fix(rpc): cross-platform support for /unix/ socket maddrs in Addresses.API

client/rpc/api.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"net"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -98,11 +99,29 @@ func ApiAddr(ipfspath string) (ma.Multiaddr, error) {
 
 // NewApi constructs HttpApi with specified endpoint.
 func NewApi(a ma.Multiaddr) (*HttpApi, error) {
+	transport := &http.Transport{
+		Proxy:             http.ProxyFromEnvironment,
+		DisableKeepAlives: true,
+	}
+
+	network, address, err := manet.DialArgs(a)
+	if err != nil {
+		return nil, err
+	}
+	if network == "unix" {
+		transport.DialContext = func(_ context.Context, _, _ string) (net.Conn, error) {
+			return net.Dial("unix", address)
+		}
+		c := &http.Client{
+			Transport: transport,
+		}
+		// This will create an API client which
+		// makes requests to `http://unix`.
+		return NewURLApiWithClient(network, c)
+	}
+
 	c := &http.Client{
-		Transport: &http.Transport{
-			Proxy:             http.ProxyFromEnvironment,
-			DisableKeepAlives: true,
-		},
+		Transport: transport,
 	}
 
 	return NewApiWithClient(a, c)

cmd/ipfs/kubo/daemon.go

@@ -113,6 +113,11 @@ control your node remotely. If you need to control the node remotely,
 make sure to protect the port as you would other services or database
 (firewall, authenticated proxy, etc), or at least set API.Authorizations.
 
+If you do not want to open any ports for RPC, and only want to use
+kubo CLI client, it is possible to expose the RPC over Unix socket:
+
+  ipfs config Addresses.API /unix/var/run/kubo.socket
+
 HTTP Headers
 
 Kubo supports passing arbitrary headers to the RPC API and Gateway. You can

docs/changelogs/v0.30.md

@@ -10,6 +10,7 @@
   - [AutoNAT V2 Service Introduced Alongside V1](#autonat-v2-service-introduced-alongside-v1)
   - [Automated `ipfs version check`](#automated-ipfs-version-check)
   - [Version Suffix Configuration](#version-suffix-configuration)
+  - [`/unix/` socket support in `Addresses.API`](#unix-socket-support-in-addressesapi)
   - [Cleaned Up `ipfs daemon` Startup Log](#cleaned-up-ipfs-daemon-startup-log)
 - [📝 Changelog](#-changelog)
 - [👨‍👩‍👧‍👦 Contributors](#-contributors)
@@ -49,7 +50,24 @@ Defining the optional agent version suffix is now simpler. The [`Version.AgentSu
 
 > [!NOTE]
 > Setting a custom version suffix helps with ecosystem analysis, such as Amino DHT reports published at https://stats.ipfs.network
->
+
+#### `/unix/` socket support in `Addresses.API`
+
+This release fixes a bug which blocked users from using Unix domain sockets for [Kubo's RPC](https://docs.ipfs.tech/reference/kubo/rpc/) (instead of a local HTTP port).
+
+```console
+$ ipfs config Addresses.API "/unix/tmp/kubo.socket"
+$ ipfs daemon # start with rpc socket
+...
+RPC API server listening on /unix/tmp/kubo.socket
+
+$ # cli client, in different terminal can find socket via /api file
+$ cat $IPFS_PATH/api
+/unix/tmp/kubo.socket
+
+$ # or have it pased via --api
+$ ipfs --api=/unix/tmp/kubo.socket id
+```
 
 #### Cleaned Up `ipfs daemon` Startup Log
 

test/cli/harness/node.go

@@ -350,6 +350,17 @@ func (n *Node) checkAPI(authorization string) bool {
 		log.Debugf("node %d API addr not available yet: %s", n.ID, err.Error())
 		return false
 	}
+
+	if unixAddr, err := apiAddr.ValueForProtocol(multiaddr.P_UNIX); err == nil {
+		parts := strings.SplitN(unixAddr, "/", 2)
+		if len(parts) < 1 {
+			panic("malformed unix socket address")
+		}
+		fileName := "/" + parts[1]
+		_, err := os.Stat(fileName)
+		return !errors.Is(err, fs.ErrNotExist)
+	}
+
 	ip, err := apiAddr.ValueForProtocol(multiaddr.P_IP4)
 	if err != nil {
 		panic(err)

test/cli/rpc_unixsocket_test.go

@@ -0,0 +1,51 @@
+package cli
+
+import (
+	"context"
+	"path"
+	"testing"
+
+	rpcapi "github.com/ipfs/kubo/client/rpc"
+	"github.com/ipfs/kubo/config"
+	"github.com/ipfs/kubo/test/cli/harness"
+	"github.com/multiformats/go-multiaddr"
+	"github.com/stretchr/testify/require"
+)
+
+func TestRPCUnixSocket(t *testing.T) {
+	node := harness.NewT(t).NewNode().Init()
+
+	sockDir := node.Dir
+	sockAddr := path.Join("/unix", sockDir, "sock")
+
+	node.UpdateConfig(func(cfg *config.Config) {
+		//cfg.Addresses.API = append(cfg.Addresses.API, sockPath)
+		cfg.Addresses.API = []string{sockAddr}
+	})
+	t.Log("Starting daemon with unix socket:", sockAddr)
+	node.StartDaemon()
+
+	unixMaddr, err := multiaddr.NewMultiaddr(sockAddr)
+	require.NoError(t, err)
+
+	apiClient, err := rpcapi.NewApi(unixMaddr)
+	require.NoError(t, err)
+
+	var ver struct {
+		Version string
+	}
+	err = apiClient.Request("version").Exec(context.Background(), &ver)
+	require.NoError(t, err)
+	require.NotEmpty(t, ver)
+	t.Log("Got version:", ver.Version)
+
+	var res struct {
+		ID string
+	}
+	err = apiClient.Request("id").Exec(context.Background(), &res)
+	require.NoError(t, err)
+	require.NotEmpty(t, res)
+	t.Log("Got ID:", res.ID)
+
+	node.StopDaemon()
+}