#!/bin/bash

# Dependencies:
#
# - functions
# - ``STACK_USER`` must be defined

# stack.sh
# --------
# - install_k8s

# The following variables are assumed to be defined by certain functions:
#
# - ``http_proxy`` ``https_proxy`` ``no_proxy``

# Save trace setting
_XTRACE_DOCKER=$(set +o | grep xtrace)
set +o xtrace


# Defaults
# --------

K8S_TOKEN=${K8S_TOKEN:-""}
K8S_API_SERVER_IP=${K8S_API_SERVER_IP:-$SERVICE_HOST}
K8S_NODE_IP=${K8S_NODE_IP:-$HOST_IP}
K8S_API_SERVER_PORT=${K8S_API_SERVER_PORT:-6443}
K8S_POD_NETWORK_CIDR=${K8S_POD_NETWORK_CIDR:-10.244.0.0/16}
K8S_SERVICE_NETWORK_CIDR=${K8S_SERVICE_NETWORK_CIDR:-10.96.0.0/12}
K8S_VERSION=${K8S_VERSION:-1.14.1-00}
K8S_NETWORK_ADDON=${K8S_NETWORK_ADDON:-flannel}

# Functions
# ---------

function is_k8s_enabled {
    [[ ,${ENABLED_SERVICES} =~ ,"k8s-" ]] && return 0
    return 1
}

function install_kubeadm {
    if is_ubuntu; then
        apt_get install apt-transport-https curl
        curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
        sudo add-apt-repository -y \
            "deb https://apt.kubernetes.io/ kubernetes-xenial main"
        REPOS_UPDATED=False apt_get_update
        apt_get install kubelet=$K8S_VERSION kubeadm=$K8S_VERSION kubectl=$K8S_VERSION
        sudo apt-mark hold kubelet kubeadm kubectl
        # NOTE(hongbin): This work-around an issue that kubelet pick a wrong
        # IP address if the node has multiple network interfaces.
        # See https://github.com/kubernetes/kubeadm/issues/203
        echo "KUBELET_EXTRA_ARGS=--node-ip=$K8S_NODE_IP" | sudo tee -a /etc/default/kubelet
        sudo systemctl daemon-reload && sudo systemctl restart kubelet
    else
        (>&2 echo "WARNING: kubeadm installation is not supported in this distribution.")
    fi
}

function kubeadm_init {
    local kubeadm_config_file
    kubeadm_config_file=$(mktemp)
    cat <<EOF | sudo tee $kubeadm_config_file >/dev/null
apiVersion: kubeadm.k8s.io/v1beta1
kind: ClusterConfiguration
etcd:
  external:
    endpoints:
    - "http://${SERVICE_HOST}:${ETCD_PORT}"
networking:
  podSubnet: "${K8S_POD_NETWORK_CIDR}"
  serviceSubnet: "${K8S_SERVICE_NETWORK_CIDR}"
---
apiVersion: kubeadm.k8s.io/v1beta1
bootstrapTokens:
- token: "${K8S_TOKEN}"
  ttl: 0s
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: "${K8S_API_SERVER_IP}"
  bindPort: ${K8S_API_SERVER_PORT}
---
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
failSwapOn: false
EOF
    sudo kubeadm init --config $kubeadm_config_file --ignore-preflight-errors Swap

    local kube_config_file=$HOME/.kube/config
    sudo mkdir -p $(dirname ${kube_config_file})
    sudo cp /etc/kubernetes/admin.conf $kube_config_file
    safe_chown $STACK_USER:$STACK_USER $kube_config_file

    if [[ "$K8S_NETWORK_ADDON" == "flannel" ]]; then
        kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/a70459be0084506e4ec919aa1c114638878db11b/Documentation/kube-flannel.yml
    fi
}

function kubeadm_join {
    local kubeadm_config_file
    kubeadm_config_file=$(mktemp)
    cat <<EOF | sudo tee $kubeadm_config_file >/dev/null
apiVersion: kubeadm.k8s.io/v1beta1
kind: JoinConfiguration
discovery:
  bootstrapToken:
    apiServerEndpoint: "${K8S_API_SERVER_IP}:${K8S_API_SERVER_PORT}"
    token: "${K8S_TOKEN}"
    unsafeSkipCAVerification: true
  tlsBootstrapToken: "${K8S_TOKEN}"
---
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
failSwapOn: false
EOF
    sudo kubeadm join --config $kubeadm_config_file --ignore-preflight-errors Swap
}

function start_collect_logs {
    wait_for_kube_service 180 component=kube-controller-manager
    wait_for_kube_service 60 component=kube-apiserver
    wait_for_kube_service 30 component=kube-scheduler
    wait_for_kube_service 30 k8s-app=kube-proxy
    run_process kube-controller-manager "/usr/bin/kubectl logs -n kube-system -f -l component=kube-controller-manager"
    run_process kube-apiserver "/usr/bin/kubectl logs -n kube-system -f -l component=kube-apiserver"
    run_process kube-scheduler "/usr/bin/kubectl logs -n kube-system -f -l component=kube-scheduler"
    run_process kube-proxy "/usr/bin/kubectl logs -n kube-system -f -l k8s-app=kube-proxy"
}

function wait_for_kube_service {
    local timeout=$1
    local selector=$2
    local rval=0
    time_start "wait_for_service"
    timeout $timeout bash -x <<EOF || rval=$?
        NAME=""
        while [[ "\$NAME" == "" ]]; do
            sleep 1
            NAME=\$(kubectl wait --for=condition=Ready pod -n kube-system -l $selector -o name)
        done
EOF
    time_stop "wait_for_service"
    # Figure out what's happening on platforms where this doesn't work
    if [[ "$rval" != 0 ]]; then
        echo "Didn't find kube service after $timeout seconds"
        kubectl get pods -n kube-system -l $selector
    fi
    return $rval
}

function kubeadm_reset {
    sudo kubeadm reset --force
}

# Restore xtrace
$_XTRACE_DOCKER