Refactor how data dir is initialized

srv/src/cfg/data_dir.go

@@ -0,0 +1,74 @@
+package cfg
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/mediocregopher/mediocre-go-lib/v2/mctx"
+)
+
+// DataDir manages the blog's data directory.
+type DataDir struct {
+	Path string
+
+	deleteOnClose bool
+}
+
+// Init initializes the data directory, creating the directory named at path if
+// it doesn't exist.
+//
+// If Path is not set, then a temporary directory will be created and its path
+// set to the Path field. This directory will be removed when Close is called.
+func (d *DataDir) Init() error {
+	if d.Path == "" {
+
+		d.deleteOnClose = true
+		var err error
+
+		if d.Path, err = os.MkdirTemp("", "mediocre-blog-data-*"); err != nil {
+			return fmt.Errorf("creating temporary directory: %w", err)
+		}
+
+		return nil
+	}
+
+	if err := os.MkdirAll(d.Path, 0700); err != nil {
+		return fmt.Errorf(
+			"creating directory (and parents) of %q: %w",
+			d.Path,
+			err,
+		)
+	}
+
+	return nil
+}
+
+// SetupCfg implement the cfg.Cfger interface.
+func (d *DataDir) SetupCfg(cfg *Cfg) {
+
+	cfg.StringVar(&d.Path, "data-dir", "", "Directory to use for persistent storage. If unset a temp directory will be created, and will be deleted when the process exits.")
+
+	cfg.OnInit(func(ctx context.Context) error {
+		return d.Init()
+	})
+}
+
+// Annotate implements mctx.Annotator interface.
+func (d *DataDir) Annotate(a mctx.Annotations) {
+	a["dataDirPath"] = d.Path
+}
+
+// Close cleans up any temporary state created by DataDir.
+func (d *DataDir) Close() error {
+
+	if !d.deleteOnClose {
+		return nil
+	}
+
+	if err := os.RemoveAll(d.Path); err != nil {
+		return fmt.Errorf("removing temp dir %q: %w", d.Path, err)
+	}
+
+	return nil
+}

srv/src/cfg/mediocre_blog.go

@@ -0,0 +1,9 @@
+package cfg
+
+// this file contains functionality specific to the mediocre blog.
+
+// NewBlogCfg returns a Cfg specifically configured for mediocre blog processes.
+func NewBlogCfg(params Params) *Cfg {
+	params.EnvPrefix = "MEDIOCRE_BLOG"
+	return New(params)
+}

srv/src/cmd/mailinglist-cli/main.go

@@ -4,9 +4,9 @@ import (
 	"context"
 	"errors"
 	"io"
-	"path"
 
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
+	cfgpkg "github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/mailinglist"
 	"github.com/mediocregopher/mediocre-go-lib/v2/mctx"
 	"github.com/mediocregopher/mediocre-go-lib/v2/mlog"
@@ -17,11 +17,12 @@ func main() {
 
 	ctx := context.Background()
 
-	cfg := cfg.New(cfg.Params{
+	cfg := cfgpkg.NewBlogCfg(cfg.Params{})
-		EnvPrefix: "MEDIOCRE_BLOG",
-	})
 
-	dataDir := cfg.String("data-dir", ".", "Directory to use for long term storage")
+	var dataDir cfgpkg.DataDir
+	dataDir.SetupCfg(cfg)
+	defer dataDir.Close()
+	ctx = mctx.WithAnnotator(ctx, &dataDir)
 
 	var mailerParams mailinglist.MailerParams
 	mailerParams.SetupCfg(cfg)
@@ -54,10 +55,7 @@ func main() {
 		mailer = mailinglist.NewMailer(mailerParams)
 	}
 
-	mailingListDBFile := path.Join(*dataDir, "mailinglist.sqlite3")
+	mlStore, err := mailinglist.NewStore(dataDir)
-	ctx = mctx.Annotate(ctx, "mailingListDBFile", mailingListDBFile)
-
-	mlStore, err := mailinglist.NewStore(mailingListDBFile)
 	if err != nil {
 		logger.Fatal(ctx, "initializing mailing list storage", err)
 	}

srv/src/cmd/mediocre-blog/main.go

@@ -4,12 +4,12 @@ import (
 	"context"
 	"os"
 	"os/signal"
-	"path"
 	"syscall"
 	"time"
 
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/api"
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
+	cfgpkg "github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/chat"
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/mailinglist"
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/pow"
@@ -23,11 +23,12 @@ func main() {
 
 	ctx := context.Background()
 
-	cfg := cfg.New(cfg.Params{
+	cfg := cfg.NewBlogCfg(cfg.Params{})
-		EnvPrefix: "MEDIOCRE_BLOG",
-	})
 
-	dataDir := cfg.String("data-dir", ".", "Directory to use for long term storage")
+	var dataDir cfgpkg.DataDir
+	dataDir.SetupCfg(cfg)
+	defer dataDir.Close()
+	ctx = mctx.WithAnnotator(ctx, &dataDir)
 
 	var powMgrParams pow.ManagerParams
 	powMgrParams.SetupCfg(cfg)
@@ -91,10 +92,7 @@ func main() {
 		mailer = mailinglist.NewMailer(mailerParams)
 	}
 
-	mailingListDBFile := path.Join(*dataDir, "mailinglist.sqlite3")
+	mlStore, err := mailinglist.NewStore(dataDir)
-	ctx = mctx.Annotate(ctx, "mailingListDBFile", mailingListDBFile)
-
-	mlStore, err := mailinglist.NewStore(mailingListDBFile)
 	if err != nil {
 		logger.Fatal(ctx, "initializing mailing list storage", err)
 	}

srv/src/mailinglist/store.go

@@ -7,10 +7,12 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"path"
 	"strings"
 	"time"
 
 	_ "github.com/mattn/go-sqlite3"
+	"github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
 	migrate "github.com/rubenv/sql-migrate"
 )
 
@@ -83,13 +85,15 @@ type store struct {
 	db *sql.DB
 }
 
-// NewStore initializes a new Store using a sqlite3 database at the given file
+// NewStore initializes a new Store using a sqlite3 database in the given
-// path.
+// DataDir.
-func NewStore(dbFile string) (Store, error) {
+func NewStore(dataDir cfg.DataDir) (Store, error) {
 
-	db, err := sql.Open("sqlite3", dbFile)
+	path := path.Join(dataDir.Path, "mailinglist.sqlite3")
+
+	db, err := sql.Open("sqlite3", path)
 	if err != nil {
-		return nil, fmt.Errorf("opening sqlite file: %w", err)
+		return nil, fmt.Errorf("opening sqlite file at %q: %w", path, err)
 	}
 
 	migrations := &migrate.MemoryMigrationSource{Migrations: migrations}

srv/src/mailinglist/store_test.go

@@ -2,31 +2,24 @@ package mailinglist
 
 import (
 	"io"
-	"io/ioutil"
-	"os"
 	"testing"
 	"time"
 
+	"github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestStore(t *testing.T) {
-	tmpFile, err := ioutil.TempFile(os.TempDir(), "mediocre-blog-mailinglist-store-test-")
-	if err != nil {
-		t.Fatal("Cannot create temporary file", err)
-	}
-	tmpFilePath := tmpFile.Name()
-	tmpFile.Close()
 
-	t.Logf("using temporary sqlite file at %q", tmpFilePath)
+	var dataDir cfg.DataDir
 
-	t.Cleanup(func() {
+	if err := dataDir.Init(); err != nil {
-		if err := os.Remove(tmpFilePath); err != nil {
+		t.Fatal(err)
-			panic(err)
+	}
-		}
+
-	})
+	t.Cleanup(func() { dataDir.Close() })
 
-	store, err := NewStore(tmpFilePath)
+	store, err := NewStore(dataDir)
 	assert.NoError(t, err)
 
 	t.Cleanup(func() {

srv/src/post/store.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	_ "github.com/mattn/go-sqlite3" // we need dis
+	"github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
 	migrate "github.com/rubenv/sql-migrate"
 )
 
@@ -99,9 +100,7 @@ var migrations = []*migrate.Migration{
 // Params are parameters used to initialize a new Store. All fields are required
 // unless otherwise noted.
 type StoreParams struct {
-
+	DataDir cfg.DataDir
-	// Path to the file the database will be stored at.
-	DBFilePath string
 }
 
 type store struct {
@@ -113,9 +112,11 @@ type store struct {
 // path.
 func NewStore(params StoreParams) (Store, error) {
 
-	db, err := sql.Open("sqlite3", params.DBFilePath)
+	path := path.Join(params.DataDir.Path, "post.sqlite3")
+
+	db, err := sql.Open("sqlite3", path)
 	if err != nil {
-		return nil, fmt.Errorf("opening sqlite file: %w", err)
+		return nil, fmt.Errorf("opening sqlite file at %q: %w", path, err)
 	}
 
 	migrations := &migrate.MemoryMigrationSource{Migrations: migrations}

srv/src/post/store_test.go

@@ -1,13 +1,12 @@
 package post
 
 import (
-	"io/ioutil"
-	"os"
 	"sort"
 	"strconv"
 	"testing"
 	"time"
 
+	"github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
 	"github.com/stretchr/testify/assert"
 	"github.com/tilinna/clock"
 )
@@ -29,25 +28,18 @@ type storeTestHarness struct {
 
 func newStoreTestHarness(t *testing.T) storeTestHarness {
 
-	clock := clock.NewMock(time.Now().UTC().Truncate(1 * time.Hour))
+	var dataDir cfg.DataDir
 
-	tmpFile, err := ioutil.TempFile(os.TempDir(), "mediocre-blog-post-store-test-")
+	if err := dataDir.Init(); err != nil {
-	if err != nil {
+		t.Fatal(err)
-		t.Fatal("Cannot create temporary file", err)
 	}
-	tmpFilePath := tmpFile.Name()
-	tmpFile.Close()
 
-	t.Logf("using temporary sqlite file at %q", tmpFilePath)
+	t.Cleanup(func() { dataDir.Close() })
 
-	t.Cleanup(func() {
+	clock := clock.NewMock(time.Now().UTC().Truncate(1 * time.Hour))
-		if err := os.Remove(tmpFilePath); err != nil {
-			panic(err)
-		}
-	})
 
 	store, err := NewStore(StoreParams{
-		DBFilePath: tmpFilePath,
+		DataDir: dataDir,
 	})
 	assert.NoError(t, err)