TeamSpeak server query snapshot helper script

teamspeak-snapshot.sh

#!/bin/bash

set -e
set -u
# set -x # during dev

printUsage() {
  cat <<EOF >/dev/stderr

Usage: $0 [protocol://][user@]host[:port] (password) action [-s sid] [-f snapshot_file]

    protocol    "raw", "ssh" - Protocol used to connect to the server query. (Default: "raw")

                <password> can only be provided as an argument when using the RAW protocol.

    user        Server query user. (Default: "serveradmin")
    port        Port of the RAW (telnet) or SSH server query.

                Default: 10011 (raw), 10022 (ssh)

Actions:

    create      Create a server snapshot of virtual server with id <sid>. (Default: 1)
                Without a <snapshot_file> specified, STDOUT is used.

    deploy      Deploy a server snapshot to virtual server with id <sid>. (Default: 1)
                Without a <snapshot_file> specified, the script reads from STDIN.

                Options: [-keepfiles]

                  -keepfiles    The channels that exist on the virtualserver and the
                                backup keep will have their files preserved.
EOF
}

readFlagParameter() {
  local input_string=$(cat -)

  local match=$(echo "$input_string" | grep -o -E "(^|[^-])\\-$1\>")
  # if the flag is not specified: everything ok
  if [[ -z "$match" ]]; then
    echo ""
    return 0
  fi

  local parameter=$(echo "$input_string" | grep -E -o "\\-$1 [^- ]+" | sed -E "s/-$1 (.+)/\\1/")
  # when flag is specified, but no value is provided: error
  if [[ -z "$parameter" ]]; then
    printUsage
    exit 1
  fi

  echo "$parameter"
  return 0
}

CONNECT_LOCATION=$(echo "$1" | sed -E 's/(([a-z]+):\/\/)?((.+)@)?([^:]+)(:([0-9]+))?/\2 \4 \5 \7/')

CHECK_CONNECT_LOCATION=$(echo "$CONNECT_LOCATION" | grep -o -E "^[a-z]* [^:/]* [^:]+ [0-9]*$" || true)
if [[ -z "$CHECK_CONNECT_LOCATION" ]]; then
  (
    echo "Invalid URL: $1"
    echo
  ) >/dev/stderr

  printUsage
  exit 1
fi

PROTOCOL=$(echo "$CONNECT_LOCATION" | cut -d' ' -f 1)
PROTOCOL=${PROTOCOL:-"raw"}

USER=$(echo "$CONNECT_LOCATION" | cut -d' ' -f 2)
USER=${USER:-"serveradmin"}

HOST=$(echo "$CONNECT_LOCATION" | cut -d' ' -f 3)
PORT=$(echo "$CONNECT_LOCATION" | cut -d' ' -f 4)

case "$PROTOCOL" in
raw)
  if [ $# -lt 3 ]; then
    printUsage
    exit 1
  fi

  PORT=${PORT:-"10011"}

  PASSWORD=$2
  ACTION=$3

  OPTION_FLAGS=$(echo "$@" | cut -d' ' -f 4-)
  ;;

ssh)
  if [ $# -lt 2 ]; then
    printUsage
    exit 1
  fi

  PORT=${PORT:-"10022"}

  ACTION=$2

  OPTION_FLAGS=$(echo "$@" | cut -d' ' -f 3-)
  ;;

*)
  (
    echo "No such protocol: $PROTOCOL"
    echo
  ) >/dev/stderr
  printUsage
  exit 1
  ;;
esac

SID=$(echo "$OPTION_FLAGS" | readFlagParameter 's')
SID=${SID:-1}

SNAPSHOT_FILE=$(echo "$OPTION_FLAGS" | readFlagParameter 'f')

KEEPFILES=$(echo "$OPTION_FLAGS" | grep -o -E '(^|[^-])\-keepfiles\>' | tr -d ' ')

case "$ACTION" in
create)
  if [[ -n "$SNAPSHOT_FILE" ]] && [[ -f "$SNAPSHOT_FILE" ]]; then
    echo "A snapshot file '$SNAPSHOT_FILE' already exists. An overwrite would delete the old snapshot!" >/dev/stderr
    echo "Remove the old snapshot file manually or choose a different name." >/dev/stderr
    exit 3
  fi

  QUERY_COMMAND=$(
    echo "use $SID"
    [[ "$PROTOCOL" == "raw" ]] && echo "login $USER $PASSWORD"
    echo "serversnapshotcreate"
    echo "quit"
  )

  case "$PROTOCOL" in
  raw)
    QUERY_RESPONSE=$(
      echo "$QUERY_COMMAND" |
        nc $HOST $PORT |
        tr -d '\r'
    )
    ;;

  ssh)
    QUERY_RESPONSE=$(
      echo "$QUERY_COMMAND" |
        ssh $USER@$HOST -p$PORT |
        tr -d '\r'
    )
    ;;
  esac

  if [[ -z "$QUERY_RESPONSE" ]]; then
    echo "Server did not respond." >/dev/stderr
    exit 6
  fi

  # "grep ... || true": prevent non-zero exit code from grep when no match
  QUERY_ERRORS=$(echo "$QUERY_RESPONSE" | grep "^error" | grep -v "id=0" || true)

  if [[ -n "$QUERY_ERRORS" ]]; then
    (
      echo "Server query returned with errors:"
      echo
      echo "$QUERY_ERRORS"
    ) >/dev/stderr
    exit 4
  fi

  SNAPSHOT_DATA=$(echo "$QUERY_RESPONSE" | grep -E '^version=\d+ data=.*$' || true)
  if [[ -z "$SNAPSHOT_DATA" ]]; then
    (
      echo "No snapshot data received!"
      echo
      echo "Got following reponse:"
      echo
      echo "$QUERY_RESPONSE"
    ) >/dev/stderr
    exit 5
  fi

  echo "$SNAPSHOT_DATA" >${SNAPSHOT_FILE:-/dev/stdout}
  ;;

deploy)
  if [[ -n "$SNAPSHOT_FILE" ]] && [[ ! -f "$SNAPSHOT_FILE" ]]; then
    echo "Snapshot file '$SNAPSHOT_FILE' is not a regular file or does not exist." >/dev/stderr
    exit 2
  fi

  # prevent reading from STDIN on interactive shell
  if [ -t 0 ] && [[ -z "$SNAPSHOT_FILE" ]]; then
    # interactive
    (
      echo "Not reading from STDIN on an interactive shell."
      echo
      echo "Use -f to specify the snapshot file."
    ) >/dev/stderr
    exit 7
  fi

  QUERY_COMMAND=$(
    echo "use $SID"
    [[ "$PROTOCOL" == "raw" ]] && echo "login $USER $PASSWORD"
    echo -n "serversnapshotdeploy $KEEPFILES "
    cat ${SNAPSHOT_FILE:-/dev/stdin}
    echo
    echo "quit"
  )

  case "$PROTOCOL" in
  raw)
    QUERY_RESPONSE=$(
      echo "$QUERY_COMMAND" |
        nc $HOST $PORT |
        tr -d '\r'
    )
    ;;

  ssh)
    QUERY_RESPONSE=$(
      echo "$QUERY_COMMAND" |
        ssh $USER@$HOST -p$PORT |
        tr -d '\r'
    )
    ;;
  esac

  if [[ -z "$QUERY_RESPONSE" ]]; then
    echo "Server did not respond." >/dev/stderr
    exit 6
  fi

  # "grep ... || true": prevent non-zero exit code from grep when no match
  QUERY_ERRORS=$(echo "$QUERY_RESPONSE" | grep "^error" | grep -v "id=0" || true)

  if [[ -n "$QUERY_ERRORS" ]]; then
    (
      echo "Server query returned with errors:"
      echo
      echo "$QUERY_ERRORS"
    ) >/dev/stderr
    exit 4
  fi
  ;;

*)
  printUsage
  exit 1
  ;;
esac