Flynn cluster login helper

flynn-login.sh

#!/bin/bash

##
# Login into any Flynn node without checking strict host key checking and run given command
# $1 - address for the cluster
# $2...n - command to run in server
##
function flynn_ssh_helper() {
    cluster_domain=$1
    ssh -oStrictHostKeyChecking=no $(dig +short $cluster_domain | head -n1) "${@:2}" 2>/dev/null
}

##
# Helper to login to flynn
# $1 - cluster name
# $2 - cluster domain
##
function flynn_login_helper() {
    export CLUSTER_NAME=$1
    export CLUSTER_DOMAIN=$2
    echo "---> Getting tls pin from $CLUSTER_DOMAIN with openssl..."
    tls_pin=$(openssl s_client -connect controller.$CLUSTER_DOMAIN:443 -servername controller.$CLUSTER_DOMAIN 2>/dev/null </dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' | openssl x509 -inform PEM -outform DER | openssl dgst -binary -sha256 | openssl base64)
    if [ -z $tls_pin ]; then
        echo "[ERROR]: Can't get tls pin from $CLUSTER_DOMAIN, is the certificate valid?"
        return 1
    fi

    echo "---> Getting password from $CLUSTER_DOMAIN with ssh..."
    dashboard_container_id=$(flynn_ssh_helper $CLUSTER_DOMAIN flynn-host ps | grep dashboard | head -n1 | cut -f1 -d ' ')
    password=$(flynn_ssh_helper $CLUSTER_DOMAIN flynn-host inspect $dashboard_container_id | grep CONTROLLER_KEY | xargs echo | cut -f2 -d ' ')

    if [ -z $password ]; then
        echo "[ERROR]: Can't get password from $CLUSTER_DOMAIN, do you have permissions to login?"
        return 1
    fi

    echo "[INFO]: Creating authentication into ~/.flynnrc for cluster $CLUSTER_NAME"
    flynn cluster add -p $tls_pin $CLUSTER_NAME $CLUSTER_DOMAIN $password --force
    RESULT=$?
    if [ $RESULT != 0 ]; then
        echo "[ERROR]: Something went wrong..."
    fi
}

if [ -z $1 ]; then
    echo "You need to provide name for the cluster as first parameter..."
    echo "usage: $0 stage stage.example.com"
    exit 1
elif [ -z $2 ]; then
    echo "You need to provide the address of the cluster as second parameter..."
    echo "usage: $0 $1 $1.example.com"
    exit 1
fi

# Set name and domain from paramaters
CLUSTER_NAME=$1
CLUSTER_DOMAIN=$2

echo "[INFO]: Setting up flynn environment..."

if ! command -v flynn >/dev/null 2>&1 flynn; then
    echo "---> installing flynn cli..."
    L=/usr/local/bin/flynn
    curl -sSL -A "`uname -sp`" https://dl.flynn.io/cli | zcat >$L && chmod +x $L
else
    echo "---> flynn binary is already installed"
fi

echo "[INFO]: Checking ssh connection..."
ssh -q -oStrictHostKeyChecking=no $(dig +short $CLUSTER_DOMAIN | head -n1) exit 2>/dev/null
RESULT=$?
if [ $RESULT != 0 ]; then
    echo "[ERROR]: Can't login with ssh, do you have access for $USER@$CLUSTER_DOMAIN?"
    exit 1
else
    echo "---> Success: SSH authentication works..."
fi

# Login to the environment
flynn_login_helper $CLUSTER_NAME $CLUSTER_DOMAIN