Remove a build's throwaway containers with their anonymous volumes, so a build node's disk does not fill (issue 1772)

internal/builder/kill_test.go

@@ -2,6 +2,7 @@ package builder
 
 import (
 	"context"
+	"errors"
 	"reflect"
 	"strings"
 	"testing"
@@ -49,7 +50,8 @@ func TestAKillRemovesTheContainersLabelledWithTheBuild(t *testing.T) {
 	if err != nil || n != 2 {
 		t.Fatalf("%d %v", n, err)
 	}
-	if want := []string{"docker ps -aq --filter label=mesh.build=build-3", "docker rm -f c1 c2"}; !reflect.DeepEqual(ran, want) {
+	if want := []string{"docker ps -aq --filter label=mesh.build=build-3", "docker inspect --format " + MountedVolumes + " c1 c2",
+		"docker rm -f -v c1 c2"}; !reflect.DeepEqual(ran, want) {
 		t.Errorf("ran %v", ran)
 	}
 }
@@ -73,7 +75,7 @@ func TestAStartingHolderRemovesWhatEarlierHoldersLeftAndNothingElse(t *testing.T
 	if n != 3 {
 		t.Errorf("removed %d", n)
 	}
-	if len(ran) != 2 || !reflect.DeepEqual(ran[1], []string{"docker", "rm", "-f", "c1", "c2", "c7"}) {
+	if len(ran) != 3 || !reflect.DeepEqual(ran[2], []string{"docker", "rm", "-f", "-v", "c1", "c2", "c7"}) {
 		t.Fatalf("ran %v", ran)
 	}
 	if !strings.Contains(strings.Join(ran[0], " "), "--filter label=mesh.build") {
@@ -90,3 +92,54 @@ func TestAStartingHolderRemovesWhatEarlierHoldersLeftAndNothingElse(t *testing.T
 		t.Errorf("with nothing of the seat's: %d %v %v", n, err, ran)
 	}
 }
+
+// **Issue 1772**: a throwaway store declares its data directory a VOLUME, so docker makes an anonymous volume for
+// it, and `docker rm -f` without -v leaves that volume behind (1,629 of them, 107 GB, on one build node). Every
+// container a build or check removes is removed with its anonymous volumes (-v), and any volume the container
+// mounted that is still there afterwards is removed by name — those, and only those, never a named volume.
+func TestARemovedContainerTakesItsAnonymousVolumesWithIt(t *testing.T) {
+	anon := strings.Repeat("a", 64)
+	other := strings.Repeat("b", 64)
+	var ran []string
+	run := func(_ context.Context, _ string, name string, args ...string) (string, error) {
+		ran = append(ran, name+" "+strings.Join(args, " "))
+		switch args[0] {
+		case "ps":
+			return "c1\n", nil
+		case "inspect":
+			return anon + "\n" + "compose_data\n" + other + "\n", nil
+		}
+		return "", nil
+	}
+	if n, err := RemoveContainersOf(context.Background(), run, "build-4"); err != nil || n != 1 {
+		t.Fatalf("%d %v", n, err)
+	}
+	last := ran[len(ran)-1]
+	if want := "docker volume rm " + anon + " " + other; last != want {
+		t.Errorf("last command %q, want %q", last, want)
+	}
+	if !strings.Contains(strings.Join(ran, "\n"), "docker rm -f -v c1") {
+		t.Errorf("ran %v", ran)
+	}
+	if strings.Contains(last, "compose_data") {
+		t.Errorf("a named volume was removed: %q", last)
+	}
+}
+
+// A volume already gone when the sweep looks (rm -v took it) is no failure.
+func TestAVolumeAlreadyGoneIsNoFailure(t *testing.T) {
+	run := func(_ context.Context, _ string, name string, args ...string) (string, error) {
+		switch args[0] {
+		case "ps":
+			return "c1\n", nil
+		case "inspect":
+			return strings.Repeat("c", 64) + "\n", nil
+		case "volume":
+			return "", errors.New("no such volume")
+		}
+		return "", nil
+	}
+	if n, err := RemoveContainersOf(context.Background(), run, "build-5"); err != nil || n != 1 {
+		t.Fatalf("%d %v", n, err)
+	}
+}