tvl-depot/tvix/nar-bridge/pkg/importer/gen_pathinfo.go
Florian Klink 98c17147c6 refactor(tvix/nar-bridge): have Export return root node
… and nar size / sha256 digest.

Instead of producing sparse PathInfo messages when NARs are sent to
nar-bridge, the nar-bridge http server now keeps a lookup table
(narsha256) -> (rootNode, narSize)

This removes a whole bunch of noise, because we don't need to keep
sparse fields around.

A convenience function
`GenPathInfo(rootNode *castorev1pb.Node, narInfo *narinfo.NarInfo)` is
added, which is used to produce PathInfo messages, either when receiving
a NAR file over http and uploading it to a remote PathInfoService, or to
synthesize the PathInfoMessage to return to the client, if nar-bridge is
acting as a PathInfoService for a remove Nix HTTP Binary cache.

Change-Id: Ibba1ab6238a050816c4fab29cb21ae88877d8613
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9651
Tested-by: BuildkiteCI
Reviewed-by: Brian McGee <brian@bmcgee.ie>
2023-10-11 11:41:50 +00:00

62 lines
2.2 KiB
Go

package importer
import (
castorev1pb "code.tvl.fyi/tvix/castore/protos"
storev1pb "code.tvl.fyi/tvix/store/protos"
"fmt"
"github.com/nix-community/go-nix/pkg/narinfo"
"github.com/nix-community/go-nix/pkg/storepath"
)
// GenPathInfo takes a rootNode and narInfo and assembles a PathInfo.
// The rootNode is renamed to match the StorePath in the narInfo.
func GenPathInfo(rootNode *castorev1pb.Node, narInfo *narinfo.NarInfo) (*storev1pb.PathInfo, error) {
// parse the storePath from the .narinfo
storePath, err := storepath.FromAbsolutePath(narInfo.StorePath)
if err != nil {
return nil, fmt.Errorf("unable to parse StorePath: %w", err)
}
// construct the references, by parsing ReferenceNames and extracting the digest
references := make([][]byte, len(narInfo.References))
for i, referenceStr := range narInfo.References {
// parse reference as store path
referenceStorePath, err := storepath.FromString(referenceStr)
if err != nil {
return nil, fmt.Errorf("unable to parse reference %s as storepath: %w", referenceStr, err)
}
references[i] = referenceStorePath.Digest
}
// construct the narInfo.Signatures[*] from pathInfo.Narinfo.Signatures[*]
narinfoSignatures := make([]*storev1pb.NARInfo_Signature, len(narInfo.Signatures))
for i, narinfoSig := range narInfo.Signatures {
narinfoSignatures[i] = &storev1pb.NARInfo_Signature{
Name: narinfoSig.Name,
Data: narinfoSig.Data,
}
}
// assemble the PathInfo.
pathInfo := &storev1pb.PathInfo{
// embed a new root node with the name set to the store path basename.
Node: castorev1pb.RenamedNode(rootNode, storePath.String()),
References: references,
Narinfo: &storev1pb.NARInfo{
NarSize: narInfo.NarSize,
NarSha256: narInfo.FileHash.Digest(),
Signatures: narinfoSignatures,
ReferenceNames: narInfo.References,
},
}
// run Validate on the PathInfo, more as an additional sanity check our code is sound,
// to make sure we populated everything properly, before returning it.
// Fail hard if we fail validation, this is a code error.
if _, err = pathInfo.Validate(); err != nil {
panic(fmt.Sprintf("PathInfo failed validation: %v", err))
}
return pathInfo, nil
}