alpine-overlay/kubezero/zdt-base/common.sh

# We built on top of tiny-cloud
. /lib/tiny-cloud/common

IMDS_ENDPOINT="169.254.169.254"
. /lib/tiny-cloud/cloud/"$CLOUD"/imds

_imds() {
    wget --quiet --timeout 1 --output-document - \
        --header "$(_imds_header)" \
        "http://$IMDS_ENDPOINT/$IMDS_URI/$1$IMDS_QUERY"
}

# Todo: This should go into a yaml file
query_imds() {
  MAC=$(_imds meta-data/mac)
  AVAILABILITY_ZONE=$(_imds meta-data/placement/availability-zone)
  REGION=$(echo ${AVAILABILITY_ZONE} | sed "s/[a-z]$//")
  INSTANCE_ID=$(_imds meta-data/instance-id)

  cat <<EOF >> /var/lib/cloud/meta-data
AVAILABILITY_ZONE=$AVAILABILITY_ZONE
REGION=$REGION
INSTANCE_ID=$INSTANCE_ID
IP_ADDRESS=$(_imds meta-data/local-ipv4)
PUBLIC_IP_ADDRESS=$(_imds meta-data/public-ipv4 || true)
DEFAULT_GW_INTERFACE=$(ip -o route get 8.8.8.8 | awk '{print $5}')
MAC=$MAC
VPC_CIDR_RANGE=$(_imds meta-data/network/interfaces/macs/${MAC}/vpc-ipv4-cidr-block)
SUBNET=$(_imds meta-data/network/interfaces/macs/${MAC}/subnet-ipv4-cidr-block)
_META_HOSTNAME=$(_imds meta-data/hostname)
DOMAIN_NAME=\${_META_HOSTNAME#*.}
AWS_ACCOUNT_ID=$(_imds meta-data/network/interfaces/macs/${MAC}/owner-id)
INSTANCE_LIFE_CYCLE=$(_imds meta-data/instance-life-cycle)
INSTANCE_TYPE=$(_imds meta-data/instance-type)
EOF
}

# Todo: This should go into a yaml file
get_tags() {
  # via metadata AWS restricts tags to NOT have " " or "/" ;-(
  # Replace all /:.- with _ for valid variable names
  for key in $(_imds meta-data/tags/instance); do
    value="$(_imds meta-data/tags/instance/$key)"
    key=$(echo ${key//[\/:.-]/_} | tr '[:lower:]' '[:upper:]') 
    echo "$key=\"$value\"" >> /var/lib/cloud/meta-data
  done
  #while read _key value; do
  #  key=$(echo ${_key//[\/:.-]/_} | tr '[:lower:]' '[:upper:]') 
  #  echo "$key=\"$value\"" >> /var/lib/cloud/meta-data
  #done < <(aws ec2 describe-tags --filters "Name=resource-id,Values=${INSTANCE_ID}" --query 'Tags[*].[Key,Value]' --region $REGION --output text)
}

# extract user-data args and cloud meta-data into /var/lib/cloud/meta-data
get_meta_data() {
  if [ ! -f /var/lib/cloud/meta-data ]; then
    echo '#!/bin/bash' > /var/lib/cloud/meta-data

    query_imds
    get_tags
  fi

  if [ ! -f /etc/cloudbender.conf ]; then
    bash /var/lib/cloud/user-data extract_parameters
  fi
}

import_meta_data() {
  . /etc/cloudbender.conf
  . /var/lib/cloud/meta-data

  export AWS_DEFAULT_REGION=$REGION
  export AWS_DEFAULT_OUTPUT=text

  # some basic logic
  if [ "$DEBUG" == "None" -o "$DEBUG" == "False" ]; then
    unset DEBUG

    LAUNCH_HOOK="CloudBenderLaunchHook"
  fi

  # Workaround for current CFN ASG_<parameter> hack
  _key=$(echo $AWS_CLOUDFORMATION_LOGICAL_ID | tr '[:lower:]' '[:upper:]') 
  [ -n "$(eval echo \$${_key}_CUSTOMHOSTNAME)" ] && CUSTOMHOSTNAME="$(eval echo \$${_key}_CUSTOMHOSTNAME)"
  [ -n "$(eval echo \$${_key}_VOLUMES)" ] && VOLUMES="$(eval echo \$${_key}_VOLUMES)"

  return 0
}

# setup_instance, various OS tweaks impossible to do via AMI baking
setup_instance() {
    # create machine-id to emulate systemd
  [ -f /etc/machine-id ] || uuidgen > /etc/machine-id

  # add and mount bpf file system
  add_once /etc/fstab "bpffs       /sys/fs/bpf    bpf      rw,nosuid,nodev,noexec,relatime,mode=700 0 0" 
  mount -a

  # Ensure certain mounts are shared to run containers later, eg. cilium, falco
  mount --make-shared /sys/fs/cgroup
  mount --make-shared /sys/fs/bpf
  mount --make-shared /sys

  add_once /etc/hosts "${IP_ADDRESS} ${_META_HOSTNAME} ${HOSTNAME}"

  # Set system wide default region for boto3
  echo "export AWS_DEFAULT_REGION=$REGION" > /etc/profile.d/aws.sh

  # workaround for dhcpcd / openresolv to omit search domain if equal to domain breaking DNS resolution of shortnames for eg. etcd and kube-apiserver
  add_once /etc/resolv.conf "search $DOMAIN_NAME"

  case "$CLOUD" in
    aws)
      setup_sns_alarms
      ;;
    *)
      ewarn "Unsupported Cloud: $CLOUD"
      # return 1
      ;;
  esac
}

################ 
# IAM SSH KEYS #
################ 
configure_sshd() {
  # Change Listen port
  local port=${SSHPORT:-"22"}
  [ -w /etc/ssh/sshd_config ] && sed -i -e 's/^[\s#]*Port\s.*/Port '$port'/' /etc/ssh/sshd_config

  case "$CLOUD" in
    aws)
      # on AWS call IAM for allowed groups and actual keys
      local group=${SSHKEYIAMGROUP:-""}
      local role=${SSHKEYIAMROLE:-"arn:aws:iam::000000000000:role/Undefined"}
      [ $role == "arn:aws:iam::000000000000:role/Undefined" ] && role=""

      if [ -n "$group" ]; then
        # Configure SSHD
        sed -i -e 's,^[\s#]*AuthorizedKeysCommand\s.*,AuthorizedKeysCommand /usr/sbin/get_iam_sshkeys.py --user %u --group '$group' --iamRole "'$role'",' /etc/ssh/sshd_config
        sed -i -e 's,^[\s#]*AuthorizedKeysCommandUser\s.*,AuthorizedKeysCommandUser nobody,' /etc/ssh/sshd_config

        ebegin "added $group to SSH admin keys"
      fi
      ;;
    *)
      ewarn "Unsupported Cloud: $CLOUD"
      # return 1
      ;;
  esac
}


# Persist host keys
# has to run before sshd starts up first time !
persistent_sshd_hostkeys() {
  # Top level is artifact to be able to limit the SSM IAM permissions
  local ssm_path=$1
  local key_types="ecdsa ed25519 rsa"

  # try to get none existing host keys from SSM
  RET=0
  for key in $key_types; do
    if [ ! -f /etc/ssh/ssh_host_${key}_key.pub -a ! -f /etc/ssh/ssh_host_${key}_key ]; then
    (aws ssm get-parameters --names "${ssm_path}/host_${key}.tgz" --with-decryption --query 'Parameters[0].Value' | base64 -d | tar xzf - --directory=/ 1>/dev/null 2>&1) \
      && log -t user-data info "Restored ssh_host_${key}_key from SSM" || RET=1
    fi
  done

  # Update keys if any key couldn't be restored from SSM
  if [ $RET -eq 1 ]; then
    # generate any missing keys
    ssh-keygen -A

    for key in $key_types; do
      if [ -r /etc/ssh/ssh_host_${key}_key -a -r /etc/ssh/ssh_host_${key}_key.pub ]; then
        (aws ssm put-parameter --name "${ssm_path}/host_${key}.tgz" --type SecureString --value \
            "$(tar czf - /etc/ssh/ssh_host_${key}_key /etc/ssh/ssh_host_${key}_key.pub | base64)" --overwrite) \
          && log -t user-data info "Uploaded ssh_host_${key}_key to SSM"
      fi
    done
  fi
}

# either plain custom hostname or
# - `unique:<format_string>` eg. `uniq:kube-worker-{:02}` -> kube-worker-01
# - `myownip: <prefix>` eg. `myip: nodegroup-` -> nodegroup-1.2.3.4
set_hostname() {
  local custom_hostname=$(echo $1 | awk -F. '{ print $1 }')

  if [ -n "$custom_hostname" ]; then
    if [[ "$custom_hostname" == unique:* ]]; then
      new_hostname=$(uniq_hostname.py $AWS_EC2LAUNCHTEMPLATE_ID $INSTANCE_ID ${custom_hostname##unique:})

    elif [[ "$custom_hostname" == myownip:* ]]; then
      local _ip=$(echo $IP_ADDRESS | sed -e 's/\./-/g')
      new_hostname=$(echo "${custom_hostname##myownip:}$_ip")

    else
      new_hostname=$custom_hostname
    fi

    FQDN="${new_hostname}.${DOMAIN_NAME}"
    echo ${new_hostname} > /etc/hostname

    hostname $new_hostname
    export HOSTNAME=$new_hostname

    # add new hostname to hosts
    add_once /etc/hosts "${IP_ADDRESS} ${FQDN} ${new_hostname}"

    log -t user-data info "Hostname updated to ${new_hostname}."

    # hup syslog to update loghost macro
    /etc/init.d/syslog-ng reload

    # update Route53 entry for VPC internal FQDN
    route53.py --fqdn $FQDN --record $IP_ADDRESS

    # update our Name Tag to FQDN or PrivateDNSName to allow easy indentification in the AWS UI
    aws ec2 create-tags --resources $INSTANCE_ID --tags Key=Name,Value=$FQDN
  else
    aws ec2 create-tags --resources $INSTANCE_ID --tags Key=Name,Value=${HOSTNAME}.${REGION}.compute.internal
  fi
}

# various early volume functions
attach_ebs() {
  local volId="$1"
  local device="$2"

  local tries=30
  while true; do
    _json="$(aws ec2 describe-volumes --volume-ids $volId --region $REGION --output json)"
    rc=$?; [ $rc -ne 0 ] && return $rc

    vol_status=$(echo "$_json" | jq -r .Volumes[].State)
    attachedId=$(echo "$_json" | jq -r .Volumes[].Attachments[].InstanceId)

    [ "$attachedId" = "$INSTANCE_ID" ] && break

    if [ "$vol_status" = "available" ]; then
      aws ec2 attach-volume --volume-id "$volId" --instance-id "$INSTANCE_ID" --region "$REGION" --device "$device" > /dev/null
      rc=$?; [ $rc -ne 0 ] && return $rc
      break
    fi

    # if attached but not to us -> detach
    if [ "$vol_status" = "in-use" ]; then
      aws ec2 detach-volume --volume-id "$volId" --region "$REGION" --force
      rc=$?; [ $rc -ne 0 ] && return $rc
    fi

    ((tries=tries-1))
    [ $tries -eq 0 ] && return 1
    sleep 5
  done
}

_parse_volume() {
  # Todo: proper checks once all is yaml
  # For now just replace ':'
  echo $1 | sed -e 's/:/ /g'
}

# mount optional remote volumes
mount_volumes() {
  local volumes="$1"

  for vol in $volumes; do
    # Todo: check volume type and call matching func
    read volType volId volDevice volPath < <(_parse_volume $vol)

    [ "$volType" != "ebs" ] && { echo "Unknown volume type $volType"; break; }
    attach_ebs $volId $volDevice
    rc=$?
    [ $rc -ne 0 ] && { ewarn "error trying to attach $volId"; break; }

    # wait for the block device to become available
    while true; do
      mdev -s
      test -b $volDevice && break
      sleep 1
    done

    # check volume for existing filesystem
    type=$(file -Lbs $volDevice)
    if [[ "$type" =~ "XFS filesystem" ]]; then
      xfs_repair $volDevice >/dev/null 2>&1
    else
      mkfs.xfs -qf $volDevice >/dev/null
    fi

    # mount
    mkdir -p $volPath
    mount -t xfs -o noatime $volDevice $volPath

    ebegin "mounting $volDevice at $volPath"
  done
}

unmount_volumes() {
  local volumes="$1"

  for vol in $volumes; do
    read volType volId volDevice volPath < <(_parse_volume $vol)

    umount $volPath && aws ec2 detach-volume --volume-id "$volId" --instance-id $INSTANCE_ID --region $REGION > /dev/null
  done
}

# msg used for sns event, last one wins
msg() { MSG="$@"; log -t user-data info "$@"; }

# boolean flags
is_enabled() {
  local flag=$(echo "$1" | tr '[:upper:]' '[:lower:]')

  [ "$flag" == 1 -o "$flag" == "true" ] && return 0
  [ "$flag" == 0 -o "$flag" == "false" -o -z "$flag" ] && return 1

  log -t user-data warn "Unknown value for boolean option: $flag - assuming False"
  return 1
}

# Generic retry command wrapper, incl. timeout of 30s
# $1 = number of tries; 0 = forever
# $2 = number of seconds to sleep between tries
# $@ actual command
retry() {
  local tries=$1
  local waitfor=$2
  shift 2
  while true; do
    # Only use timeout of $1 is an executable, call directly if function
    type -tf $1 >/dev/null && { timeout 30 $@ && return; } || { $@ && return; }
    ((tries=tries-1)) || true
    [ $tries -eq 0 ] && return 1
    sleep $waitfor
  done
}

add_swap() {
  [ -f /.swapfile ] || { dd if=/dev/zero of=/.swapfile bs=1M count=$1 && chmod 600 /.swapfile && mkswap /.swapfile && swapon /.swapfile; }
  grep -q "/.swapfile" /etc/fstab || echo "/.swapfile none swap sw 0 0" >> /etc/fstab
  sysctl -w vm.swappiness=10
}

# Get SSM secure string base64 decoded
# $0 SSM_PATH, value to stdout
get_secret() {
  aws ssm get-parameter --name ${1,,} --with-decryption --query 'Parameter.Value' | base64 -d
}

# Store values as base64 on SSM
# $0 SSM_PATH VALUE
put_secret() {
  aws ssm put-parameter --name ${1,,} --type SecureString --value "$(echo "$2" | base64 -w0)" --overwrite
}

# Gets existing passphrase or creates new passphrase and stores it
init_passphrase() {
  local _URL=$1
  local _PPFILE=$2

  # If secret already exists noop
  [ -f $_PPFILE ] && return 0

  get_secret $_URL > $_PPFILE && chmod 600 $_PPFILE || \
    { xxd -l16 -p /dev/random > $_PPFILE; chmod 600 $_PPFILE; put_secret $_URL "$(cat $_PPFILE)"; }
}

asg_heartbeat() {
  [ -n "$LAUNCH_HOOK" ] && aws autoscaling record-lifecycle-action-heartbeat --instance-id $INSTANCE_ID --lifecycle-hook-name $LAUNCH_HOOK --auto-scaling-group-name $AWS_AUTOSCALING_GROUPNAME || true
}

setup_sns_alarms() {
  # store SNS message json template
  cat <<EOF > /var/lib/cloud/sns_alarm.json
{
  "Source": "CloudBender",
  "AWSAccountId": "$AWS_ACCOUNT_ID",
  "Region": "$REGION",
  "Artifact": "$ARTIFACT",
  "Asg": "$AWS_AUTOSCALING_GROUPNAME",
  "Instance": "$INSTANCE_ID",
  "ip": "$IP_ADDRESS"
}
EOF

  cat <<'EOF' > /var/lib/cloud/sns_alarm.sh
#!/bin/bash

SUBJECT=$1
MSG=$2
LEVEL=${3:-Info}
ATTACHMENT=${4:-""}
EMOJI=${5:-""}
EOF
  if [ -n "$ALARMSNSARN" ]; then
    cat <<EOF >> /var/lib/cloud/sns_alarm.sh
jq -M --arg subject "\$SUBJECT" --arg level "\$LEVEL" --arg msg "\$MSG" --arg attachment "\$ATTACHMENT" --arg emoji "\$EMOJI" --arg hostname "\$HOSTNAME" '.Subject = \$subject | .Level = \$level | .Message = \$msg | .Attachment = \$attachment | .Emoji = \$emoji | .Hostname = \$hostname' < /var/lib/cloud/sns_alarm.json | sed -e 's/\\\\\\\\/\\\\/g' > /tmp/sns.json
aws sns publish --region ${REGION} --target-arn $ALARMSNSARN --message file:///tmp/sns.json
EOF
  fi

  chmod +x /var/lib/cloud/sns_alarm.sh
}

exit_trap() {
  set +e
  trap - ERR EXIT
  local ERR_CODE=$1
  local ERR_LINE="$2"
  local ERR_FUNC="$3"
  local ERR_CMD="$4"

  if [ $ERR_CODE -ne 0 ]; then
    CFN_STATUS="FAILURE"
    RESULT="ABANDON"
  else
    CFN_STATUS="SUCCESS"
    RESULT="CONTINUE"
  fi

  # Add SNS events on demand
  if [ -n "$ALARMSNSARN" ]; then
    if [ $ERR_CODE -ne 0 ]; then
      LEVEL="Error"
      SUBJECT="Error during cloud-init."
      if [ $ERR_LINE -ne 1 ]; then
        MSG="$ERR_CMD failed in $ERR_FUNC at $ERR_LINE. Return: $ERR_CODE"
        ATTACHMENT="$(pr -tn $0 | tail -n+$((ERR_LINE - 3)) | head -n7)"
      else
        MSG="$ERR_CMD"
      fi

      if [ -n "$DEBUG" ]; then
        SUBJECT="$SUBJECT Instance kept running for debug."
      else
        SUBJECT="$SUBJECT Instance terminated by ASG lifecycle hook."
      fi
    else
      LEVEL="Info"
      SUBJECT="ZDT Alpine Instance launched."
    fi

    if [ -z "${DISABLECLOUDBENDERSNSSCALINGEVENTS}" ] || [ "$LEVEL" != "Info" ]; then
      /var/lib/cloud/sns_alarm.sh "$SUBJECT" "$MSG" "$LEVEL" "$ATTACHMENT"
    fi

    # Disable scaling events during shutdown
    [ -n "${DISABLECLOUDBENDERSNSSCALINGEVENTS}" ] && echo "DISABLE_SCALING_EVENTS=1" >> /etc/cloudbender.conf
  fi

  [ -n "$LAUNCH_HOOK" ] && aws autoscaling complete-lifecycle-action --lifecycle-action-result $RESULT --instance-id $INSTANCE_ID --lifecycle-hook-name $LAUNCH_HOOK --auto-scaling-group-name ${AWS_AUTOSCALING_GROUPNAME} || true

  if [ -n "${AWS_CLOUDFORMATION_LOGICAL_ID}" ]; then
    aws cloudformation signal-resource --stack-name ${AWS_CLOUDFORMATION_STACK_NAME} --logical-resource-id ${AWS_CLOUDFORMATION_LOGICAL_ID} --unique-id ${INSTANCE_ID} --status ${CFN_STATUS}
  fi

  # timestamp being done
  end_uptime=$(awk '{print $1}' < /proc/uptime)
  log -t user-data info "Exiting user-data. Duration: $(echo "$end_uptime-$start_uptime" | bc) seconds"

  # Shutdown / poweroff if we ran into error and not DEBUG
  [ $ERR_CODE -ne 0 -a -z "$DEBUG" ] && poweroff

  exit 0
}

### S3 based locking
MUTEX=mutex
MUTEX_OWNER=$HOSTNAME
MUTEX_TIMEOUT=600

release_lock() {
  local S3LOCK=$1

  rm -f $MUTEX
  aws s3 rm $S3LOCK
}

# Lock not timed out and we own it: 0
# Lock not timed out and someone else owns it: 1
# Lock timed out: 2
verify_lock() {
  local S3LOCK=$1

  aws s3 cp $S3LOCK $MUTEX
  _host=$(grep "MUTEX_OWNER=" $MUTEX | sed -e 's/MUTEX_OWNER=//')
  _time=$(grep "MUTEX_TIME=" $MUTEX | sed -e 's/MUTEX_TIME=//')

  # Check for timestamp and timeout
  let timepassed=$(date -u +%s)-$_time
  [ $timepassed -gt $MUTEX_TIMEOUT ] && return 2

  [ "$_host" == "$MUTEX_OWNER" ] && return 0
  return 1
}

aquire_lock() {
  local S3LOCK=$1

  echo "MUTEX_OWNER=${MUTEX_OWNER}" > $MUTEX
  echo "MUTEX_TIME=$(date -u +%s)" >> $MUTEX
  aws s3 cp $MUTEX $S3LOCK

  # verify we actually got the lock
  sleep 2
  verify_lock $S3LOCK
}

check_lock() {
  local S3LOCK=$1

  aws s3 ls $S3LOCK && rc=$? || rc=$?

  # No LOCK ? -> get it !
  if [ $rc -ne 0 ]; then
    aquire_lock $S3LOCK

  else
    verify_lock $S3LOCK && rc=$? || rc=$?

    # Lock timeout -> we get it
    if [ $rc -eq 2 ]; then
      aquire_lock $S3LOCK

    # we already own it
    elif [ $rc -eq 0 ]; then
      return 0

    # someone else has a valid lock
    else
      return 1
    fi
  fi
}

# All things networking
enable_ip_forwarding() {
  modprobe nf_conntrack

  cat <<EOF > /etc/sysctl.d/40-ip-forward.conf
net.ipv4.ip_forward=1
net.ipv4.ip_local_port_range = 1024 65535
net.ipv4.conf.all.send_redirects=0
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.all.accept_redirects = 0
net.ipv6.conf.default.forwarding = 1
net.ipv6.conf.all.forwarding = 1
net.netfilter.nf_conntrack_max = 524288
EOF
  sysctl -p /etc/sysctl.d/40-ip-forward.conf
}

enable_iptables() {
  rc-update add iptables
  /etc/init.d/iptables save
}


register_service_dns() {
  if [ -n "$DNSZONE" -a -n "$SERVICENAME" ]; then
    _IP=${PUBLIC_IP_ADDRESS:-$IP_ADDRESS}
    [ -n "SERVICEPRIVATE" ] && _IP=$IP_ADDRESS
    route53.py --fqdn "${SERVICENAME}.${DNSZONE}" --record $_IP

    # Register shutdown hook to remove DNS entry on terminate
    cat <<EOF >> /etc/local.d/route53.stop
echo "Deleting Route53 record for ${SERVICENAME}.${DNSZONE}" >> /tmp/shutdown.log
route53.py --delete --fqdn "${SERVICENAME}.${DNSZONE}" --record ${PUBLIC_IP_ADDRESS:-$IP_ADDRESS}
EOF
    chmod +x /etc/local.d/route53.stop

    # Short cut our public IP to private one to allow talking to our own service name
    add_once /etc/hosts "${IP_ADDRESS} ${SERVICENAME}.${DNSZONE}"
  fi
}


# associate EIP
# return 0 if we attached an EIP
# return 1 if we the public IP did NOT change or other error
associate_eip() {
  local instance_id=$1
  local eip=$(echo $2 | sed -e 's/\/32//' | grep -E -o "(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)") || true
  local current_instance

  if [ -n "$eip" ]; then
    if [ "$eip" != "0.0.0.0" ]; then
      read eip_alloc_id eip_assoc_id current_instance  < <(aws ec2 describe-addresses --public-ips $eip --query 'Addresses[*].[AllocationId,AssociationId,InstanceId]' || true)

      # If we already own and have the EIP attached -> done
      [ "$instance_id" == "$current_instance" ] && return

      if [ ! -z "$eip_alloc_id" ]; then
        if [[ "$eip_assoc_id" =~ ^eipassoc- ]]; then
          log -t user-data info "EIP $eip already associated via Association ID ${eip_assoc_id}. Disassociating."
          retry 3 10 aws ec2 disassociate-address --association-id $eip_assoc_id
        fi

        log -t user-data info "Associating Elastic IP $eip via Allocation ID $eip_alloc_id with Instance $instance_id"
        aws ec2 associate-address --no-allow-reassociation --instance-id $instance_id --allocation-id $eip_alloc_id
        return

      else
        log -t user-data warn "Elastic IP $eip address not found."
      fi
    else
      log -t user-data info "0.0.0.0 requested, keeping AWS assigned IP."
    fi
  else
    log -t user-data debug "Invalid or no ElasticIP defined. Skip"
  fi

  return 1
}




# Accept incoming traffic for everything
disable_source_dest_check() {
  aws ec2 modify-instance-attribute --instance-id ${INSTANCE_ID} --source-dest-check "{\"Value\": false}"
}


# Register ourself at route tables
register_routes() {
  local rtb_id_list="$1"
  local route_cidr="$2"

  for cidr in ${route_cidr//,/ }; do
    if [ "$cidr" != "$VPC_CIDR_RANGE" ]; then
      for rt in ${rtb_id_list//,/ }; do
        if [[ "$rt" =~ ^rtb-[a-f0-9]*$ ]]; then
          aws ec2 create-route --route-table-id $rt --destination-cidr-block "${cidr}" --instance-id ${INSTANCE_ID} || \
          aws ec2 replace-route --route-table-id $rt --destination-cidr-block "${cidr}" --instance-id ${INSTANCE_ID}
        else
          log -t user-data warn "Invalid Route Table ID: $rt"
        fi
      done
    fi
  done
}


setup_nat() {
  local mode=$1

  # Masquerade all outgoing traffic
  iptables -t nat -A POSTROUTING -o $DEFAULT_GW_INTERFACE -s ${VPC_CIDR_RANGE} -j MASQUERADE
}


setup_fluentbit() {
  local key="cloudbender"
  local host="$1"

  if [[ "$host" =~ "@" ]]; then
    key=${host%%@*}
    host=${host##*@}
  fi

  # add some AWS metadata
  cat <<EOF > /etc/fluent-bit/metadata.conf
[FILTER]
    Name record_modifier
    Match *
    Record source.ip $IP_ADDRESS
    Record source.instance_id $INSTANCE_ID
    Record source.region $REGION
    Record source.account $AWS_ACCOUNT_ID
    Record source.conglomerate $CONGLOMERATE
    Record source.artifact $ARTIFACT
EOF

  # Configure output
  cat <<EOF > /etc/fluent-bit/output.conf
[OUTPUT]
    Match *
    Name forward
    Host $host
    Port 24224
    Shared_Key $key
    tls on
    Send_options true
    Require_ack_response true
EOF
  
  LOG_FILES=$LOGGING_FILES

  ## TODO:
  # Add parameter parsing for custom logfile tailing
}