[patch] Preserve Docker rollback images (#25)

Author: pennypacker-he

internal/contracttest/docker_prune_test.go

@@ -0,0 +1,87 @@
+package contracttest
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+	"slices"
+	"strings"
+	"testing"
+)
+
+func TestDockerPrunePreservesNamedRollbackImages(t *testing.T) {
+	root := repositoryRoot(t)
+	script := filepath.Join(root, "rootfs", "home", "cloud-compose", "docker-prune.sh")
+	temporary := t.TempDir()
+	profile := filepath.Join(temporary, "profile.sh")
+	lock := filepath.Join(temporary, "docker-prune.lock")
+	logPath := filepath.Join(temporary, "docker.log")
+	binDirectory := filepath.Join(temporary, "bin")
+
+	if err := os.Mkdir(binDirectory, 0o755); err != nil {
+		t.Fatalf("create mock binary directory: %v", err)
+	}
+	if err := os.WriteFile(profile, []byte("# test profile\n"), 0o600); err != nil {
+		t.Fatalf("write test profile: %v", err)
+	}
+	mockDocker := []byte("#!/usr/bin/env bash\nset -euo pipefail\nprintf '%s\\n' \"$*\" >> \"${DOCKER_PRUNE_TEST_LOG:?}\"\n")
+	if err := os.WriteFile(filepath.Join(binDirectory, "docker"), mockDocker, 0o755); err != nil {
+		t.Fatalf("write mock Docker binary: %v", err)
+	}
+
+	command := exec.Command("bash", script)
+	command.Env = append(os.Environ(),
+		"CLOUD_COMPOSE_DOCKER_PRUNE_ENABLED=true",
+		"CLOUD_COMPOSE_DOCKER_PRUNE_LOCK_PATH="+lock,
+		"CLOUD_COMPOSE_DOCKER_PRUNE_UNTIL=72h",
+		"CLOUD_COMPOSE_PROFILE_PATH="+profile,
+		"DOCKER_PRUNE_TEST_LOG="+logPath,
+		"PATH="+binDirectory+":"+os.Getenv("PATH"),
+	)
+	if output, err := command.CombinedOutput(); err != nil {
+		t.Fatalf("run Docker prune policy: %v\n%s", err, output)
+	}
+
+	logBytes, err := os.ReadFile(logPath)
+	if err != nil {
+		t.Fatalf("read Docker invocation log: %v", err)
+	}
+	commands := strings.Split(strings.TrimSpace(string(logBytes)), "\n")
+	want := []string{
+		"container prune --force --filter until=72h",
+		"network prune --force --filter until=72h",
+		"image prune --force --filter until=72h",
+		"builder prune --force --filter until=72h",
+	}
+	if !slices.Equal(commands, want) {
+		t.Fatalf("Docker prune commands = %#v, want %#v", commands, want)
+	}
+	for _, invocation := range commands {
+		if strings.Contains(invocation, "system prune") || strings.Contains(invocation, "image prune --all") {
+			t.Fatalf("destructive Docker prune invocation remains: %s", invocation)
+		}
+	}
+}
+
+func TestDockerPruneIsDisabledByDefault(t *testing.T) {
+	root := repositoryRoot(t)
+	script := filepath.Join(root, "rootfs", "home", "cloud-compose", "docker-prune.sh")
+	temporary := t.TempDir()
+	profile := filepath.Join(temporary, "profile.sh")
+	if err := os.WriteFile(profile, []byte("# test profile\n"), 0o600); err != nil {
+		t.Fatalf("write test profile: %v", err)
+	}
+
+	command := exec.Command("bash", script)
+	command.Env = append(os.Environ(),
+		"CLOUD_COMPOSE_DOCKER_PRUNE_ENABLED=",
+		"CLOUD_COMPOSE_PROFILE_PATH="+profile,
+	)
+	output, err := command.CombinedOutput()
+	if err != nil {
+		t.Fatalf("run disabled Docker prune policy: %v\n%s", err, output)
+	}
+	if !strings.Contains(string(output), "Docker pruning is disabled") {
+		t.Fatalf("disabled Docker prune output = %q", output)
+	}
+}

rootfs/home/cloud-compose/docker-prune.sh

@@ -2,8 +2,11 @@
 
 set -euo pipefail
 
-# shellcheck disable=SC1091
-source /home/cloud-compose/profile.sh
+script_dir="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+profile_path="${CLOUD_COMPOSE_PROFILE_PATH:-$script_dir/profile.sh}"
+
+# shellcheck disable=SC1090
+source "$profile_path"
 
 case "${CLOUD_COMPOSE_DOCKER_PRUNE_ENABLED:-false}" in
   true | TRUE | 1 | yes | YES) ;;
@@ -19,11 +22,15 @@ if [[ ! "$prune_until" =~ ^[0-9]+(s|m|h)$ ]]; then
   exit 2
 fi
 
-exec 9>/run/cloud-compose-docker-prune.lock
+lock_path="${CLOUD_COMPOSE_DOCKER_PRUNE_LOCK_PATH:-/run/cloud-compose-docker-prune.lock}"
+exec 9>"$lock_path"
 if command -v flock >/dev/null 2>&1 && ! flock -n 9; then
   echo "A Cloud Compose Docker prune is already running"
   exit 0
 fi
 
-echo "Pruning unused Docker data older than $prune_until"
-docker system prune --all --force --filter "until=$prune_until"
+echo "Pruning stopped containers, unused networks, dangling images, and build cache older than $prune_until"
+docker container prune --force --filter "until=$prune_until"
+docker network prune --force --filter "until=$prune_until"
+docker image prune --force --filter "until=$prune_until"
+docker builder prune --force --filter "until=$prune_until"