Fix #1366: IPFS Proxy API serializes wrong error types

The errors returned by the IPFS Proxy API are not understood by IPFS.

This was caused by go-ipfs-cmds setting an API error format which requires the
errors to have a type: "error" field.

This commit brings this up to speed.

api/ipfsproxy/ipfsproxy.go

@@ -22,6 +22,7 @@ import (
 	handlers "github.com/gorilla/handlers"
 	mux "github.com/gorilla/mux"
 	cid "github.com/ipfs/go-cid"
+	cmd "github.com/ipfs/go-ipfs-cmds"
 	logging "github.com/ipfs/go-log/v2"
 	path "github.com/ipfs/go-path"
 	peer "github.com/libp2p/go-libp2p-core/peer"
@@ -69,10 +70,6 @@ type Server struct {
 	wg           sync.WaitGroup
 }
 
-type ipfsError struct {
-	Message string
-}
-
 type ipfsPinType struct {
 	Type string
 }
@@ -332,7 +329,8 @@ func (proxy *Server) run() {
 
 // ipfsErrorResponder writes an http error response just like IPFS would.
 func ipfsErrorResponder(w http.ResponseWriter, errMsg string, code int) {
-	res := ipfsError{errMsg}
+	res := cmd.Errorf(cmd.ErrNormal, errMsg)
+
 	resBytes, _ := json.Marshal(res)
 	if code > 0 {
 		w.WriteHeader(code)

go.mod

@@ -24,6 +24,7 @@ require (
 	github.com/ipfs/go-fs-lock v0.0.6
 	github.com/ipfs/go-ipfs-api v0.2.0
 	github.com/ipfs/go-ipfs-chunker v0.0.5
+	github.com/ipfs/go-ipfs-cmds v0.6.0
 	github.com/ipfs/go-ipfs-config v0.12.0
 	github.com/ipfs/go-ipfs-ds-help v1.0.0
 	github.com/ipfs/go-ipfs-files v0.0.8

go.sum

@@ -429,6 +429,8 @@ github.com/ipfs/go-ipfs-blocksutil v0.0.1/go.mod h1:Yq4M86uIOmxmGPUHv/uI7uKqZNtL
 github.com/ipfs/go-ipfs-chunker v0.0.1/go.mod h1:tWewYK0we3+rMbOh7pPFGDyypCtvGcBFymgY4rSDLAw=
 github.com/ipfs/go-ipfs-chunker v0.0.5 h1:ojCf7HV/m+uS2vhUGWcogIIxiO5ubl5O57Q7NapWLY8=
 github.com/ipfs/go-ipfs-chunker v0.0.5/go.mod h1:jhgdF8vxRHycr00k13FM8Y0E+6BoalYeobXmUyTreP8=
+github.com/ipfs/go-ipfs-cmds v0.6.0 h1:yAxdowQZzoFKjcLI08sXVNnqVj3jnABbf9smrPQmBsw=
+github.com/ipfs/go-ipfs-cmds v0.6.0/go.mod h1:ZgYiWVnCk43ChwoH8hAmI1IRbuVtq3GSTHwtRB/Kqhk=
 github.com/ipfs/go-ipfs-config v0.12.0 h1:wxqN3ohBlis1EkhkzIKuF+XLx4YNn9rNpiSOYw3DFZc=
 github.com/ipfs/go-ipfs-config v0.12.0/go.mod h1:Ei/FLgHGTdPyqCPK0oPCwGTe8VSnsjJjx7HZqUb6Ry0=
 github.com/ipfs/go-ipfs-delay v0.0.0-20181109222059-70721b86a9a8/go.mod h1:8SP1YXK1M1kXuc4KJZINY3TQQ03J2rwBG9QfXmbRPrw=
@@ -1171,6 +1173,7 @@ github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/syndtr/goleveldb v1.0.0 h1:fBdIW9lB4Iz0n9khmH8w27SJ3QEJ7+IgjPEwGSZiFdE=
 github.com/syndtr/goleveldb v1.0.0/go.mod h1:ZVVdQEZoIme9iO1Ch2Jdy24qqXrMMOU6lpPAyBWyWuQ=
 github.com/tarm/serial v0.0.0-20180830185346-98f6abe2eb07/go.mod h1:kDXzergiv9cbyO7IOYJZWg1U88JhDg3PB6klq9Hg2pA=
+github.com/texttheater/golang-levenshtein v0.0.0-20180516184445-d188e65d659e/go.mod h1:XDKHRm5ThF8YJjx001LtgelzsoaEcvnA7lVWz9EeX3g=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20170815181823-89b8d40f7ca8/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/tv42/httpunix v0.0.0-20150427012821-b75d8614f926 h1:G3dpKMzFDjgEh2q1Z7zUUtKa8ViPtH+ocF0bE0g00O8=
 github.com/tv42/httpunix v0.0.0-20150427012821-b75d8614f926/go.mod h1:9ESjWnEqriFuLhtthL60Sar/7RFoluCcXsuvEwTV5KM=
@@ -1278,6 +1281,7 @@ golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8/go.mod h1:yigFU9vqHzYiE8U
 golang.org/x/crypto v0.0.0-20190618222545-ea8f1a30c443/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200115085410-6d4e4cb37c7d/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200117160349-530e935923ad/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200221231518-2aa609cf4a9d/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200423211502-4bdfaf469ed5/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=