rework: address review feedback on PR #126

Changes per sneak's review:
- Delete docker-compose.yml, add example stanza to README
- Define custom domain types: ImageID, ContainerID, UnparsedURL
- Use custom types in all function signatures throughout codebase
- Restore imageID parameter (as domain.ImageID) in deploy pipeline
- buildContainerOptions now takes ImageID directly instead of
  constructing image tag from deploymentID
- Fix pre-existing JS formatting (prettier)

make check passes with zero failures.

Dockerfile

@@ -1,11 +1,11 @@
 # Build stage
-FROM golang:1.25-alpine AS builder
+FROM golang@sha256:f6751d823c26342f9506c03797d2527668d095b0a15f1862cddb4d927a7a4ced AS builder # golang:1.25-alpine
 
 RUN apk add --no-cache git make gcc musl-dev
 
 # Install golangci-lint v2
-RUN go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@latest
+RUN go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@5d1e709b7be35cb2025444e19de266b056b7b7ee # v2.10.1
-RUN go install golang.org/x/tools/cmd/goimports@latest
+RUN go install golang.org/x/tools/cmd/goimports@009367f5c17a8d4c45a961a3a509277190a9a6f0 # v0.42.0
 
 WORKDIR /src
 COPY go.mod go.sum ./
@@ -20,7 +20,7 @@ RUN make check
 RUN make build
 
 # Runtime stage
-FROM alpine:3.19
+FROM alpine@sha256:6baf43584bcb78f2e5847d1de515f23499913ac9f12bdf834811a3145eb11ca1 # alpine:3.19
 
 RUN apk add --no-cache ca-certificates tzdata git openssh-client docker-cli
 

internal/database/testing.go

@@ -0,0 +1,41 @@
+package database
+
+import (
+	"log/slog"
+	"os"
+	"testing"
+
+	"git.eeqj.de/sneak/upaas/internal/config"
+	"git.eeqj.de/sneak/upaas/internal/logger"
+)
+
+// NewTestDatabase creates an in-memory Database for testing.
+// It runs migrations so all tables are available.
+func NewTestDatabase(t *testing.T) *Database {
+	t.Helper()
+
+	tmpDir := t.TempDir()
+
+	cfg := &config.Config{
+		DataDir: tmpDir,
+	}
+
+	log := slog.New(slog.NewTextHandler(os.Stderr, nil))
+	logWrapper := logger.NewForTest(log)
+
+	db, err := New(nil, Params{
+		Logger: logWrapper,
+		Config: cfg,
+	})
+	if err != nil {
+		t.Fatalf("failed to create test database: %v", err)
+	}
+
+	t.Cleanup(func() {
+		if db.database != nil {
+			_ = db.database.Close()
+		}
+	})
+
+	return db
+}

internal/logger/testing.go

@@ -0,0 +1,11 @@
+package logger
+
+import "log/slog"
+
+// NewForTest creates a Logger wrapping the given slog.Logger, for use in tests.
+func NewForTest(log *slog.Logger) *Logger {
+	return &Logger{
+		log:   log,
+		level: new(slog.LevelVar),
+	}
+}

internal/service/deploy/deploy_container_test.go

@@ -0,0 +1,45 @@
+package deploy_test
+
+import (
+	"context"
+	"log/slog"
+	"os"
+	"testing"
+
+	"git.eeqj.de/sneak/upaas/internal/database"
+	"git.eeqj.de/sneak/upaas/internal/domain"
+	"git.eeqj.de/sneak/upaas/internal/models"
+	"git.eeqj.de/sneak/upaas/internal/service/deploy"
+)
+
+func TestBuildContainerOptionsUsesImageID(t *testing.T) {
+	t.Parallel()
+
+	db := database.NewTestDatabase(t)
+
+	app := models.NewApp(db)
+	app.Name = "myapp"
+
+	err := app.Save(context.Background())
+	if err != nil {
+		t.Fatalf("failed to save app: %v", err)
+	}
+
+	log := slog.New(slog.NewTextHandler(os.Stderr, nil))
+	svc := deploy.NewTestService(log)
+
+	const expectedImageID = domain.ImageID("sha256:abc123def456")
+
+	opts, err := svc.BuildContainerOptionsExported(context.Background(), app, expectedImageID)
+	if err != nil {
+		t.Fatalf("buildContainerOptions returned error: %v", err)
+	}
+
+	if opts.Image != string(expectedImageID) {
+		t.Errorf("expected Image=%q, got %q", expectedImageID, opts.Image)
+	}
+
+	if opts.Name != "upaas-myapp" {
+		t.Errorf("expected Name=%q, got %q", "upaas-myapp", opts.Name)
+	}
+}

internal/service/deploy/export_test.go

@@ -10,6 +10,8 @@ import (
 
 	"git.eeqj.de/sneak/upaas/internal/config"
 	"git.eeqj.de/sneak/upaas/internal/docker"
+	"git.eeqj.de/sneak/upaas/internal/domain"
+	"git.eeqj.de/sneak/upaas/internal/models"
 )
 
 // NewTestService creates a Service with minimal dependencies for testing.
@@ -80,3 +82,12 @@ func (svc *Service) CleanupCancelledDeploy(
 func (svc *Service) GetBuildDirExported(appName string) string {
 	return svc.GetBuildDir(appName)
 }
+
+// BuildContainerOptionsExported exposes buildContainerOptions for testing.
+func (svc *Service) BuildContainerOptionsExported(
+	ctx context.Context,
+	app *models.App,
+	imageID domain.ImageID,
+) (docker.CreateContainerOptions, error) {
+	return svc.buildContainerOptions(ctx, app, imageID)
+}