Improve error handling

vm/internal/backend/size.go

@@ -11,7 +11,6 @@ import (
 	"strconv"
 	"strings"
 
-  "github.com/bugsnag/bugsnag-go/v2"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/client"
@@ -24,19 +23,19 @@ type VolumeSize struct {
 	Human string
 }
 
-func GetVolumesSize(ctx context.Context, cli *client.Client, volumeName string) map[string]VolumeSize {
+func GetVolumesSize(ctx context.Context, cli *client.Client, volumeName string) (map[string]VolumeSize, error) {
+	m := make(map[string]VolumeSize)
+
 	// Ensure the image is present before creating the container
 	reader, err := cli.ImagePull(ctx, internal.NsenterImage, types.ImagePullOptions{
 		Platform: "linux/" + runtime.GOARCH,
 	})
 	if err != nil {
-		log.Error(err)
-		_ = bugsnag.Notify(err, ctx)
+		return m, err
 	}
 	_, err = io.Copy(os.Stdout, reader)
 	if err != nil {
-		log.Error(err)
-		_ = bugsnag.Notify(err, ctx)
+		return m, err
 	}
 
 	resp, err := cli.ContainerCreate(ctx, &container.Config{
@@ -55,42 +54,36 @@ func GetVolumesSize(ctx context.Context, cli *client.Client, volumeName string)
 		Privileged: true,
 	}, nil, nil, "")
 	if err != nil {
-		log.Error(err)
-		_ = bugsnag.Notify(err, ctx)
+		return m, err
 	}
 
 	if err := cli.ContainerStart(ctx, resp.ID, types.ContainerStartOptions{}); err != nil {
-		log.Error(err)
-		_ = bugsnag.Notify(err, ctx)
+		return m, err
 	}
 
 	statusCh, errCh := cli.ContainerWait(ctx, resp.ID, container.WaitConditionNotRunning)
 	select {
 	case err := <-errCh:
 		if err != nil {
-			log.Error(err)
-			_ = bugsnag.Notify(err, ctx)
+			return m, err
 		}
 	case <-statusCh:
 	}
 
 	out, err := cli.ContainerLogs(ctx, resp.ID, types.ContainerLogsOptions{ShowStdout: true})
 	if err != nil {
-		log.Error(err)
-		_ = bugsnag.Notify(err, ctx)
+		return m, err
 	}
 
 	buf := new(bytes.Buffer)
 	_, err = buf.ReadFrom(out)
 	if err != nil {
-		log.Error(err)
-		_ = bugsnag.Notify(err, ctx)
+		return m, err
 	}
 
 	output := buf.String()
 
 	lines := strings.Split(strings.TrimSuffix(output, "\n"), "\n")
-	m := make(map[string]VolumeSize)
 	for _, line := range lines {
 		s := strings.Split(line, "\t") // e.g. 924	/var/lib/docker/volumes/my-volume
 		if len(s) != 2 {
@@ -126,11 +119,10 @@ func GetVolumesSize(ctx context.Context, cli *client.Client, volumeName string)
 
 	err = cli.ContainerRemove(ctx, resp.ID, types.ContainerRemoveOptions{})
 	if err != nil {
-		log.Error(err)
-		_ = bugsnag.Notify(err, ctx)
+		return m, err
 	}
 
-	return m
+	return m, nil
 }
 
 // byteCountSI converts a size in bytes to a human-readable string in SI (decimal) format.

vm/internal/handler/clone_test.go

@@ -96,7 +96,8 @@ func TestCloneVolume(t *testing.T) {
 		t.Fatal(err)
 	}
 	require.Len(t, clonedVolumeResp.Volumes, 1)
-	sizes := backend.GetVolumesSize(context.Background(), dockerClient, destVolume)
+	sizes, err := backend.GetVolumesSize(context.Background(), dockerClient, destVolume)
+	require.NoError(t, err)
 	require.Equal(t, int64(16000), sizes[destVolume].Bytes)
 	require.Equal(t, "16.0 kB", sizes[destVolume].Human)
 }

vm/internal/handler/export.go

@@ -9,11 +9,11 @@ import (
 	"runtime"
 	"strings"
 
-  "github.com/bugsnag/bugsnag-go/v2"
-	"github.com/docker/docker/pkg/stdcopy"
-	"github.com/docker/volumes-backup-extension/internal"
+	"github.com/bugsnag/bugsnag-go/v2"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
+	"github.com/docker/docker/pkg/stdcopy"
+	"github.com/docker/volumes-backup-extension/internal"
 	"github.com/docker/volumes-backup-extension/internal/backend"
 	"github.com/docker/volumes-backup-extension/internal/log"
 	"github.com/labstack/echo"

vm/internal/handler/import.go

@@ -7,7 +7,7 @@ import (
 	"os"
 	"runtime"
 
-  "github.com/bugsnag/bugsnag-go/v2"
+	"github.com/bugsnag/bugsnag-go/v2"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/pkg/stdcopy"

vm/internal/handler/import_test.go

@@ -61,7 +61,8 @@ func TestImportTarGzFile(t *testing.T) {
 
 	require.NoError(t, err)
 	require.Equal(t, http.StatusOK, rec.Code)
-	sizes := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	sizes, err := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	require.NoError(t, err)
 	require.Equal(t, int64(16000), sizes[volume].Bytes)
 	require.Equal(t, "16.0 kB", sizes[volume].Human)
 }
@@ -142,7 +143,8 @@ func TestImportTarGzFileShouldRemovePreviousVolumeData(t *testing.T) {
 
 	require.NoError(t, err)
 	require.Equal(t, http.StatusOK, rec.Code)
-	sizes := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	sizes, err := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	require.NoError(t, err)
 	require.Equal(t, int64(16000), sizes[volume].Bytes)
 	require.Equal(t, "16.0 kB", sizes[volume].Human)
 }

vm/internal/handler/load_test.go

@@ -74,7 +74,8 @@ func TestLoadImage(t *testing.T) {
 
 	require.NoError(t, err)
 	require.Equal(t, http.StatusOK, rec.Code)
-	sizes := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	sizes, err := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	require.NoError(t, err)
 	t.Logf("Volume size after loading image into it: %+v", sizes[volume])
 	require.Equal(t, int64(16000), sizes[volume].Bytes)
 	require.Equal(t, "16.0 kB", sizes[volume].Human)
@@ -169,7 +170,8 @@ func TestLoadImageShouldRemovePreviousVolumeData(t *testing.T) {
 
 	require.NoError(t, err)
 	require.Equal(t, http.StatusOK, rec.Code)
-	sizes := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	sizes, err := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	require.NoError(t, err)
 	t.Logf("Volume size after loading image into it: %+v", sizes[volume])
 	require.Equal(t, int64(16000), sizes[volume].Bytes)
 	require.Equal(t, "16.0 kB", sizes[volume].Human)

vm/internal/handler/pull_test.go

@@ -175,7 +175,8 @@ func TestPullVolume(t *testing.T) {
 	require.Equal(t, http.StatusCreated, rec.Code)
 
 	// Check the content of the volume
-	m := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	m, err := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	require.NoError(t, err)
 	require.Equal(t, int64(16000), m[volume].Bytes)
 	require.Equal(t, "16.0 kB", m[volume].Human)
 }
@@ -342,7 +343,8 @@ func TestPullVolumeUsingCorrectAuth(t *testing.T) {
 	require.Equal(t, http.StatusCreated, rec.Code)
 
 	// Check the content of the volume
-	m := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	m, err := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	require.NoError(t, err)
 	require.Equal(t, int64(16000), m[volume].Bytes)
 	require.Equal(t, "16.0 kB", m[volume].Human)
 }
@@ -481,7 +483,8 @@ func TestPullVolumeUsingWrongAuthShouldFail(t *testing.T) {
 	require.Equal(t, http.StatusUnauthorized, rec.Code)
 
 	// Check the content of the volume
-	m := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	m, err := backend.GetVolumesSize(c.Request().Context(), cli, volume)
+	require.NoError(t, err)
 	require.Equal(t, int64(0), m[volume].Bytes)
 	require.Equal(t, "0 B", m[volume].Human)
 }

vm/internal/handler/save.go

@@ -3,7 +3,7 @@ package handler
 import (
 	"net/http"
 
-  "github.com/bugsnag/bugsnag-go/v2"
+	"github.com/bugsnag/bugsnag-go/v2"
 	"github.com/docker/volumes-backup-extension/internal/backend"
 	"github.com/docker/volumes-backup-extension/internal/log"
 	"github.com/labstack/echo"
@@ -27,7 +27,7 @@ func (h *Handler) SaveVolume(ctx echo.Context) error {
 	cli, err := h.DockerClient()
 	if err != nil {
 		log.Error(err)
-    _ = bugsnag.Notify(err, ctxReq)
+		_ = bugsnag.Notify(err, ctxReq)
 		return ctx.String(http.StatusInternalServerError, err.Error())
 	}
 	defer func() {

vm/internal/handler/size.go

@@ -1,6 +1,7 @@
 package handler
 
 import (
+	"github.com/bugsnag/bugsnag-go/v2"
 	"net/http"
 
 	"github.com/docker/volumes-backup-extension/internal/backend"
@@ -9,14 +10,21 @@ import (
 )
 
 func (h *Handler) VolumeSize(ctx echo.Context) error {
+	ctxReq := ctx.Request().Context()
 	volumeName := ctx.Param("volume")
 	cli, err := h.DockerClient()
 	if err != nil {
 		log.Error(err)
+		_ = bugsnag.Notify(err, ctxReq)
 		return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
 	}
 
-	m := backend.GetVolumesSize(ctx.Request().Context(), cli, volumeName)
+	m, err := backend.GetVolumesSize(ctxReq, cli, volumeName)
+	if err != nil {
+		log.Error(err)
+		_ = bugsnag.Notify(err, ctxReq)
+		return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
+	}
 
 	return ctx.JSON(http.StatusOK, m[volumeName])
 }

vm/internal/handler/volumes.go

@@ -5,7 +5,7 @@ import (
 	"net/http"
 	"sync"
 
-  "github.com/bugsnag/bugsnag-go/v2"
+	"github.com/bugsnag/bugsnag-go/v2"
 	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/volumes-backup-extension/internal/backend"
 	"github.com/docker/volumes-backup-extension/internal/log"
@@ -30,10 +30,10 @@ func (h *Handler) Volumes(ctx echo.Context) error {
 	cli, err := h.DockerClient()
 	if err != nil {
 		log.Error(err)
-    _ = bugsnag.Notify(err, ctxReq)
+		_ = bugsnag.Notify(err, ctxReq)
 		return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
 	}
-  
+
 	v, err := cli.VolumeList(ctx.Request().Context(), filters.NewArgs())
 	if err != nil {
 		log.Error(err)
@@ -48,7 +48,13 @@ func (h *Handler) Volumes(ctx echo.Context) error {
 	// Calculating the volume size by spinning a container that execs "du " **per volume** is too time-consuming.
 	// To reduce the time it takes, we get the volumes size by running only one container that execs "du"
 	// into the /var/lib/docker/volumes inside the VM.
-	volumesSize := backend.GetVolumesSize(ctxReq, cli, "*")
+	volumesSize, err := backend.GetVolumesSize(ctxReq, cli, "*")
+	if err != nil {
+		log.Error(err)
+		_ = bugsnag.Notify(err, ctxReq)
+		return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
+	}
+
 	res.Lock()
 	for k, v := range volumesSize {
 		entry, ok := res.data[k]

vm/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"flag"
+	"github.com/bugsnag/bugsnag-go/v2"
 	"net"
 	"net/http"
 	"os"
@@ -12,7 +13,7 @@ import (
 	"github.com/docker/docker/client"
 	"github.com/docker/volumes-backup-extension/internal/handler"
 	"github.com/docker/volumes-backup-extension/internal/log"
-  "github.com/docker/volumes-backup-extension/internal/setup"
+	"github.com/docker/volumes-backup-extension/internal/setup"
 	"github.com/labstack/echo"
 	"github.com/labstack/echo/middleware"
 )
@@ -48,15 +49,16 @@ func main() {
 	log.Infof("Starting listening on %s\n", socketPath)
 	ln, err := net.Listen("unix", socketPath)
 	if err != nil {
+		_ = bugsnag.Notify(err)
 		log.Fatal(err)
 	}
 	router.Listener = ln
 
 	cliFactory := func() (*client.Client, error) {
-
 		return client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
 	}
 	if err != nil {
+		_ = bugsnag.Notify(err)
 		log.Fatal(err)
 	}
 
@@ -82,6 +84,7 @@ func main() {
 		setup.ConfigureBugsnagHandler(server)
 
 		if err := router.StartServer(server); err != nil && err != http.ErrServerClosed {
+			_ = bugsnag.Notify(err)
 			log.Fatal("shutting down the server")
 		}
 	}()
@@ -94,6 +97,7 @@ func main() {
 	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
 	if err := router.Shutdown(ctx); err != nil {
+		_ = bugsnag.Notify(err)
 		log.Fatal(err)
 	}
 }