_scripts/cacheWarm: warm the CUE dependency cache

This adds a script that warms the CUE dependency cache, using
credentials for the central registry passed in via the
CUELANG_CUE_LOGINS environment variable.

This is primarily to solve the problem of CUE needing access to these
CUE dependencies during the Netlify build stage that's executed by
production deployments, tip deployments, and PR previews.

The trybot CI workflow is updated to call this script directly, as the
logic is identical but the sequencing is different (CI needs the cache
warmed sooner than the build.bash script is invoked).

Signed-off-by: Jonathan Matthews <[email protected]>
Change-Id: I63dacf1fe0f250a72750a9f3886ff8fb61436671
Dispatch-Trailer: {"type":"trybot","CL":1203266,"patchset":2,"ref":"refs/changes/66/1203266/2","targetBranch":"master"}

_scripts/build.bash

@@ -32,7 +32,10 @@ cd "$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )/.."
 #
 # * Locally, in development
 # * In CI, both as part of a trybot run, or on the default branch post submit
-# * In Netlify during deploy
+# * In Netlify, during deployment of:
+#   - the production site ("cuelang.org")
+#   - the site built against the tip of cue-lang/cue ("tip")
+#   - any PR preview
 #
 # Rather than declare a "fall-through" of logic, each environment is separately
 # handled with comments to make clear the logic/reasoning behind each flag value.
@@ -153,6 +156,13 @@ else
 
 fi
 
+# Fetch any CUE dependencies.
+if [[ "${NETLIFY:-}" == "true" ]]; then
+    export CUELANG_CUE_LOGINS
+    bash _scripts/cacheWarm.bash
+    export -n CUELANG_CUE_LOGINS
+fi
+
 # Build playground
 bash playground/_scripts/build.bash
 

_scripts/cacheWarm.bash

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# warmCache.bash causes warms the CUE module cache with any CUE dependencies,
+# so that the credentials used to authenticate to the central registry are only
+# in scope for the duration of this script.
+
+function cleanup() { rm -rfv "${CUE_CONFIG_DIR}"; }
+
+export CUE_CONFIG_DIR="$(mktemp -d)"
+trap cleanup EXIT
+echo "$CUELANG_CUE_LOGINS" >"$CUE_CONFIG_DIR/logins.json"
+go run cuelang.org/go/cmd/cue mod tidy --check

internal/ci/github/trybot.cue

@@ -132,13 +132,8 @@ workflows: trybot: _repo.bashWorkflow & {
 			// TODO: add cache dir to CI cache when it's visible via https://cuelang.org/issue/2838.
 			githubactions.#Step & {
 				name: "Populate CUE dependency cache"
-				env: CUE_LOGINS: "${{ secrets.NOTCUECKOO_CUE_LOGINS }}"
-				run: """
-					export CUE_CONFIG_DIR="$(mktemp -d)"
-					echo "$CUE_LOGINS" >"$CUE_CONFIG_DIR/logins.json"
-					go run cuelang.org/go/cmd/cue mod tidy --check
-					rm -rfv "${CUE_CONFIG_DIR}"
-					"""
+				env: CUELANG_CUE_LOGINS: "${{ secrets.NOTCUECKOO_CUE_LOGINS }}"
+				run: "_scripts/cacheWarm.bash"
 			},
 
 			// We can perform an early check that ensures page.cue files are