feat(wpcarro): Define deploy-diogenes helper

TL;DR:
- Mimmick depot's bin -> __dispatch.sh for personal utils
- Define deploy-diogenes to more tighten my feedback loop

Change-Id: I2b12a1c32a955574f5be5d4f38025bd97e9c7b77
Reviewed-on: https://cl.tvl.fyi/c/depot/+/4751
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>

users/wpcarro/.envrc

@@ -1,2 +1,3 @@
 source_up
-export WPCARRO="$REPO_ROOT/users/wpcarro"
+export PATH="${PWD}/bin:${PATH}"
+export WPCARRO="${REPO_ROOT}/users/wpcarro"

users/wpcarro/bin/__dispatch.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+# This script dispatches invocations transparently to programs instantiated from
+# Nix.
+#
+# To add a new tool, insert it into the case statement below by setting `attr`
+# to the key in nixpkgs which represents the program you want to run.
+set -ueo pipefail
+
+TARGET_TOOL=$(basename "$0")
+
+case "${TARGET_TOOL}" in
+  deploy-diogenes)
+    attr="users.wpcarro.nixos.deploy-diogenes"
+    ;;
+  *)
+    echo "The tool '${TARGET_TOOL}' is currently not installed in this repository."
+    exit 1
+    ;;
+esac
+
+result=$(nix-build --no-out-link --attr "${attr}" "${REPO_ROOT}")
+PATH="${result}/bin:$PATH"
+
+exec "${TARGET_TOOL}" "${@}"

users/wpcarro/bin/deploy-diogenes

@@ -0,0 +1 @@
+__dispatch.sh

users/wpcarro/nixos/default.nix

@@ -1,8 +1,22 @@
-{ depot, ... }:
+{ depot, pkgs, ... }:
 
 let systemFor = sys: (depot.ops.nixos.nixosFor sys).system;
 in {
   marcusSystem = systemFor depot.users.wpcarro.nixos.marcus;
+  deploy-diogenes = pkgs.writeShellScriptBin "deploy-diogenes" ''
+    set -euo pipefail
+    readonly TF_STATE_DIR=/depot/users/wpcarro/terraform
+    rm -f $TF_STATE_DIR/*.json
+    readonly STORE_PATH="$(nix-build /depot -A users.wpcarro.nixos.diogenes)"
+    cp $STORE_PATH $TF_STATE_DIR
+
+    function cleanup() {
+      rm -f "$TF_STATE_DIR/$(basename $STORE_PATH)"
+    }
+
+    trap cleanup EXIT
+    ${pkgs.terraform}/bin/terraform -chdir="$TF_STATE_DIR" apply
+  '';
 
   meta.targets = [ "marcusSystem" ];
 }