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| 1 | +#!/usr/bin/env bash |
| 2 | +# shellcheck disable=SC2317 |
| 3 | + |
| 4 | +SCRIPT_ROOT="$( cd "$( dirname "${BASH_SOURCE[0]}" )/" &> /dev/null && pwd )" |
| 5 | +SCRIPT_EXIT_CODE=0 |
| 6 | + |
| 7 | +TUNNEL_TIMEOUT=20m |
| 8 | + |
| 9 | +# ---------------------------------------------------------------------- fns --- |
| 10 | + |
| 11 | +function check_process_exists { |
| 12 | + ps -p "${1}" >/dev/null 2>&1 && echo "true" || echo "false" |
| 13 | +} |
| 14 | + |
| 15 | +function get_random_ephemeral_port() { |
| 16 | + LOWER_BOUND=49152 |
| 17 | + UPPER_BOUND=65000 |
| 18 | + while true; do |
| 19 | + CANDIDATE_PORT=$(( LOWER_BOUND + (RANDOM % (UPPER_BOUND - LOWER_BOUND)) )) |
| 20 | + if ! (echo -n "" >/dev/tcp/127.0.0.1/"${CANDIDATE_PORT}") >/dev/null 2>&1; then |
| 21 | + # return port number if open |
| 22 | + echo "${CANDIDATE_PORT}" && break |
| 23 | + fi |
| 24 | + done |
| 25 | +} |
| 26 | + |
| 27 | +function get_gateway_address() { |
| 28 | + TELEPORT_CLUSTER=${1:?} |
| 29 | + TELEPORT_GATEWAY_NAME=${2:?} |
| 30 | + |
| 31 | + NODE_HOST=$( |
| 32 | + tsh ls --cluster "${TELEPORT_CLUSTER}" \ |
| 33 | + --query="labels[\"service\"] == \"${TELEPORT_GATEWAY_NAME}\"" \ |
| 34 | + --format names | head -n 1 |
| 35 | + ) |
| 36 | + echo "root@${NODE_HOST}" |
| 37 | +} |
| 38 | + |
| 39 | +function open_tunnel() { |
| 40 | + TSH_CLUSTER_NAME=${1:?} |
| 41 | + TUNNEL_LOCAL_PORT=${2:?} |
| 42 | + TUNNEL_TARGET_HOST=${3:?} |
| 43 | + TUNNEL_TARGET_PORT=${4:?} |
| 44 | + TUNNEL_GATEWAY_ADDRESS=${5:?} |
| 45 | + |
| 46 | + tsh ssh --cluster "${TSH_CLUSTER_NAME}" \ |
| 47 | + -N -L "${TUNNEL_LOCAL_PORT}:${TUNNEL_TARGET_HOST}:${TUNNEL_TARGET_PORT}" \ |
| 48 | + "${TUNNEL_GATEWAY_ADDRESS}" |
| 49 | +} |
| 50 | + |
| 51 | +function open_background_tunnel() { |
| 52 | + TSH_CLUSTER_NAME=${1:?} |
| 53 | + TUNNEL_LOCAL_PORT=${2:?} |
| 54 | + TUNNEL_TARGET_HOST=${3:?} |
| 55 | + TUNNEL_TARGET_PORT=${4:?} |
| 56 | + TUNNEL_GATEWAY_ADDRESS=${5:?} |
| 57 | + |
| 58 | + tsh ssh --cluster "${TSH_CLUSTER_NAME}" \ |
| 59 | + -N -L "${TUNNEL_LOCAL_PORT}:${TUNNEL_TARGET_HOST}:${TUNNEL_TARGET_PORT}" \ |
| 60 | + "${TUNNEL_GATEWAY_ADDRESS}" & |
| 61 | + TUNNEL_PID=$! |
| 62 | + |
| 63 | + sleep 0 |
| 64 | + |
| 65 | + while true ; do |
| 66 | + if [[ "$(check_process_exists "${TUNNEL_PID}")" == "false" ]] ; then |
| 67 | + echo "ERROR: tsh ssh tunnel process (${TUNNEL_PID}) failed" >&2 |
| 68 | + exit 1 |
| 69 | + fi |
| 70 | + sleep 1 |
| 71 | + done |
| 72 | + |
| 73 | + kill "${TUNNEL_PID}" |
| 74 | +} |
| 75 | + |
| 76 | +function open_background_tunnel_with_timeout() { |
| 77 | + TSH_CLUSTER_NAME=${1:?} |
| 78 | + TUNNEL_LOCAL_PORT=${2:?} |
| 79 | + TUNNEL_TARGET_HOST=${3:?} |
| 80 | + TUNNEL_TARGET_PORT=${4:?} |
| 81 | + TUNNEL_GATEWAY_ADDRESS=${5:?} |
| 82 | + TUNNEL_TIMEOUT=${6:-$TUNNEL_TIMEOUT} |
| 83 | + |
| 84 | + PARENT_PROCESS_ID="$(ps -p "${PPID}" -o "ppid=")" |
| 85 | + |
| 86 | + CHILD_PROCRESS_LOG=$(mktemp) |
| 87 | + nohup timeout "${TUNNEL_TIMEOUT}" \ |
| 88 | + "${SCRIPT_ROOT}/tunneler.sh" \ |
| 89 | + "open_background_tunnel" \ |
| 90 | + "${TSH_CLUSTER_NAME}" \ |
| 91 | + "${TUNNEL_LOCAL_PORT}" \ |
| 92 | + "${TUNNEL_TARGET_HOST}" \ |
| 93 | + "${TUNNEL_TARGET_PORT}" \ |
| 94 | + "${TUNNEL_GATEWAY_ADDRESS}" \ |
| 95 | + "${PARENT_PROCESS_ID}" \ |
| 96 | + <&- >&- 2>"${CHILD_PROCRESS_LOG}" & |
| 97 | + CHILD_PROCESS_ID=$! |
| 98 | + |
| 99 | + sleep 3 |
| 100 | + |
| 101 | + # throw error if tunnel (child process) is not active |
| 102 | + if [[ "$(check_process_exists "${CHILD_PROCESS_ID}")" == "false" ]]; then |
| 103 | + echo "ERROR: child process (${CHILD_PROCESS_ID}) failed" >&2 |
| 104 | + cat "${CHILD_PROCRESS_LOG}" >&2 |
| 105 | + SCRIPT_EXIT_CODE=1 |
| 106 | + fi |
| 107 | +} |
| 108 | + |
| 109 | +# --------------------------------------------------------------------- main --- |
| 110 | + |
| 111 | +function create() { |
| 112 | + TELEPORT_CLUSTER=${1:?} |
| 113 | + TELEPORT_GATEWAY_NAME=${2:?} |
| 114 | + TUNNEL_TARGET_HOST=${3:?} |
| 115 | + TUNNEL_TARGET_PORT=${4:?} |
| 116 | + |
| 117 | + TUNNEL_LOCAL_PORT=$(get_random_ephemeral_port) |
| 118 | + TUNNEL_GATEWAY_ADDRESS=$(get_gateway_address "${TELEPORT_CLUSTER}" "${TELEPORT_GATEWAY_NAME}") |
| 119 | + |
| 120 | + open_background_tunnel_with_timeout \ |
| 121 | + "${TELEPORT_CLUSTER}" \ |
| 122 | + "${TUNNEL_LOCAL_PORT}" \ |
| 123 | + "${TUNNEL_TARGET_HOST}" \ |
| 124 | + "${TUNNEL_TARGET_PORT}" \ |
| 125 | + "${TUNNEL_GATEWAY_ADDRESS}" |
| 126 | + |
| 127 | + echo "${TUNNEL_LOCAL_PORT}" |
| 128 | +} |
| 129 | + |
| 130 | +# ------------------------------------------------------------------- script --- |
| 131 | + |
| 132 | +if [[ "${1}" == "create" && "${2}" == "stdin" ]]; then |
| 133 | + |
| 134 | + # handler if input is stdin (e.g. from terraform) |
| 135 | + |
| 136 | + INPUT="$(dd 2>/dev/null)" |
| 137 | + TELEPORT_CLUSTER=$(echo "${INPUT}" | jq -r .teleport_cluster) |
| 138 | + TELEPORT_GATEWAY_NAME=$(echo "${INPUT}" | jq -r .teleport_gateway_name) |
| 139 | + TUNNEL_TARGET_HOST=$(echo "${INPUT}" | jq -r .target_host) |
| 140 | + TUNNEL_TARGET_PORT=$(echo "${INPUT}" | jq -r .target_port) |
| 141 | + |
| 142 | + TUNNEL_LOCAL_PORT=$(create "${TELEPORT_CLUSTER}" "${TELEPORT_GATEWAY_NAME}" "${TUNNEL_TARGET_HOST}" "${TUNNEL_TARGET_PORT}") |
| 143 | + echo "{\"host\":\"localhost\",\"port\":\"${TUNNEL_LOCAL_PORT}\"}" |
| 144 | + |
| 145 | +elif [[ "${1}" == "create" ]]; then |
| 146 | + |
| 147 | + # handler for normal cli calls |
| 148 | + |
| 149 | + shift |
| 150 | + |
| 151 | + TUNNEL_LOCAL_PORT=$(create "${@}") |
| 152 | + echo "localhost:${TUNNEL_LOCAL_PORT}" |
| 153 | + |
| 154 | +else |
| 155 | + |
| 156 | + COMMAND=${1:?} |
| 157 | + COMMAND=${COMMAND//-/_} # convert dashes to unders |
| 158 | + shift |
| 159 | + |
| 160 | + "${COMMAND}" "${@}" |
| 161 | + |
| 162 | +fi |
| 163 | + |
| 164 | +exit "${SCRIPT_EXIT_CODE}" |
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