Reproducing and Fixing #2892 (#2893)

* Add an integration test to reproduce #2892

* Fix go compilation

* Fix docker run cmd

* Fixing entrypoint

* Test warmer with cache in a volume.

* Add missing comma

* Fix imports

* Fix dir

* Add logs

* fix

* Use test framework to log

* Fix warmer failing if image already in cache.

* Fix format.

integration/integration_test.go

@@ -28,6 +28,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 	"strconv"
 	"strings"
 	"testing"
@@ -636,6 +637,36 @@ func TestCache(t *testing.T) {
 	}
 }
 
+// Attempt to warm an image two times : first time should populate the cache, second time should find the image in the cache.
+func TestWarmerTwice(t *testing.T) {
+	_, ex, _, _ := runtime.Caller(0)
+	cwd := filepath.Dir(ex) + "/tmpCache"
+
+	// Start a sleeping warmer container
+	dockerRunFlags := []string{"run", "--net=host"}
+	dockerRunFlags = addServiceAccountFlags(dockerRunFlags, config.serviceAccount)
+	dockerRunFlags = append(dockerRunFlags,
+		"--memory=16m",
+		"-v", cwd+":/cache",
+		WarmerImage,
+		"--cache-dir=/cache",
+		"-i", "debian:trixie-slim")
+
+	warmCmd := exec.Command("docker", dockerRunFlags...)
+	out, err := RunCommandWithoutTest(warmCmd)
+	if err != nil {
+		t.Fatalf("Unable to perform first warming: %s", err)
+	}
+	t.Logf("First warm output: %s", out)
+
+	warmCmd = exec.Command("docker", dockerRunFlags...)
+	out, err = RunCommandWithoutTest(warmCmd)
+	if err != nil {
+		t.Fatalf("Unable to perform second warming: %s", err)
+	}
+	t.Logf("Second warm output: %s", out)
+}
+
 func verifyBuildWith(t *testing.T, cache, dockerfile string) {
 	args := []string{}
 	if strings.HasPrefix(dockerfile, "Dockerfile_test_cache_copy") {

pkg/cache/warm.go

@@ -97,10 +97,11 @@ func warmToFile(cacheDir, img string, opts *config.WarmerOptions) error {
 
 	digest, err := cw.Warm(img, opts)
 	if err != nil {
-		if !IsAlreadyCached(err) {
-			logrus.Warnf("Error while trying to warm image: %v %v", img, err)
+		if IsAlreadyCached(err) {
+			logrus.Infof("Image already in cache: %v", img)
+			return nil
 		}
-
+		logrus.Warnf("Error while trying to warm image: %v %v", img, err)
 		return err
 	}