From ec2d07eedc295467cf3f4c15f6659f4cc60df7e1 Mon Sep 17 00:00:00 2001 From: Brian Ojeda <9335829+sgtoj@users.noreply.github.com> Date: Wed, 9 Aug 2023 19:00:42 +0000 Subject: [PATCH] feat: add submodule to create ssh-tunnels --- modules/teleport-db-login/README.md | 2 - modules/teleport-db-login/main.tf | 2 +- modules/teleport-ssh-tunnel/README.md | 57 ++++ .../teleport-ssh-tunnel/assets/tunneler.sh | 164 +++++++++++ modules/teleport-ssh-tunnel/context.tf | 277 ++++++++++++++++++ modules/teleport-ssh-tunnel/main.tf | 14 + modules/teleport-ssh-tunnel/output.tf | 9 + modules/teleport-ssh-tunnel/variables.tf | 19 ++ 8 files changed, 541 insertions(+), 3 deletions(-) create mode 100644 modules/teleport-ssh-tunnel/README.md create mode 100644 modules/teleport-ssh-tunnel/assets/tunneler.sh create mode 100755 modules/teleport-ssh-tunnel/context.tf create mode 100755 modules/teleport-ssh-tunnel/main.tf create mode 100644 modules/teleport-ssh-tunnel/output.tf create mode 100644 modules/teleport-ssh-tunnel/variables.tf diff --git a/modules/teleport-db-login/README.md b/modules/teleport-db-login/README.md index c90db9c..8770609 100644 --- a/modules/teleport-db-login/README.md +++ b/modules/teleport-db-login/README.md @@ -6,8 +6,6 @@ for a secure and reusable way to handle database authentication. ## Overview -This submodule performs the following actions: - - Retrieves and sets the database connection information such as host, port, SSL CA, SSL certificate, and SSL key. - Executes the `db-login` command of Teleport's CLI to authenticate with the diff --git a/modules/teleport-db-login/main.tf b/modules/teleport-db-login/main.tf index 5ce8ea3..f41cf29 100755 --- a/modules/teleport-db-login/main.tf +++ b/modules/teleport-db-login/main.tf @@ -9,7 +9,7 @@ locals { data "external" "db_connection_info" { program = [ - "${path.module}/externals/tsh.sh", + "${path.module}/assets/tsh.sh", "db-login", "stdin" ] diff --git a/modules/teleport-ssh-tunnel/README.md b/modules/teleport-ssh-tunnel/README.md new file mode 100644 index 0000000..37ca482 --- /dev/null +++ b/modules/teleport-ssh-tunnel/README.md @@ -0,0 +1,57 @@ +# Terraform SSH Tunnel + +This Terraform submodule creates an SSH tunnel using Teleport. It encapsulates +the logic needed to securely connect to a target host through a specific gateway +within a Teleport cluster. + +## Overview + +- Sets up an SSH tunnel via Teleport. +- Utilizes the Teleport cluster and gateway to route the tunnel. +- Connects to a specified target host and port. + +## Usage + +```hcl +module "teleport_ssh_tunnel" { + source = "cruxstack/teleport-cluster/aws//modules/teleport-ssh-tunnel" + version = "x.x.x" + + target_cluster = "your-target-cluster.teleport.example.com" + terraform_gateway = "name-of-terraform-gateway" + target_host = "your-target-database.example.com" + target_host = "5439" # example for redshift +} + +# configure redshift (eg, `brainly/redshift`) provider to connect to the db +provider "redshift" { + host = module.teleport_ssh_tunnel.host + port = module.teleport_ssh_tunnel.port + database = "" + username = "" + password = "" +} +``` + +## Requirements + +- Terraform host requires `tsh` and `jq` to be installed. +- Teleport cluster must be preconfigured with the target databases. +- Active login in session is required before using this module. + - eg, `tsh login --proxy=teleport.example.com --user=` + +## Inputs + +| Name | Description | Type | Default | Required | +|---------------------|--------------------------|----------|---------|:--------:| +| `terraform_cluster` | Teleport cluster domain. | `string` | n/a | yes | +| `terraform_gateway` | Teleport gateway. | `string` | n/a | yes | +| `target_host` | Target host. | `string` | n/a | yes | +| `target_port` | Target port. | `number` | n/a | yes | + +## Outputs + +| Name | Description | +|--------|------------------| +| `host` | SSH tunnel host. | +| `port` | SSH tunnel port. | diff --git a/modules/teleport-ssh-tunnel/assets/tunneler.sh b/modules/teleport-ssh-tunnel/assets/tunneler.sh new file mode 100644 index 0000000..defbd55 --- /dev/null +++ b/modules/teleport-ssh-tunnel/assets/tunneler.sh @@ -0,0 +1,164 @@ +#!/usr/bin/env bash +# shellcheck disable=SC2317 + +SCRIPT_ROOT="$( cd "$( dirname "${BASH_SOURCE[0]}" )/" &> /dev/null && pwd )" +SCRIPT_EXIT_CODE=0 + +TUNNEL_TIMEOUT=20m + +# ---------------------------------------------------------------------- fns --- + +function check_process_exists { + ps -p "${1}" >/dev/null 2>&1 && echo "true" || echo "false" +} + +function get_random_ephemeral_port() { + LOWER_BOUND=49152 + UPPER_BOUND=65000 + while true; do + CANDIDATE_PORT=$(( LOWER_BOUND + (RANDOM % (UPPER_BOUND - LOWER_BOUND)) )) + if ! (echo -n "" >/dev/tcp/127.0.0.1/"${CANDIDATE_PORT}") >/dev/null 2>&1; then + # return port number if open + echo "${CANDIDATE_PORT}" && break + fi + done +} + +function get_gateway_address() { + TELEPORT_CLUSTER=${1:?} + TELEPORT_GATEWAY_NAME=${2:?} + + NODE_HOST=$( + tsh ls --cluster "${TELEPORT_CLUSTER}" \ + --query="labels[\"service\"] == \"${TELEPORT_GATEWAY_NAME}\"" \ + --format names | head -n 1 + ) + echo "root@${NODE_HOST}" +} + +function open_tunnel() { + TSH_CLUSTER_NAME=${1:?} + TUNNEL_LOCAL_PORT=${2:?} + TUNNEL_TARGET_HOST=${3:?} + TUNNEL_TARGET_PORT=${4:?} + TUNNEL_GATEWAY_ADDRESS=${5:?} + + tsh ssh --cluster "${TSH_CLUSTER_NAME}" \ + -N -L "${TUNNEL_LOCAL_PORT}:${TUNNEL_TARGET_HOST}:${TUNNEL_TARGET_PORT}" \ + "${TUNNEL_GATEWAY_ADDRESS}" +} + +function open_background_tunnel() { + TSH_CLUSTER_NAME=${1:?} + TUNNEL_LOCAL_PORT=${2:?} + TUNNEL_TARGET_HOST=${3:?} + TUNNEL_TARGET_PORT=${4:?} + TUNNEL_GATEWAY_ADDRESS=${5:?} + + tsh ssh --cluster "${TSH_CLUSTER_NAME}" \ + -N -L "${TUNNEL_LOCAL_PORT}:${TUNNEL_TARGET_HOST}:${TUNNEL_TARGET_PORT}" \ + "${TUNNEL_GATEWAY_ADDRESS}" & + TUNNEL_PID=$! + + sleep 0 + + while true ; do + if [[ "$(check_process_exists "${TUNNEL_PID}")" == "false" ]] ; then + echo "ERROR: tsh ssh tunnel process (${TUNNEL_PID}) failed" >&2 + exit 1 + fi + sleep 1 + done + + kill "${TUNNEL_PID}" +} + +function open_background_tunnel_with_timeout() { + TSH_CLUSTER_NAME=${1:?} + TUNNEL_LOCAL_PORT=${2:?} + TUNNEL_TARGET_HOST=${3:?} + TUNNEL_TARGET_PORT=${4:?} + TUNNEL_GATEWAY_ADDRESS=${5:?} + TUNNEL_TIMEOUT=${6:-$TUNNEL_TIMEOUT} + + PARENT_PROCESS_ID="$(ps -p "${PPID}" -o "ppid=")" + + CHILD_PROCRESS_LOG=$(mktemp) + nohup timeout "${TUNNEL_TIMEOUT}" \ + "${SCRIPT_ROOT}/tunneler.sh" \ + "open_background_tunnel" \ + "${TSH_CLUSTER_NAME}" \ + "${TUNNEL_LOCAL_PORT}" \ + "${TUNNEL_TARGET_HOST}" \ + "${TUNNEL_TARGET_PORT}" \ + "${TUNNEL_GATEWAY_ADDRESS}" \ + "${PARENT_PROCESS_ID}" \ + <&- >&- 2>"${CHILD_PROCRESS_LOG}" & + CHILD_PROCESS_ID=$! + + sleep 3 + + # throw error if tunnel (child process) is not active + if [[ "$(check_process_exists "${CHILD_PROCESS_ID}")" == "false" ]]; then + echo "ERROR: child process (${CHILD_PROCESS_ID}) failed" >&2 + cat "${CHILD_PROCRESS_LOG}" >&2 + SCRIPT_EXIT_CODE=1 + fi +} + +# --------------------------------------------------------------------- main --- + +function create() { + TELEPORT_CLUSTER=${1:?} + TELEPORT_GATEWAY_NAME=${2:?} + TUNNEL_TARGET_HOST=${3:?} + TUNNEL_TARGET_PORT=${4:?} + + TUNNEL_LOCAL_PORT=$(get_random_ephemeral_port) + TUNNEL_GATEWAY_ADDRESS=$(get_gateway_address "${TELEPORT_CLUSTER}" "${TELEPORT_GATEWAY_NAME}") + + open_background_tunnel_with_timeout \ + "${TELEPORT_CLUSTER}" \ + "${TUNNEL_LOCAL_PORT}" \ + "${TUNNEL_TARGET_HOST}" \ + "${TUNNEL_TARGET_PORT}" \ + "${TUNNEL_GATEWAY_ADDRESS}" + + echo "${TUNNEL_LOCAL_PORT}" +} + +# ------------------------------------------------------------------- script --- + +if [[ "${1}" == "create" && "${2}" == "stdin" ]]; then + + # handler if input is stdin (e.g. from terraform) + + INPUT="$(dd 2>/dev/null)" + TELEPORT_CLUSTER=$(echo "${INPUT}" | jq -r .teleport_cluster) + TELEPORT_GATEWAY_NAME=$(echo "${INPUT}" | jq -r .teleport_gateway_name) + TUNNEL_TARGET_HOST=$(echo "${INPUT}" | jq -r .target_host) + TUNNEL_TARGET_PORT=$(echo "${INPUT}" | jq -r .target_port) + + TUNNEL_LOCAL_PORT=$(create "${TELEPORT_CLUSTER}" "${TELEPORT_GATEWAY_NAME}" "${TUNNEL_TARGET_HOST}" "${TUNNEL_TARGET_PORT}") + echo "{\"host\":\"localhost\",\"port\":\"${TUNNEL_LOCAL_PORT}\"}" + +elif [[ "${1}" == "create" ]]; then + + # handler for normal cli calls + + shift + + TUNNEL_LOCAL_PORT=$(create "${@}") + echo "localhost:${TUNNEL_LOCAL_PORT}" + +else + + COMMAND=${1:?} + COMMAND=${COMMAND//-/_} # convert dashes to unders + shift + + "${COMMAND}" "${@}" + +fi + +exit "${SCRIPT_EXIT_CODE}" diff --git a/modules/teleport-ssh-tunnel/context.tf b/modules/teleport-ssh-tunnel/context.tf new file mode 100755 index 0000000..873244c --- /dev/null +++ b/modules/teleport-ssh-tunnel/context.tf @@ -0,0 +1,277 @@ +# +# ONLY EDIT THIS FILE IN github.com/cloudposse/terraform-null-label +# All other instances of this file should be a copy of that one +# +# +# Copy this file from https://github.com/cloudposse/terraform-null-label/blob/master/exports/context.tf +# and then place it in your Terraform module to automatically get +# Cloud Posse's standard configuration inputs suitable for passing +# to Cloud Posse modules. +# +# curl -sL https://raw.githubusercontent.com/cloudposse/terraform-null-label/master/exports/context.tf -o context.tf +# +# Modules should access the whole context as `module.this.context` +# to get the input variables with nulls for defaults, +# for example `context = module.this.context`, +# and access individual variables as `module.this.`, +# with final values filled in. +# +# For example, when using defaults, `module.this.context.delimiter` +# will be null, and `module.this.delimiter` will be `-` (hyphen). +# + +module "this" { + source = "cloudposse/label/null" + version = "0.25.0" # requires Terraform >= 0.13.0 + + enabled = var.enabled + namespace = var.namespace + tenant = var.tenant + environment = var.environment + stage = var.stage + name = var.name + delimiter = var.delimiter + attributes = var.attributes + tags = var.tags + additional_tag_map = var.additional_tag_map + label_order = var.label_order + regex_replace_chars = var.regex_replace_chars + id_length_limit = var.id_length_limit + label_key_case = var.label_key_case + label_value_case = var.label_value_case + descriptor_formats = var.descriptor_formats + labels_as_tags = var.labels_as_tags + + context = var.context +} + +# Copy contents of cloudposse/terraform-null-label/variables.tf here + +variable "context" { + type = any + default = { + enabled = true + namespace = null + tenant = null + environment = null + stage = null + name = null + delimiter = null + attributes = [] + tags = {} + additional_tag_map = {} + regex_replace_chars = null + label_order = [] + id_length_limit = null + label_key_case = null + label_value_case = null + descriptor_formats = {} + # Note: we have to use [] instead of null for unset lists due to + # https://github.com/hashicorp/terraform/issues/28137 + # which was not fixed until Terraform 1.0.0, + # but we want the default to be all the labels in `label_order` + # and we want users to be able to prevent all tag generation + # by setting `labels_as_tags` to `[]`, so we need + # a different sentinel to indicate "default" + labels_as_tags = ["unset"] + } + description = <<-EOT + Single object for setting entire context at once. + See description of individual variables for details. + Leave string and numeric variables as `null` to use default value. + Individual variable settings (non-null) override settings in context object, + except for attributes, tags, and additional_tag_map, which are merged. + EOT + + validation { + condition = lookup(var.context, "label_key_case", null) == null ? true : contains(["lower", "title", "upper"], var.context["label_key_case"]) + error_message = "Allowed values: `lower`, `title`, `upper`." + } + + validation { + condition = lookup(var.context, "label_value_case", null) == null ? true : contains(["lower", "title", "upper", "none"], var.context["label_value_case"]) + error_message = "Allowed values: `lower`, `title`, `upper`, `none`." + } +} + +variable "enabled" { + type = bool + default = null + description = "Set to false to prevent the module from creating any resources" +} + +variable "namespace" { + type = string + default = null + description = "ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique" +} + +variable "tenant" { + type = string + default = null + description = "ID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is for" +} + +variable "environment" { + type = string + default = null + description = "ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'" +} + +variable "stage" { + type = string + default = null + description = "ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'" +} + +variable "name" { + type = string + default = null + description = <<-EOT + ID element. Usually the component or solution name, e.g. 'app' or 'jenkins'. + This is the only ID element not also included as a `tag`. + The "name" tag is set to the full `id` string. There is no tag with the value of the `name` input. + EOT +} + +variable "delimiter" { + type = string + default = null + description = <<-EOT + Delimiter to be used between ID elements. + Defaults to `-` (hyphen). Set to `""` to use no delimiter at all. + EOT +} + +variable "attributes" { + type = list(string) + default = [] + description = <<-EOT + ID element. Additional attributes (e.g. `workers` or `cluster`) to add to `id`, + in the order they appear in the list. New attributes are appended to the + end of the list. The elements of the list are joined by the `delimiter` + and treated as a single ID element. + EOT +} + +variable "labels_as_tags" { + type = set(string) + default = ["default"] + description = <<-EOT + Set of labels (ID elements) to include as tags in the `tags` output. + Default is to include all labels. + Tags with empty values will not be included in the `tags` output. + Set to `[]` to suppress all generated tags. + **Notes:** + The value of the `name` tag, if included, will be the `id`, not the `name`. + Unlike other `null-label` inputs, the initial setting of `labels_as_tags` cannot be + changed in later chained modules. Attempts to change it will be silently ignored. + EOT +} + +variable "tags" { + type = map(string) + default = {} + description = <<-EOT + Additional tags (e.g. `{'BusinessUnit': 'XYZ'}`). + Neither the tag keys nor the tag values will be modified by this module. + EOT +} + +variable "additional_tag_map" { + type = map(string) + default = {} + description = <<-EOT + Additional key-value pairs to add to each map in `tags_as_list_of_maps`. Not added to `tags` or `id`. + This is for some rare cases where resources want additional configuration of tags + and therefore take a list of maps with tag key, value, and additional configuration. + EOT +} + +variable "label_order" { + type = list(string) + default = null + description = <<-EOT + The order in which the labels (ID elements) appear in the `id`. + Defaults to ["namespace", "environment", "stage", "name", "attributes"]. + You can omit any of the 6 labels ("tenant" is the 6th), but at least one must be present. + EOT +} + +variable "regex_replace_chars" { + type = string + default = null + description = <<-EOT + Terraform regular expression (regex) string. + Characters matching the regex will be removed from the ID elements. + If not set, `"/[^a-zA-Z0-9-]/"` is used to remove all characters other than hyphens, letters and digits. + EOT +} + +variable "id_length_limit" { + type = number + default = null + description = <<-EOT + Limit `id` to this many characters (minimum 6). + Set to `0` for unlimited length. + Set to `null` for keep the existing setting, which defaults to `0`. + Does not affect `id_full`. + EOT + validation { + condition = var.id_length_limit == null ? true : var.id_length_limit >= 6 || var.id_length_limit == 0 + error_message = "The id_length_limit must be >= 6 if supplied (not null), or 0 for unlimited length." + } +} + +variable "label_key_case" { + type = string + default = null + description = <<-EOT + Controls the letter case of the `tags` keys (label names) for tags generated by this module. + Does not affect keys of tags passed in via the `tags` input. + Possible values: `lower`, `title`, `upper`. + Default value: `title`. + EOT + + validation { + condition = var.label_key_case == null ? true : contains(["lower", "title", "upper"], var.label_key_case) + error_message = "Allowed values: `lower`, `title`, `upper`." + } +} + +variable "label_value_case" { + type = string + default = null + description = <<-EOT + Controls the letter case of ID elements (labels) as included in `id`, + set as tag values, and output by this module individually. + Does not affect values of tags passed in via the `tags` input. + Possible values: `lower`, `title`, `upper` and `none` (no transformation). + Set this to `title` and set `delimiter` to `""` to yield Pascal Case IDs. + Default value: `lower`. + EOT + + validation { + condition = var.label_value_case == null ? true : contains(["lower", "title", "upper", "none"], var.label_value_case) + error_message = "Allowed values: `lower`, `title`, `upper`, `none`." + } +} + +variable "descriptor_formats" { + type = any + default = {} + description = <<-EOT + Describe additional descriptors to be output in the `descriptors` output map. + Map of maps. Keys are names of descriptors. Values are maps of the form + `{ + format = string + labels = list(string) + }` + (Type is `any` so the map values can later be enhanced to provide additional options.) + `format` is a Terraform format string to be passed to the `format()` function. + `labels` is a list of labels, in order, to pass to `format()` function. + Label values will be normalized before being passed to `format()` so they will be + identical to how they appear in `id`. + Default is `{}` (`descriptors` output will be empty). + EOT +} \ No newline at end of file diff --git a/modules/teleport-ssh-tunnel/main.tf b/modules/teleport-ssh-tunnel/main.tf new file mode 100755 index 0000000..c77ae84 --- /dev/null +++ b/modules/teleport-ssh-tunnel/main.tf @@ -0,0 +1,14 @@ +data "external" "tunnel" { + program = [ + "${path.module}/assets/tunneler.sh", + "create", + "stdin" + ] + + query = { + terraform_cluster = var.terraform_cluster + terraform_gateway = var.terraform_gateway + target_host = var.target_host + target_port = var.target_port + } +} diff --git a/modules/teleport-ssh-tunnel/output.tf b/modules/teleport-ssh-tunnel/output.tf new file mode 100644 index 0000000..b2a9d62 --- /dev/null +++ b/modules/teleport-ssh-tunnel/output.tf @@ -0,0 +1,9 @@ +output "host" { + value = module.this.enabled ? data.external.tunnel.result.host : "" + description = "SSH tunnel host." +} + +output "port" { + value = module.this.enabled ? data.external.tunnel.result.port : "" + description = "SSH tunnel port." +} diff --git a/modules/teleport-ssh-tunnel/variables.tf b/modules/teleport-ssh-tunnel/variables.tf new file mode 100644 index 0000000..e889804 --- /dev/null +++ b/modules/teleport-ssh-tunnel/variables.tf @@ -0,0 +1,19 @@ +variable "terraform_cluster" { + type = string + description = "Teleport cluster domain." +} + +variable "terraform_gateway" { + type = string + description = "Teleport gateway." +} + +variable "target_host" { + type = string + description = "Target host." +} + +variable "target_port" { + type = number + description = "Target port." +}