kubernetes/kops · error

rendering S3 file: %v

Error message

rendering S3 file: %v

What it means

This error is returned by S3Path.RenderTerraform in util/pkg/vfs/s3fs.go when w.AddFileBytes("aws_s3_object", ...) fails while rendering an S3 bucket object as a terraform resource (the default branch, i.e. AWS S3). AddFileBytes records the object bytes for the terraform output; a failure there means the terraform writer could not stage the file content. It is not an S3 API error — no AWS call has happened yet.

Source

Thrown at util/pkg/vfs/s3fs.go:760

			Key:     p.Key(),
			Content: content,
		}
		return w.RenderResource("scaleway_object", name, tf)

	default:
		bucketDetails, err := p.getBucketDetails(ctx)
		if err != nil {
			return err
		}

		tfProviderArguments := map[string]string{
			"region": bucketDetails.region,
		}
		w.EnsureTerraformProvider("aws", tfProviderArguments)

		content, err := w.AddFileBytes("aws_s3_object", name, "content", bytes, false)
		if err != nil {
			return fmt.Errorf("rendering S3 file: %v", err)
		}

		sse, _, err := p.getServerSideEncryption(ctx)
		if err != nil {
			return err
		}
		sseVal := string(sse)

		requestACL, err := p.getRequestACL(acl)
		if err != nil {
			return err
		}
		var aclVal string
		if requestACL != nil {
			aclVal = string(*requestACL)
		}

		tf := &terraformS3File{

View on GitHub (pinned to 4c8573c808)

Solutions

1. Read the wrapped %v error for the true cause (usually local I/O, not S3)
2. Ensure the terraform output directory (--out) exists and is writable
3. Check disk space on the machine running kops
4. If S3-side settings are the concern, note SSE/ACL are validated after this step; this error is purely about staging content

Example fix

// before
content, err := w.AddFileBytes("aws_s3_object", name, "content", bytes, false)
if err != nil {
	return fmt.Errorf("rendering S3 file: %v", err)
}
// after
// ensure out dir is writable before rendering:
if err := os.MkdirAll(outDir, 0o755); err != nil {
	return fmt.Errorf("creating terraform output dir: %w", err)
}
content, err := w.AddFileBytes("aws_s3_object", name, "content", bytes, false)
if err != nil {
	return fmt.Errorf("rendering S3 file: %w", err)
}

// ensure terraform output target is writable before calling RenderTerraform
if err := os.MkdirAll(outDir, 0o755); err != nil {
	log.Fatalf("cannot prepare terraform out dir: %v", err)
}

if err := p.RenderTerraform(w, name, data, acl); err != nil {
	if strings.Contains(err.Error(), "rendering S3 file:") {
		// local writer problem: inspect wrapped cause and out dir
		log.Printf("S3 terraform staging failed: %+v", err)
	}
	return err
}

When it happens

Trigger: RenderTerraform on an S3Path with the default (aws) scheme where AddFileBytes returns an error — typically when the terraform output target cannot be written or the writer state is invalid.

Common situations: `kops update cluster --target=terraform` against an AWS state store; read-only or missing terraform output directory; corrupted terraform writer context; unusual characters in the object name/path breaking the writer.

Related errors

• rendering S3 file: %v
• cannot parse VFS path %q: %v
• path is not cluster readable: %v
• write to %s with ACL of unexpected type %T
• error reading addons from %q: %v

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/ef2a52447bc6009f. Report an issue: GitHub.