
            then
            cat << EOF >> ./kubeadm-config.yaml
kubernetesVersion: stable
apiServer:
  certSANs:
  - ${KUBE_ADDRESS}
controlPlaneEndpoint: "${KUBE_ADDRESS}"
EOF
            fi
            systemctl restart kubelet

            kubeadm init --config=./kubeadm-config.yaml  >> "$LOG_FILE" 2>&1

            display_message_result "Starting master node"

            rm -f kubeadm-config.yaml

            mkdir -p "$HOME/.kube"
            cp -i /etc/kubernetes/admin.conf "$HOME/.kube/config"
            chown "$(id -u):$(id -g)" "$HOME/.kube/config"
            display_message_result "Writting kubernetes config file to $HOME/.kube/config"

            NET_URL=""
            case "${KUBE_NETWORK_TYPE}" in
                "flannel") NET_URL="https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml";;
                *)  display_message "Unsupported network type - switching to default (flannel)" "WARN";
                    NET_URL="https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml";;
            esac

            if [ -n  "${NET_URL}" ];
            then
                kubectl apply -f "${NET_URL}" >> "$LOG_FILE" 2>&1
                display_message_result "Loading network configuration into cluster"
            fi

            if [ "$1" == "alone" ];
            then
               kubectl taint node $(hostname) node-role.kubernetes.io/control-plane:NoSchedule- > /dev/null 2>&1

               display_message_result "Allowing pods on master because of standalone node"
               
	       # waiting for master Ready
               display_message "Waiting for node $(hostname) condition=Ready during timeout=600s" "INFO"
               kubectl wait --for=condition=Ready node $(hostname) --all --timeout=600s > /dev/null
	       
	       # check if node is Ready
	       is_node_ready "$(hostname)"
	       if [ "$?" -eq 0 ]; then
        		display_message "Your cluster is Ready" "OK"
               else
                        display_message "Your cluster is not Ready" "KO"
               fi

	       # ensure default account created
	       ensure_default_account_created

	       # run a pod test
	       test_pod_helloworld
            fi
            generate_config_archive

        else
            display_message "Next master" "INFO"

            load_config_archive

            kubeadm join "${KUBE_API_URL}" --token "${KUBE_MASTER_TOKEN}" --discovery-token-ca-cert-hash "${KUBE_DISCOVERY_HASH}" --control-plane > /dev/null 2>&1
            display_message_result "Master joining cluster"

            mkdir -p "$HOME/.kube"
            cp -i /etc/kubernetes/admin.conf "$HOME/.kube/config"
            chown "$(id -u):$(id -g)" "$HOME/.kube/config"
            display_message_result "Writting kubernetes config file to $HOME/.kube/config"
        fi            
    fi
}







# =============================================================================
# NAME: status_master
# DESC: read master status
# =============================================================================
function status_master() {   
    node_status=$(kubectl get nodes 2> /dev/null|grep "$(hostname)")
    if [ -n "${node_status}" ];
    then
        echo "installed"
    else
        echo "not installed"
    fi
}


# =============================================================================
# NAME: test_pod_helloworld
# DESC: run pod pod-helloworld.yml as test file
# =============================================================================
function test_pod_helloworld() {
  # create hello yaml file
   cat >pod-helloworld.yml <<EOF
apiVersion: v1
kind: Pod
metadata:
  name: pod-helloworld
spec:
  containers:
  - name: container-helloworld
    image: alpine
    command: ["/bin/sh"]
    args: ["-c", "echo hello world; sleep infinity"]
  restartPolicy: OnFailure
EOF
  # create pod helloworld
  kubectl delete --grace-period=1 -f pod-helloworld.yml > /dev/null 2>/dev/null
  kubectl create -f pod-helloworld.yml > /dev/null
  display_message_result "create pod-helloworld"
  # todo check if Ready=false is correct
  # try --for=condition=Completed has failed
  #
  # debug command
  # kubectl describe pod/pod-helloworld |grep Condition -A 5
  # Conditions:
  # Type              Status
  # Initialized       True
  # Ready             False
  # ContainersReady   False
  # PodScheduled      True
  #
  # wait for main lifecycle
  # from https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/ 
  # wait for PodScheduled
  #kubectl wait --for=condition=PodScheduled    pod/pod-helloworld
  #kubectl wait --for=condition=Initialized     pod/pod-helloworld
  #kubectl wait --for=condition=Ready=False    pod/pod-helloworld
  kubectl wait --for=condition=Ready pod/pod-helloworld > /dev/null
  hello=$(kubectl logs --pod-running-timeout=20s pod/pod-helloworld |grep "hello")
  display_message_result "pod-helloworld says $hello"
  kubectl delete --grace-period=1 -f pod-helloworld.yml > /dev/null
  display_message_result "delete pod-helloworld"
}

function ensure_default_account_created() {
  # The default account is known to take a while to appear; see
  #  https://github.com/kubernetes/kubernetes/issues/66689
  i="0"
  while [ $i -lt 10 ]
  do
    kubectl -n default get serviceaccount default -o name > /dev/null
    if [ "$?" -eq 0 ];
    then
        display_message "default account service account is created" "OK"
	break
    else
	i=$[$i+1]
        display_message " retry $i/10 default account service account is net yet created, sleeping for 5s" "INFO"
        sleep 5
    fi
  done  
}



# =============================================================================
# NAME: is_node_ready
# DESC: return 0 if $1 node name is Ready
# =============================================================================
# $1 name of the node
# =============================================================================
function is_node_ready() {
  # filter to all nodes where name $1 .items[?(@.metadata.name==\"$1\")]
  # read .status.conditions[] where type=Ready and return status value
  # if status is True then node is Ready
  is_ready=$(kubectl get node -o=jsonpath="{range .items[?(@.metadata.name==\""$1"\")]}{.status.conditions[?(@.type==\"Ready\")].status}")
  if [ "$is_ready" = "True" ]; then
          return 0
  else
          return 1
  fi
}



# =============================================================================
# NAME: decode_km_token
# DESC: extract content from km_token into context
# =============================================================================
# $1 : km_token
# =============================================================================
function decode_km_token() {
    KUBE_KM_TOKEN="$1"
    if [ -z "${KUBE_KM_TOKEN}" ];
    then
        display_message "--km-token is blank" "ERROR"
        exit 1
    fi
    decoded_km_token=$(echo "${KUBE_KM_TOKEN}"|base64 -d 2> /dev/null)
    display_message_result "Decoding km-token"


    KUBE_ADDRESS=$(echo "${decoded_km_token}"|cut -d ',' -f 1)
    KUBE_API_URL="${KUBE_ADDRESS}"

    display_message_result "Extracting API url and port"
    if [ -z "${KUBE_ADDRESS}" ];
    then
        display_message "--km-token not well formed: api address not present" "ERROR"
        exit 1
    fi

    KUBE_MASTER_TOKEN=$(echo "${decoded_km_token}"|cut -d ',' -f 2)
    display_message_result "Extracting join token"
    if [ -z "${KUBE_MASTER_TOKEN}" ];
    then
        display_message "--km-token not well formed: join token not present" "ERROR"
        exit 1
    fi

    KUBE_DISCOVERY_HASH=$(echo "${decoded_km_token}"|cut -d ',' -f 3)
    display_message_result "Extracting discovery hash"
    if [ -z "${KUBE_DISCOVERY_HASH}" ];
    then
        display_message "--km-token not well formed: discover hash not present" "ERROR"
        exit 1
    fi
}

# =============================================================================
# NAME: install_nginx
# DESC: install nginx and configure it as load balancer
# =============================================================================
# $1 : master list
# $2 : worker list
# =============================================================================
function install_nginx_instance() {
    display_section "Installing Nginx >> $(hostname)"
    apt update  > /dev/null 2>&1
    display_message_result "Updating package repository"
    apt install -y nginx ufw > /dev/null 2>&1
    display_message_result "Installing base needed packages"
    ufw allow 'Nginx Full' > /dev/null 2>&1
    display_message_result "Allow port 'Nginx Full' in firewall"
    ufw allow 'Nginx HTTP' > /dev/null 2>&1
    display_message_result "Allow port 'Nginx HTTP' in firewall"
    ufw allow 'Nginx HTTPS' > /dev/null 2>&1
    display_message_result "Allow port 'Nginx HTTPS' in firewall"

    mkdir -p /etc/nginx/tcpconf.d
    cat << EOF > /etc/nginx/tcpconf.d/kubernetes.conf
stream {
  upstream kubernetes {
      $(echo -e $1)
  }
   upstream kubernetes_https {
      $(echo -e $2)
  }
  server {
      listen 6443;
      proxy_pass kubernetes;
   }
     server {
      listen 443;
      proxy_pass kubernetes_https;
   }
}
EOF
    display_message_result "Creating Nginx LB configuration file"
    if ! grep -q tcpconf.d /etc/nginx/nginx.conf; 
    then
        echo 'include /etc/nginx/tcpconf.d/*;' >> /etc/nginx/nginx.conf
        display_message_result "Loading Nginx LB configuration file in default configuration"
    fi
    systemctl stop haproxy 2> /dev/null||true
    systemctl restart nginx
    display_message_result "Restarting Nginx and loading LB configuration"
}



# =============================================================================
# NAME: install_nginx_servers
# DESC: install nginx servers and configure them as load balancer
# =============================================================================
# $1 : nginx server list
# $2 : master nodes list
# $3 : worker nodes list
# =============================================================================
function install_nginx_servers() {
    display_section "Installing Nginx servers list"
    NODE_LIST_ARG=""
    while IFS= read -r CURRENT_MASTER;
    do
        NODE_LIST_ARG="${NODE_LIST_ARG} --master ${CURRENT_MASTER}:${KUBE_PORT}"
    done <<< "$2"

    while IFS= read -r CURRENT_WORKER;
    do
        NODE_LIST_ARG="${NODE_LIST_ARG} --worker ${CURRENT_WORKER}:443"
    done <<< "$3"

    while IFS= read -r CURRENT_NGINX; do

        upload_tools "${CURRENT_MASTER}" "${SSH_USER}" "${SSH_PASS}" "${SSH_KEY}"
        display_message_result "Pushing commands"
        ssh_command "${CURRENT_NGINX}" "sudo ./klb --apply --type nginx ${NODE_LIST_ARG}" "${SSH_USER}" "${SSH_PASS}" "${SSH_KEY}"
        display_message_result "Deploying nginx load-balancer"

    done <<< "$1"

}



# =============================================================================
# NAME: load_config_archive
# DESC: load archive containing masters certificats & others files needs
# =============================================================================
function load_config_archive() {
    display_section "Configuration archive >> $(hostname)"
    if [ -f ./kube-config.tgz ];
    then
        mkdir -p /etc/kubernetes/pki/etcd
        display_message_result "Creating directory structure"

        tar -xvzf ./kube-config.tgz -C / > /dev/null
        display_message_result "Extracting configuration archive"
    else
        display_message "Can't find archive file in the current directory" "KO"
        exit 1
    fi
}

# =============================================================================
# NAME: generate_config_archive
# DESC: generate archive containing masters certificats & others files needs
# =============================================================================
function generate_config_archive() {
    display_section "Configuration archive"
    rm -f ./kube-config.tgz
    tar -cvzf ./kube-config.tgz /etc/kubernetes/pki/ca.crt \
        /etc/kubernetes/pki/ca.key \
        /etc/kubernetes/pki/sa.key \
        /etc/kubernetes/pki/sa.pub \
        /etc/kubernetes/pki/front-proxy-ca.crt \
        /etc/kubernetes/pki/front-proxy-ca.key \
        /etc/kubernetes/pki/etcd/ca.crt \
        /etc/kubernetes/pki/etcd/ca.key \
        /etc/kubernetes/admin.conf > /dev/null 2>&1
    display_message_result "Generating config archive"
}