milk / nsscache-go

Generate your nss cache files with Go

nsscache-go

Implementation of nsscache in Go. The main goal of this library is too allow to write easily new program which can populate the nsscache files from not yet supported sources or to use your custom logic to generate those cache files.

Running the test

To run the test against libnss-cache, you need to have docker installer, and build the test image.

cd docker
docker build -t nsscache-go:latest .

See

• nsscache
• libnss-cache

nsscache-go's Issues

Indexes are not generated

This library is pretty good so far for my use cases, but it doesn't seem to generate the indexes that are specified in the libnss-cache documentation. I can PR in this functionality if you'd like, or you can use the functions I've provided below which can be used to generate the indexes.

func genIndex(lines []string, indexCol int) map[string]int {
	iMap := make(map[string]int)
	offset := 0

	for _, l := range lines {
		key := strings.Split(l, ":")[indexCol]
		iMap[key] = offset
		offset += len(l) + 1
	}
	return iMap
}

func writeIndex(index map[string]int, location string) error {
	keyList := []string{}
	for k := range index {
		keyList = append(keyList, k)
	}

	sort.Strings(keyList)

	var b bytes.Buffer
	for _, key := range keyList {
		value := index[key]
		fmt.Fprintf(&b, "%s", key)
		fmt.Fprintf(&b, "\x00")
		fmt.Fprintf(&b, "%08d", int64(value))
		for i := 0; i < 32-len(key)-1; i++ {
			fmt.Fprint(&b, "\x00")
		}
		fmt.Fprintf(&b, "\n")
	}
	return ioutil.WriteFile(location, b.Bytes(), 0644)
}

Four indexes in total need to be generated, two each for passwd and group, each by both the string representation and the number. The reason this works right now is that if the indexes aren't present libnss-cache will fall back to trying a linear search through the maps, but this will fail for maps beyond a certain size.

Release 0.1.0

I'd like to use this library to replace the hacky string processing in NetAuth/nsscache, but to do that, I'd feel much comfortable if I could lock to a particular release of this library. Would you consider releasing 0.1 to facilitate this?