WIP DNS resolution for API endpoint on ipfs bin (#5249)

License: MIT
Signed-off-by: Raúl Kripalani <raul.kripalani@consensys.net>

cmd/ipfs/main.go

@@ -34,6 +34,7 @@ import (
 	osh "gx/ipfs/QmXuBJ7DR6k3rmUEKtvVMhwjmXDuJgXXPUt4LQXKBMsU93/go-os-helper"
 	ma "gx/ipfs/QmYmsdtJ3HsodkePE3eU3TsCaP2YvPZJ4LoXnNkDE5Tpt7/go-multiaddr"
 	loggables "gx/ipfs/QmZ4zF1mBrt8C2mSCM4ZYE4aAnv78f7GvrzufJC4G5tecK/go-libp2p-loggables"
+	mdns "gx/ipfs/QmfXU2MhWoegxHoeMd3A2ytL2P6CY4FfqGWc23LTNWBwZt/go-multiaddr-dns"
 )
 
 // log is the command logger
@@ -235,7 +236,7 @@ func commandShouldRunOnDaemon(details cmdDetails, req *cmds.Request, cctx *oldcm
 	// did user specify an api to use for this command?
 	apiAddrStr, _ := req.Options[corecmds.ApiOption].(string)
 
-	client, err := getApiClient(cctx.ConfigRoot, apiAddrStr)
+	client, err := getApiClient(req.Context, cctx.ConfigRoot, apiAddrStr)
 	if err == repo.ErrApiNotRunning {
 		if apiAddrStr != "" && req.Command != daemonCmd {
 			// if user SPECIFIED an api, and this cmd is not daemon
@@ -406,7 +407,7 @@ var checkIPFSWinFmt = "Otherwise check:\n\ttasklist | findstr ipfs"
 // getApiClient checks the repo, and the given options, checking for
 // a running API service. if there is one, it returns a client.
 // otherwise, it returns errApiNotRunning, or another error.
-func getApiClient(repoPath, apiAddrStr string) (http.Client, error) {
+func getApiClient(ctx context.Context, repoPath, apiAddrStr string) (http.Client, error) {
 	var apiErrorFmt string
 	switch {
 	case osh.IsUnix():
@@ -440,14 +441,34 @@ func getApiClient(repoPath, apiAddrStr string) (http.Client, error) {
 	if len(addr.Protocols()) == 0 {
 		return nil, fmt.Errorf(apiErrorFmt, repoPath, "multiaddr doesn't provide any protocols")
 	}
-	return apiClientForAddr(addr)
+	return apiClientForAddr(ctx, addr)
 }
 
-func apiClientForAddr(addr ma.Multiaddr) (http.Client, error) {
-	_, host, err := manet.DialArgs(addr)
+func apiClientForAddr(ctx context.Context, addr ma.Multiaddr) (http.Client, error) {
+	addrs, err := mdns.Resolve(ctx, addr)
 	if err != nil {
 		return nil, err
 	}
 
-	return http.NewClient(host, http.ClientWithAPIPrefix(corehttp.APIPath)), nil
+	dialer := &manet.Dialer{}
+	for _, addr := range addrs {
+		ctx, cancelFunc := context.WithTimeout(ctx, 5*time.Second)
+		defer cancelFunc()
+
+		conn, err := dialer.DialContext(ctx, addr)
+		if err != nil {
+			log.Errorf("connection to %s failed, error: %s", addr, err)
+			continue
+		}
+		conn.Close()
+
+		_, host, err := manet.DialArgs(addr)
+		if err != nil {
+			continue
+		}
+
+		return http.NewClient(host, http.ClientWithAPIPrefix(corehttp.APIPath)), nil
+	}
+
+	return nil, errors.New("non-resolvable API endpoint")
 }

package.json

@@ -539,6 +539,12 @@
       "hash": "QmPyxJ2QS7L5FhGkNYkNcXHGjDhvGHueJ4auqAstFHYxy5",
       "name": "go-cidutil",
       "version": "0.0.2"
+    },
+    {
+      "author": "lgierth",
+      "hash": "QmfXU2MhWoegxHoeMd3A2ytL2P6CY4FfqGWc23LTNWBwZt",
+      "name": "go-multiaddr-dns",
+      "version": "0.2.4"
     }
   ],
   "gxVersion": "0.10.0",