What causes "missing channel ID" in hyperledger/fabric?

Set ChannelId in the SnapshotRequest/SnapshotQuery to the target channel before signing.

missing channel ID

Error message

missing channel ID

What it means

getLedger resolves the PeerLedger for the channel named in the snapshot request. An empty channelID cannot map to any ledger, so the service short-circuits with 'missing channel ID' before consulting the LedgerGetter.

Source

Thrown at core/ledger/snapshotgrpc/snapshot_service.go:136

	}

	if err := s.ACLProvider.CheckACLNoChannel(
		resName,
		[]*protoutil.SignedData{{
			Identity:  signatureHdr.Creator,
			Data:      signedRequest.Request,
			Signature: signedRequest.Signature,
		}},
	); err != nil {
		return err
	}

	return nil
}

func (s *SnapshotService) getLedger(channelID string) (ledger.PeerLedger, error) {
	if channelID == "" {
		return nil, errors.New("missing channel ID")
	}

	lgr := s.LedgerGetter.GetLedger(channelID)
	if lgr == nil {
		return nil, errors.Errorf("cannot find ledger for channel %s", channelID)
	}

	return lgr, nil
}

View on GitHub (pinned to 2736b63f8f)

Solutions

Set ChannelId in the SnapshotRequest/SnapshotQuery to the target channel before signing.
Check the client CLI/SDK flag (e.g. --channel) is actually supplied and non-empty.
Ensure the channel exists on the peer (peer channel list) — after that, an empty string specifically means the field was never populated.
Validate the request struct before marshaling; fail fast on empty ChannelId.

Example fix

// before
req := &pb.SnapshotRequest{SignatureHeader: hdr} // ChannelId missing
// after
req := &pb.SnapshotRequest{SignatureHeader: hdr, ChannelId: "mychannel"}

Defensive patterns

Strategy: validation

Validate before calling

if req.GetChannelId() == "" {
    return fmt.Errorf("channel ID required for snapshot operations")
}
raw, _ := proto.Marshal(req)
err := svc.Generate(ctx, &pb.SignedSnapshotRequest{Request: raw, Signature: sig})

Type guard

func hasChannelID(r *pb.SnapshotRequest) bool {
    return r != nil && r.GetChannelId() != ""
}

Try / catch

_, err := svc.Generate(ctx, signedReq)
if err != nil && strings.Contains(err.Error(), "missing channel ID") {
    // surface config error: require --channel flag / CHANNEL_ID env before calling
}

Prevention

Fail fast in client code on empty ChannelId before signing.
Make the channel a required CLI/SDK parameter, not an optional default.
Copy ChannelId consistently between SignatureHeader and the request body.

When it happens

Trigger: Generate/Cancel/QueryPendings requests where SnapshotRequest.ChannelId (or the query's channel field) is the empty string — headers/requests built without setting ChannelId.

Common situations: Multi-channel peers where the client omitted the channel selector; CLI tools defaulting to an unset --channel flag; a partially filled SignatureHeader whose ChannelId was not copied into the request body.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/8d75ceaf0043ab7f. Report an issue: GitHub.