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Basic s3 replication working

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This commit is contained in:
Ben Johnson
2021-01-13 14:23:41 -07:00
parent a42f83f3cb
commit 1ac4adb272
4 changed files with 82 additions and 58 deletions
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136
s3/s3.go
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@@ -1,6 +1,7 @@
package s3
import (
"bytes"
"compress/gzip"
"context"
"fmt"
@@ -13,11 +14,13 @@ import (
"time"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/credentials"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/s3"
"github.com/aws/aws-sdk-go/service/s3/s3manager"
"github.com/benbjohnson/litestream"
"github.com/benbjohnson/litestream/internal"
"github.com/davecgh/go-spew/spew"
)
const (
@@ -80,7 +83,7 @@ func (r *Replica) Name() string {
// Type returns the type of replica.
func (r *Replica) Type() string {
return "file"
return "s3"
}
// LastPos returns the last successfully replicated position.
@@ -92,12 +95,12 @@ func (r *Replica) LastPos() litestream.Pos {
// GenerationDir returns the path to a generation's root directory.
func (r *Replica) GenerationDir(generation string) string {
return path.Join("/", r.Path, "generations", generation)
return path.Join(r.Path, "generations", generation)
}
// SnapshotDir returns the path to a generation's snapshot directory.
func (r *Replica) SnapshotDir(generation string) string {
return path.Join("/", r.Path, r.GenerationDir(generation), "snapshots")
return path.Join(r.GenerationDir(generation), "snapshots")
}
// SnapshotPath returns the path to a snapshot file.
@@ -131,11 +134,6 @@ func (r *Replica) WALDir(generation string) string {
return path.Join(r.GenerationDir(generation), "wal")
}
// WALPath returns the path to a WAL file.
func (r *Replica) WALPath(generation string, index int) string {
return path.Join(r.WALDir(generation), fmt.Sprintf("%016x.wal", index))
}
// Generations returns a list of available generation names.
func (r *Replica) Generations(ctx context.Context) ([]string, error) {
if err := r.Init(ctx); err != nil {
@@ -145,15 +143,15 @@ func (r *Replica) Generations(ctx context.Context) ([]string, error) {
var generations []string
if err := r.s3.ListObjectsPages(&s3.ListObjectsInput{
Bucket: aws.String(r.Bucket),
Prefix: aws.String(path.Join("/", r.Path, "generations")),
Prefix: aws.String(path.Join(r.Path, "generations") + "/"),
Delimiter: aws.String("/"),
}, func(page *s3.ListObjectsOutput, lastPage bool) bool {
for _, obj := range page.Contents {
key := path.Base(*obj.Key)
if !litestream.IsGenerationName(key) {
for _, prefix := range page.CommonPrefixes {
name := path.Base(*prefix.Prefix)
if !litestream.IsGenerationName(name) {
continue
}
generations = append(generations, key)
generations = append(generations, name)
}
return true
}); err != nil {
@@ -198,7 +196,7 @@ func (r *Replica) GenerationStats(ctx context.Context, generation string) (stats
func (r *Replica) snapshotStats(generation string) (n int, min, max time.Time, err error) {
if err := r.s3.ListObjectsPages(&s3.ListObjectsInput{
Bucket: aws.String(r.Bucket),
Prefix: aws.String(r.SnapshotDir(generation)),
Prefix: aws.String(r.SnapshotDir(generation) + "/"),
Delimiter: aws.String("/"),
}, func(page *s3.ListObjectsOutput, lastPage bool) bool {
for _, obj := range page.Contents {
@@ -225,7 +223,7 @@ func (r *Replica) snapshotStats(generation string) (n int, min, max time.Time, e
func (r *Replica) walStats(generation string) (n int, min, max time.Time, err error) {
if err := r.s3.ListObjectsPages(&s3.ListObjectsInput{
Bucket: aws.String(r.Bucket),
Prefix: aws.String(r.WALDir(generation)),
Prefix: aws.String(r.WALDir(generation) + "/"),
Delimiter: aws.String("/"),
}, func(page *s3.ListObjectsOutput, lastPage bool) bool {
for _, obj := range page.Contents {
@@ -264,7 +262,7 @@ func (r *Replica) Snapshots(ctx context.Context) ([]*litestream.SnapshotInfo, er
for _, generation := range generations {
if err := r.s3.ListObjectsPages(&s3.ListObjectsInput{
Bucket: aws.String(r.Bucket),
Prefix: aws.String(r.SnapshotDir(generation)),
Prefix: aws.String(r.SnapshotDir(generation) + "/"),
Delimiter: aws.String("/"),
}, func(page *s3.ListObjectsOutput, lastPage bool) bool {
for _, obj := range page.Contents {
@@ -308,7 +306,7 @@ func (r *Replica) WALs(ctx context.Context) ([]*litestream.WALInfo, error) {
var prev *litestream.WALInfo
if err := r.s3.ListObjectsPages(&s3.ListObjectsInput{
Bucket: aws.String(r.Bucket),
Prefix: aws.String(r.WALDir(generation)),
Prefix: aws.String(r.WALDir(generation) + "/"),
Delimiter: aws.String("/"),
}, func(page *s3.ListObjectsOutput, lastPage bool) bool {
for _, obj := range page.Contents {
@@ -419,6 +417,8 @@ func (r *Replica) retainer(ctx context.Context) {
// CalcPos returns the position for the replica for the current generation.
// Returns a zero value if there is no active generation.
func (r *Replica) CalcPos(generation string) (pos litestream.Pos, err error) {
println("dbg/calcpos", generation)
if err := r.Init(context.Background()); err != nil {
return pos, err
}
@@ -429,14 +429,18 @@ func (r *Replica) CalcPos(generation string) (pos litestream.Pos, err error) {
if pos.Index, err = r.MaxSnapshotIndex(generation); err != nil {
return litestream.Pos{}, err
}
println("dbg/calcpos.snapshotindex", pos.Index)
index := -1
var offset int64
if err := r.s3.ListObjectsPages(&s3.ListObjectsInput{
Bucket: aws.String(r.Bucket),
Prefix: aws.String(r.WALDir(generation)),
Prefix: aws.String(r.WALDir(generation) + "/"),
Delimiter: aws.String("/"),
}, func(page *s3.ListObjectsOutput, lastPage bool) bool {
println("dbg/calcpos.page")
spew.Dump(page)
for _, obj := range page.Contents {
key := path.Base(*obj.Key)
@@ -485,7 +489,13 @@ func (r *Replica) snapshot(ctx context.Context, generation string, index int) er
pr, pw := io.Pipe()
gw := gzip.NewWriter(pw)
go func() { io.Copy(gw, f) }()
go func() {
if _, err := io.Copy(gw, f); err != nil {
_ = pw.CloseWithError(err)
return
}
_ = pw.CloseWithError(gw.Close())
}()
snapshotPath := r.SnapshotPath(generation, index)
@@ -496,6 +506,7 @@ func (r *Replica) snapshot(ctx context.Context, generation string, index int) er
}); err != nil {
return err
}
return nil
}
@@ -524,7 +535,10 @@ func (r *Replica) Init(ctx context.Context) (err error) {
return nil
}
sess, err := session.NewSession(&aws.Config{Region: aws.String(r.Region)})
sess, err := session.NewSession(&aws.Config{
Credentials: credentials.NewStaticCredentials(r.AccessKeyID, r.SecretAccessKey, ""),
Region: aws.String(r.Region),
})
if err != nil {
return fmt.Errorf("cannot create aws session: %w", err)
}
@@ -534,6 +548,7 @@ func (r *Replica) Init(ctx context.Context) (err error) {
}
func (r *Replica) Sync(ctx context.Context) (err error) {
println("dbg/s3.sync")
if err := r.Init(ctx); err != nil {
return err
}
@@ -589,27 +604,31 @@ func (r *Replica) syncWAL(ctx context.Context) (err error) {
}
defer rd.Close()
// Ensure parent directory exists for WAL file.
filename := r.WALPath(rd.Pos().Generation, rd.Pos().Index)
if err := os.MkdirAll(path.Dir(filename), 0700); err != nil {
return err
}
// Create a temporary file to write into so we don't have partial writes.
w, err := os.OpenFile(filename, os.O_RDWR|os.O_CREATE, 0600)
// Read to intermediate buffer to determine size.
b, err := ioutil.ReadAll(rd)
if err != nil {
return err
}
defer w.Close()
// Seek, copy & sync WAL contents.
if _, err := w.Seek(rd.Pos().Offset, io.SeekStart); err != nil {
var buf bytes.Buffer
gw := gzip.NewWriter(&buf)
if _, err := gw.Write(b); err != nil {
return err
} else if _, err := io.Copy(w, rd); err != nil {
return err
} else if err := w.Sync(); err != nil {
return err
} else if err := w.Close(); err != nil {
}
// Build a WAL path with the index/offset as well as size so we can ensure
// that files are contiguous without having to decompress.
walPath := path.Join(
r.WALDir(rd.Pos().Generation),
litestream.FormatWALPathWithOffsetSize(rd.Pos().Index, rd.Pos().Offset, int64(len(b)))+".gz",
)
println("dbg/syncwal", walPath)
if _, err := r.uploader.Upload(&s3manager.UploadInput{
Bucket: aws.String(r.Bucket),
Key: aws.String(walPath),
Body: &buf,
}); err != nil {
return err
}
@@ -661,30 +680,33 @@ func (r *Replica) SnapshotReader(ctx context.Context, generation string, index i
// WALReader returns a reader for WAL data at the given index.
// Returns os.ErrNotExist if no matching index is found.
func (r *Replica) WALReader(ctx context.Context, generation string, index int) (io.ReadCloser, error) {
filename := r.WALPath(generation, index)
panic("TODO")
/*
filename := r.WALPath(generation, index)
// Attempt to read uncompressed file first.
f, err := os.Open(filename)
if err == nil {
return f, nil // file exist, return
} else if err != nil && !os.IsNotExist(err) {
return nil, err
}
// Attempt to read uncompressed file first.
f, err := os.Open(filename)
if err == nil {
return f, nil // file exist, return
} else if err != nil && !os.IsNotExist(err) {
return nil, err
}
// Otherwise read the compressed file. Return error if file doesn't exist.
f, err = os.Open(filename + ".gz")
if err != nil {
return nil, err
}
// Otherwise read the compressed file. Return error if file doesn't exist.
f, err = os.Open(filename + ".gz")
if err != nil {
return nil, err
}
// If compressed, wrap in a gzip reader and return with wrapper to
// ensure that the underlying file is closed.
rd, err := gzip.NewReader(f)
if err != nil {
f.Close()
return nil, err
}
return internal.NewReadCloser(rd, f), nil
// If compressed, wrap in a gzip reader and return with wrapper to
// ensure that the underlying file is closed.
rd, err := gzip.NewReader(f)
if err != nil {
f.Close()
return nil, err
}
return internal.NewReadCloser(rd, f), nil
*/
}
// EnforceRetention forces a new snapshot once the retention interval has passed.