diff --git a/litestream/README.md b/litestream/README.md
index 1cab475..440797d 100644
--- a/litestream/README.md
+++ b/litestream/README.md
@@ -50,3 +50,7 @@ These costs are shown in monthly units, but are billed per 100 milliseconds of a
Since it's just SQLite, this also supports standard SQL operations and semantics. It can be trivially tested locally without access to a cloud instance, or moved to other Litestream-compatible backends like S3.
There are also potentially tenancy benefits to using a separate database for each user, which can be easily achieved with multiple SQLite instances.
+
+### Running locally
+
+Since the database is just SQLite, it's very easy to run this locally. Simply `go run ./` and the service will create `db.sqlite` in the current directory. You can browse to http://localhost:8080/ to see the service running, and interact with the database using standard tools.
diff --git a/litestream/go.mod b/litestream/go.mod
index e7556ad..0028f80 100644
--- a/litestream/go.mod
+++ b/litestream/go.mod
@@ -3,6 +3,7 @@ module github.com/imjasonh/terraform-playground/litestream
go 1.21.5
require (
+ cloud.google.com/go/compute/metadata v0.3.0
github.com/chainguard-dev/clog v1.3.1
github.com/glebarez/go-sqlite v1.22.0
)
diff --git a/litestream/go.sum b/litestream/go.sum
index 3591dc4..c0467ab 100644
--- a/litestream/go.sum
+++ b/litestream/go.sum
@@ -1,3 +1,5 @@
+cloud.google.com/go/compute/metadata v0.3.0 h1:Tz+eQXMEqDIKRsmY3cHTL6FVaynIjX2QxYC4trgAKZc=
+cloud.google.com/go/compute/metadata v0.3.0/go.mod h1:zFmK7XCadkQkj6TtorcaGlCW1hT1fIilQDwofLpJ20k=
github.com/chainguard-dev/clog v1.3.1 h1:CDNCty5WKQhJzoOPubk0GdXt+bPQyargmfClqebrpaQ=
github.com/chainguard-dev/clog v1.3.1/go.mod h1:cV516KZWqYc/phZsCNwF36u/KMGS+Gj5Uqeb8Hlp95Y=
github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
diff --git a/litestream/main.go b/litestream/main.go
index c48ef58..6d0a0ae 100644
--- a/litestream/main.go
+++ b/litestream/main.go
@@ -2,7 +2,6 @@ package main
import (
"database/sql"
- "errors"
"flag"
"fmt"
"html/template"
@@ -12,44 +11,51 @@ import (
"os/exec"
"time"
+ "cloud.google.com/go/compute/metadata"
"github.com/chainguard-dev/clog"
_ "github.com/chainguard-dev/clog/gcp/init"
_ "github.com/glebarez/go-sqlite"
)
-var dbfile = flag.String("file", "/data/db.sqlite", "path to database file")
+var dbfile = flag.String("file", "db.sqlite", "path to database file")
func main() {
flag.Parse()
- if _, err := os.Stat(*dbfile); errors.Is(err, os.ErrNotExist) {
- if os.Getenv("BUCKET") != "" {
- // Before serving requests, restore the database from the latest replica.
- start := time.Now()
- cmd := exec.Command("litestream", "restore",
- "-o", *dbfile,
- fmt.Sprintf("gcs://%s/litestream", os.Getenv("BUCKET")))
- cmd.Stdout = os.Stdout
- cmd.Stderr = os.Stderr
- if err := cmd.Run(); err != nil {
- clog.Fatalf("failed to restore database: %v", err)
- }
- clog.Infof("restoring database took %s", time.Since(start))
- } else {
- clog.Infof("creating database file: %s", *dbfile)
- if _, err := os.Create(*dbfile); err != nil {
+ dbfile := *dbfile
+
+ if metadata.OnGCE() {
+ if os.Getenv("BUCKET") == "" {
+ clog.Fatal("BUCKET environment variable is required on GCE")
+ }
+ dbfile = "/data/" + dbfile
+ // Before serving requests, restore the database from the latest replica.
+ start := time.Now()
+ cmd := exec.Command("litestream", "restore",
+ "-o", dbfile,
+ fmt.Sprintf("gcs://%s/litestream", os.Getenv("BUCKET")))
+ cmd.Stdout = os.Stdout
+ cmd.Stderr = os.Stderr
+ if err := cmd.Run(); err != nil {
+ clog.Fatalf("failed to restore database: %v", err)
+ }
+ clog.Infof("restoring database took %s", time.Since(start))
+ } else {
+ if _, err := os.Stat(dbfile); os.IsNotExist(err) {
+ clog.Infof("creating database file: %s", dbfile)
+ if _, err := os.Create(dbfile); err != nil {
clog.Fatalf("failed to create database file: %v", err)
}
}
}
- fi, err := os.Stat(*dbfile)
+ fi, err := os.Stat(dbfile)
if err != nil {
clog.Fatalf("failed to stat database: %v", err)
}
clog.Infof("database size: %d bytes", fi.Size())
- db, err := sql.Open("sqlite", *dbfile)
+ db, err := sql.Open("sqlite", dbfile)
if err != nil {
clog.Fatalf("failed to open database: %v", err)
}
@@ -65,7 +71,7 @@ func main() {
http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
return
}
- data, err := getData(db)
+ data, err := getData(db, true)
if err != nil {
clog.Fatalf("failed to get data: %v", err)
}
@@ -78,7 +84,7 @@ func main() {
http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
return
}
- data, err := getData(db)
+ data, err := getData(db, false)
if err != nil {
clog.Fatalf("failed to get data: %v", err)
}
@@ -89,11 +95,13 @@ func main() {
log.Fatal(http.ListenAndServe(":8080", nil))
}
-func getData(db *sql.DB) (data, error) {
- row := db.QueryRow("select sqlite_version()")
+func getData(db *sql.DB, getVersion bool) (data, error) {
var version string
- if err := row.Scan(&version); err != nil {
- return data{}, fmt.Errorf("failed to query database version: %w", err)
+ if getVersion {
+ row := db.QueryRow("select sqlite_version()")
+ if err := row.Scan(&version); err != nil {
+ return data{}, fmt.Errorf("failed to query database version: %w", err)
+ }
}
if _, err := db.Exec("insert into test3 (time) values (unixepoch('now','subsec'))"); err != nil {
@@ -128,8 +136,8 @@ var (
litestream
+ sqlite version: {{.Version}}
-
sqlite version: {{.Version}}
count: {{.Count}}
-
sqlite version: {{.Version}}
count: {{.Count}}