client: make ContainerLogsResult an interface

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

client/container_logs.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"net/url"
-	"sync"
 	"time"
 
 	"github.com/moby/moby/client/internal/timestamp"
@@ -24,9 +23,8 @@ type ContainerLogsOptions struct {
 }
 
 // ContainerLogsResult is the result of a container logs operation.
-type ContainerLogsResult struct {
-	rc    io.ReadCloser
-	close func() error
+type ContainerLogsResult interface {
+	io.ReadCloser
 }
 
 // ContainerLogs returns the logs generated by a container in an [io.ReadCloser].
@@ -58,7 +56,7 @@ type ContainerLogsResult struct {
 func (cli *Client) ContainerLogs(ctx context.Context, containerID string, options ContainerLogsOptions) (ContainerLogsResult, error) {
 	containerID, err := trimID("container", containerID)
 	if err != nil {
-		return ContainerLogsResult{}, err
+		return nil, err
 	}
 
 	query := url.Values{}
@@ -73,7 +71,7 @@ func (cli *Client) ContainerLogs(ctx context.Context, containerID string, option
 	if options.Since != "" {
 		ts, err := timestamp.GetTimestamp(options.Since, time.Now())
 		if err != nil {
-			return ContainerLogsResult{}, fmt.Errorf(`invalid value for "since": %w`, err)
+			return nil, fmt.Errorf(`invalid value for "since": %w`, err)
 		}
 		query.Set("since", ts)
 	}
@@ -81,7 +79,7 @@ func (cli *Client) ContainerLogs(ctx context.Context, containerID string, option
 	if options.Until != "" {
 		ts, err := timestamp.GetTimestamp(options.Until, time.Now())
 		if err != nil {
-			return ContainerLogsResult{}, fmt.Errorf(`invalid value for "until": %w`, err)
+			return nil, fmt.Errorf(`invalid value for "until": %w`, err)
 		}
 		query.Set("until", ts)
 	}
@@ -101,33 +99,33 @@ func (cli *Client) ContainerLogs(ctx context.Context, containerID string, option
 
 	resp, err := cli.get(ctx, "/containers/"+containerID+"/logs", query, nil)
 	if err != nil {
-		return ContainerLogsResult{}, err
+		return nil, err
 	}
-	return newContainerLogsResult(resp.Body), nil
+	return &containerLogsResult{
+		body: resp.Body,
+	}, nil
 }
 
-func newContainerLogsResult(rc io.ReadCloser) ContainerLogsResult {
-	if rc == nil {
-		panic("rc cannot be nil")
-	}
-	return ContainerLogsResult{
-		rc:    rc,
-		close: sync.OnceValue(rc.Close),
-	}
+type containerLogsResult struct {
+	// body must be closed to avoid a resource leak
+	body io.ReadCloser
 }
 
-// Read implements the io.Reader interface.
-func (r ContainerLogsResult) Read(p []byte) (n int, err error) {
-	if r.rc == nil {
+var (
+	_ io.ReadCloser       = (*containerLogsResult)(nil)
+	_ ContainerLogsResult = (*containerLogsResult)(nil)
+)
+
+func (r *containerLogsResult) Read(p []byte) (int, error) {
+	if r == nil || r.body == nil {
 		return 0, io.EOF
 	}
-	return r.rc.Read(p)
+	return r.body.Read(p)
 }
 
-// Close closes the underlying reader.
-func (r ContainerLogsResult) Close() error {
-	if r.close == nil {
+func (r *containerLogsResult) Close() error {
+	if r == nil || r.body == nil {
 		return nil
 	}
-	return r.close()
+	return r.body.Close()
 }

vendor/github.com/moby/moby/client/container_logs.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"net/url"
-	"sync"
 	"time"
 
 	"github.com/moby/moby/client/internal/timestamp"
@@ -24,9 +23,8 @@ type ContainerLogsOptions struct {
 }
 
 // ContainerLogsResult is the result of a container logs operation.
-type ContainerLogsResult struct {
-	rc    io.ReadCloser
-	close func() error
+type ContainerLogsResult interface {
+	io.ReadCloser
 }
 
 // ContainerLogs returns the logs generated by a container in an [io.ReadCloser].
@@ -58,7 +56,7 @@ type ContainerLogsResult struct {
 func (cli *Client) ContainerLogs(ctx context.Context, containerID string, options ContainerLogsOptions) (ContainerLogsResult, error) {
 	containerID, err := trimID("container", containerID)
 	if err != nil {
-		return ContainerLogsResult{}, err
+		return nil, err
 	}
 
 	query := url.Values{}
@@ -73,7 +71,7 @@ func (cli *Client) ContainerLogs(ctx context.Context, containerID string, option
 	if options.Since != "" {
 		ts, err := timestamp.GetTimestamp(options.Since, time.Now())
 		if err != nil {
-			return ContainerLogsResult{}, fmt.Errorf(`invalid value for "since": %w`, err)
+			return nil, fmt.Errorf(`invalid value for "since": %w`, err)
 		}
 		query.Set("since", ts)
 	}
@@ -81,7 +79,7 @@ func (cli *Client) ContainerLogs(ctx context.Context, containerID string, option
 	if options.Until != "" {
 		ts, err := timestamp.GetTimestamp(options.Until, time.Now())
 		if err != nil {
-			return ContainerLogsResult{}, fmt.Errorf(`invalid value for "until": %w`, err)
+			return nil, fmt.Errorf(`invalid value for "until": %w`, err)
 		}
 		query.Set("until", ts)
 	}
@@ -101,33 +99,33 @@ func (cli *Client) ContainerLogs(ctx context.Context, containerID string, option
 
 	resp, err := cli.get(ctx, "/containers/"+containerID+"/logs", query, nil)
 	if err != nil {
-		return ContainerLogsResult{}, err
+		return nil, err
 	}
-	return newContainerLogsResult(resp.Body), nil
+	return &containerLogsResult{
+		body: resp.Body,
+	}, nil
 }
 
-func newContainerLogsResult(rc io.ReadCloser) ContainerLogsResult {
-	if rc == nil {
-		panic("rc cannot be nil")
-	}
-	return ContainerLogsResult{
-		rc:    rc,
-		close: sync.OnceValue(rc.Close),
-	}
+type containerLogsResult struct {
+	// body must be closed to avoid a resource leak
+	body io.ReadCloser
 }
 
-// Read implements the io.Reader interface.
-func (r ContainerLogsResult) Read(p []byte) (n int, err error) {
-	if r.rc == nil {
+var (
+	_ io.ReadCloser       = (*containerLogsResult)(nil)
+	_ ContainerLogsResult = (*containerLogsResult)(nil)
+)
+
+func (r *containerLogsResult) Read(p []byte) (int, error) {
+	if r == nil || r.body == nil {
 		return 0, io.EOF
 	}
-	return r.rc.Read(p)
+	return r.body.Read(p)
 }
 
-// Close closes the underlying reader.
-func (r ContainerLogsResult) Close() error {
-	if r.close == nil {
+func (r *containerLogsResult) Close() error {
+	if r == nil || r.body == nil {
 		return nil
 	}
-	return r.close()
+	return r.body.Close()
 }