ci: Uses worker cache from main GHA cache

be79188 added in new GHA caches for
worker images.
The hope here is to be able to use these to cut down on a bunch of CI
time.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>

Author: cpuguy83

.github/workflows/ci.yml

@@ -153,6 +153,8 @@ jobs:
         run: docker run --rm --privileged tonistiigi/binfmt:latest --install all
       - name: Setup source policy
         uses: ./.github/actions/setup-source-policy
+      - name: Expose GitHub tokens for caching
+        uses: crazy-max/ghaction-github-runtime@3cb05d89e1f492524af3d41a1c98c83bc3025124 # v3.1.0
       - name: Run integration tests
         run: |
           set -ex

docker-bake.hcl

@@ -78,6 +78,12 @@ target "runc-azlinux" {
     tags = tgt == "container" ? ["runc:mariner2"] : []
     // only output non-container targets to the fs
     output = tgt != "container" ? ["_output"] : []
+    cache-from = [
+      {
+        type = "gha"
+        scope = "main.${distro}/worker"
+      }
+    ]
 }
 
 target "runc-jammy" {
@@ -101,6 +107,12 @@ target "runc-jammy" {
     tags = tgt == "container" ? ["runc:jammy"] : []
     // only output non-container targets to the fs
     output = tgt != "container" ? ["_output"] : []
+    cache-from = [
+      {
+        type = "gha"
+        scope = "main.jammy/worker"
+      }
+    ]
 }
 
 target "runc-test" {
@@ -176,6 +188,12 @@ dependencies:
     }
     target = "${distro}/container/depsonly"
     tags = ["local/dalec/deps-only:${distro}"]
+    cache-from = [
+      {
+        type = "gha"
+        scope = "main.${distro}/worker"
+      }
+    ]
 }
 
 target "test-deps-only" {

test/testenv/build.go

@@ -4,9 +4,12 @@ import (
 	"bufio"
 	"context"
 	"encoding/json"
+	"fmt"
 	"io"
 	"os"
+	"path"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/moby/buildkit/client"
@@ -209,3 +212,39 @@ func lookupProjectRoot(cur string) (string, error) {
 
 	return cur, nil
 }
+
+func withCICache(opts *client.SolveOpt) {
+	if os.Getenv("GITHUB_ACTIONS") != "true" {
+		// not running in a github action, nothing to do
+		return
+	}
+
+	// token and url are required for the cache to work.
+	// These need to be exposed as environment variables in the GitHub Actions workflow.
+	// See the crazy-max/ghaction-github-runtime@v3 action.
+	token := os.Getenv("ACTIONS_RUNTIME_TOKEN")
+	if token == "" {
+		fmt.Fprintln(os.Stderr, "::warning::GITHUB_ACTIONS_RUNTIME_TOKEN is not set, skipping cache export")
+		return
+	}
+
+	url := os.Getenv("ACTIONS_CACHE_URL")
+	if url == "" {
+		fmt.Fprintln(os.Stderr, "::warning::ACTIONS_CACHE_URL is not set, skipping cache export")
+		return
+	}
+
+	target, _, ok := strings.Cut(opts.FrontendAttrs["target"], "/")
+	if !ok && target == "" {
+		return
+	}
+
+	opts.CacheImports = append(opts.CacheImports, client.CacheOptionsEntry{
+		Type: "gha",
+		Attrs: map[string]string{
+			"scope": "main." + path.Join(target, "worker"),
+			"token": token,
+			"url":   url,
+		},
+	})
+}

test/testenv/buildx.go

@@ -357,6 +357,8 @@ func (b *BuildxEnv) RunTest(ctx context.Context, t *testing.T, f TestFunc, opts
 		f(&so)
 	}
 
+	withCICache(&so)
+
 	_, err = c.Build(ctx, so, "", func(ctx context.Context, gwc gwclient.Client) (*gwclient.Result, error) {
 		gwc = &clientForceDalecWithInput{gwc}