ipfs

ipfs-tools

Go library for fetching data from IPFS. It provides two ways to resolve content:

• Gateway pool — fetch documents over HTTP from a list of public/private IPFS gateways with per-gateway rate limiting;
• Embedded node — run an in-process Kubo IPFS node tuned for low resource usage and fetch content directly from the network.

Plus a set of helpers for parsing and validating ipfs:// links.

Installation

go get github.com/dipdup-io/ipfs-tools

Usage

Gateway pool

Pool requests content from HTTP gateways. Each gateway gets its own rate limiter (10 requests per second). Response size is capped by limit (bytes).

package main

import (
	"context"
	"fmt"

	ipfs "github.com/dipdup-io/ipfs-tools"
)

func main() {
	pool, err := ipfs.NewPool([]string{
		"https://ipfs.io",
		"https://cloudflare-ipfs.com",
	}, 1024*1024) // 1 MB response limit
	if err != nil {
		panic(err)
	}

	// tries gateways in random order until one responds
	data, err := pool.Get(context.Background(), "ipfs://QmY7Yh4UquoXHLPFo2XbhXkhBvFoPwmQUSa92pxnxjQuPU")
	if err != nil {
		panic(err)
	}

	fmt.Printf("received %d bytes from %s\n", len(data.Raw), data.Node)
}

Other ways to query the pool:

// single request to one randomly chosen gateway
data, err := pool.GetFromRandomGateway(ctx, link)

// request to a specific gateway
data, err := pool.GetFromNode(ctx, link, "https://ipfs.io")

The pool implements the IPool interface; a gomock mock (MockIPool) is shipped with the package for testing.

Embedded IPFS node

Node spawns an in-process Kubo node. The repo config is tuned to minimize resource usage: no relay/QUIC transports, delegated routing, providing and Bitswap server disabled, connection manager capped at 20–50 peers, 2 GB storage with hourly GC.

node, err := ipfs.NewNode(ctx,
	"/path/to/ipfs-repo",       // repo directory (created if missing)
	1024*1024,                  // read limit in bytes
	[]string{},                 // swarm address blacklist (addr filters)
	[]ipfs.Provider{            // peers to keep persistent connections with
		{ID: "12D3KooW...", Address: "/dns4/example.com/tcp/4001"},
	},
)
if err != nil {
	panic(err)
}

if err := node.Start(ctx); err != nil { // connects to peers, starts periodic GC
	panic(err)
}
defer node.Close()

data, err := node.Get(ctx, "/ipfs/QmY7Yh4UquoXHLPFo2XbhXkhBvFoPwmQUSa92pxnxjQuPU")

Helpers

// extract and validate a CID from a link
hash, err := ipfs.Hash("ipfs://QmY7Yh4UquoXHLPFo2XbhXkhBvFoPwmQUSa92pxnxjQuPU")

// find all ipfs:// links (CIDv0 and CIDv1) in raw bytes
links := ipfs.FindAllLinks(data)

// check whether a string is a valid ipfs:// link
ok := ipfs.Is("ipfs://QmY7Yh4UquoXHLPFo2XbhXkhBvFoPwmQUSa92pxnxjQuPU")

// build a gateway URL from gateway address and hash
url := ipfs.Link("https://ipfs.io", hash) // https://ipfs.io/ipfs/<hash>

// strip the ipfs:// prefix
path := ipfs.Path("ipfs://<hash>") // <hash>

Development

make test   # go test ./...
make lint   # golangci-lint run

Mocks are generated with mockgen:

go generate ./...

License

MIT — see LICENSE.