client/rest, modules/coin/rest: moved code around

After offline emails and a video call with @ethanfrey,
a goal was decided to move things around i.e:
- [X] Move /build/send and /query/account to modules/coin/rest

Due to that move, there is a lot of overlap between needed
code and utils so extracted common code to make
https://github.com/tendermint/tmlibs/pull/33
so make sure to pull in that commit into your tmlibs tree.

After code review feedback:
client/rest, modules/coin/rest: FoutputProof, PrepareSendTx helper

* Extract OutputProof to FoutputProof helper that can
be used in modules/coin/rest/handlers.go as proofs.FoutputProof
* Revert r.HandleFunc("/tx", doPostTx).Methods("POST") which
was erraneously deleted
* Use function signatures from "tendermint/tmblibs/common"

client/commands/proofs/get.go

@@ -2,6 +2,8 @@ package proofs
 
 import (
 	"fmt"
+	"io"
+	"os"
 
 	"github.com/pkg/errors"
 	"github.com/spf13/viper"
@@ -111,15 +113,22 @@ type proof struct {
 	Data   interface{} `json:"data"`
 }
 
-// OutputProof prints the proof to stdout
-// reuse this for printing proofs and we should enhance this for text/json,
-// better presentation of height
-func OutputProof(info interface{}, height uint64) error {
-	wrap := proof{height, info}
-	res, err := data.ToJSON(wrap)
+// FoutputProof writes the output of wrapping height and info
+// in the form {"data": <the_data>, "height": <the_height>}
+// to the provider io.Writer
+func FoutputProof(w io.Writer, v interface{}, height uint64) error {
+	wrap := &proof{height, v}
+	blob, err := data.ToJSON(wrap)
 	if err != nil {
 		return err
 	}
-	fmt.Println(string(res))
-	return nil
+	_, err = fmt.Fprintf(w, "%s\n", blob)
+	return err
+}
+
+// OutputProof prints the proof to stdout
+// reuse this for printing proofs and we should enhance this for text/json,
+// better presentation of height
+func OutputProof(data interface{}, height uint64) error {
+	return FoutputProof(os.Stdout, data, height)
 }

client/rest/cmd.go

@@ -0,0 +1,47 @@
+package rest
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+
+	"github.com/gorilla/mux"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+
+	coinrest "github.com/tendermint/basecoin/modules/coin/rest"
+)
+
+var ServeCmd = &cobra.Command{
+	Use:   "serve",
+	Short: "Serve the light REST client for tendermint",
+	Long:  "Access basecoin via REST",
+	RunE:  serve,
+}
+
+const envPortFlag = "port"
+
+func init() {
+	_ = ServeCmd.PersistentFlags().Int(envPortFlag, 8998, "the port to run the server on")
+}
+
+const defaultAlgo = "ed25519"
+
+func serve(cmd *cobra.Command, args []string) error {
+	port := viper.GetInt(envPortFlag)
+	keysManager := DefaultKeysManager()
+	router := mux.NewRouter()
+	ctx := Context{
+		Keys: New(keysManager, defaultAlgo),
+	}
+	if err := ctx.RegisterHandlers(router); err != nil {
+		return err
+	}
+	if err := coinrest.RegisterHandlers(router); err != nil {
+		return err
+	}
+
+	addr := fmt.Sprintf(":%d", port)
+	log.Printf("Serving on %q", addr)
+	return http.ListenAndServe(addr, router)
+}

client/rest/handlers.go

@@ -1,25 +1,15 @@
 package rest
 
 import (
-	"fmt"
 	"net/http"
-	"strings"
 
 	"github.com/gorilla/mux"
 	"github.com/pkg/errors"
 
 	"github.com/tendermint/basecoin"
-	"github.com/tendermint/basecoin/client/commands"
-	"github.com/tendermint/basecoin/client/commands/proofs"
-	"github.com/tendermint/basecoin/modules/auth"
-	"github.com/tendermint/basecoin/modules/base"
-	"github.com/tendermint/basecoin/modules/coin"
-	"github.com/tendermint/basecoin/modules/fee"
-	"github.com/tendermint/basecoin/modules/nonce"
-	"github.com/tendermint/basecoin/stack"
 	keysutils "github.com/tendermint/go-crypto/cmd"
 	keys "github.com/tendermint/go-crypto/keys"
-	lightclient "github.com/tendermint/light-client"
+	"github.com/tendermint/tmlibs/common"
 )
 
 type Keys struct {
@@ -42,19 +32,19 @@ func (k *Keys) GenerateKey(w http.ResponseWriter, r *http.Request) {
 	ckReq := &CreateKeyRequest{
 		Algo: k.algo,
 	}
-	if err := parseRequestJSON(r, ckReq); err != nil {
-		writeError(w, err)
+	if err := common.ParseRequestAndValidateJSON(r, ckReq); err != nil {
+		common.WriteError(w, err)
 		return
 	}
 
 	key, seed, err := k.manager.Create(ckReq.Name, ckReq.Passphrase, ckReq.Algo)
 	if err != nil {
-		writeError(w, err)
+		common.WriteError(w, err)
 		return
 	}
 
 	res := &CreateKeyResponse{Key: key, Seed: seed}
-	writeSuccess(w, res)
+	common.WriteSuccess(w, res)
 }
 
 func (k *Keys) GetKey(w http.ResponseWriter, r *http.Request) {
@@ -62,19 +52,19 @@ func (k *Keys) GetKey(w http.ResponseWriter, r *http.Request) {
 	name := query["name"]
 	key, err := k.manager.Get(name)
 	if err != nil {
-		writeError(w, err)
+		common.WriteError(w, err)
 		return
 	}
-	writeSuccess(w, &key)
+	common.WriteSuccess(w, &key)
 }
 
 func (k *Keys) ListKeys(w http.ResponseWriter, r *http.Request) {
 	keys, err := k.manager.List()
 	if err != nil {
-		writeError(w, err)
+		common.WriteError(w, err)
 		return
 	}
-	writeSuccess(w, keys)
+	common.WriteSuccess(w, keys)
 }
 
 var (
@@ -83,52 +73,52 @@ var (
 
 func (k *Keys) UpdateKey(w http.ResponseWriter, r *http.Request) {
 	uReq := new(UpdateKeyRequest)
-	if err := parseRequestJSON(r, uReq); err != nil {
-		writeError(w, err)
+	if err := common.ParseRequestAndValidateJSON(r, uReq); err != nil {
+		common.WriteError(w, err)
 		return
 	}
 
 	query := mux.Vars(r)
 	name := query["name"]
 	if name != uReq.Name {
-		writeError(w, errNonMatchingPathAndJSONKeyNames)
+		common.WriteError(w, errNonMatchingPathAndJSONKeyNames)
 		return
 	}
 
 	if err := k.manager.Update(uReq.Name, uReq.OldPass, uReq.NewPass); err != nil {
-		writeError(w, err)
+		common.WriteError(w, err)
 		return
 	}
 
 	key, err := k.manager.Get(uReq.Name)
 	if err != nil {
-		writeError(w, err)
+		common.WriteError(w, err)
 		return
 	}
-	writeSuccess(w, &key)
+	common.WriteSuccess(w, &key)
 }
 
 func (k *Keys) DeleteKey(w http.ResponseWriter, r *http.Request) {
 	dReq := new(DeleteKeyRequest)
-	if err := parseRequestJSON(r, dReq); err != nil {
-		writeError(w, err)
+	if err := common.ParseRequestAndValidateJSON(r, dReq); err != nil {
+		common.WriteError(w, err)
 		return
 	}
 
 	query := mux.Vars(r)
 	name := query["name"]
 	if name != dReq.Name {
-		writeError(w, errNonMatchingPathAndJSONKeyNames)
+		common.WriteError(w, errNonMatchingPathAndJSONKeyNames)
 		return
 	}
 
 	if err := k.manager.Delete(dReq.Name, dReq.Passphrase); err != nil {
-		writeError(w, err)
+		common.WriteError(w, err)
 		return
 	}
 
-	resp := &ErrorResponse{Success: true}
-	writeSuccess(w, resp)
+	resp := &common.ErrorResponse{Success: true}
+	common.WriteSuccess(w, resp)
 }
 
 func (k *Keys) Register(r *mux.Router) {
@@ -145,140 +135,38 @@ type Context struct {
 
 func (ctx *Context) RegisterHandlers(r *mux.Router) error {
 	ctx.Keys.Register(r)
-	r.HandleFunc("/build/send", doSend).Methods("POST")
 	r.HandleFunc("/sign", doSign).Methods("POST")
 	r.HandleFunc("/tx", doPostTx).Methods("POST")
-	r.HandleFunc("/query/account/{signature}", doAccountQuery).Methods("GET")
 
 	return nil
 }
 
-func extractAddress(signature string) (address string, err *ErrorResponse) {
-	// Expecting the signature of the form:
-	//  sig:<ADDRESS>
-	splits := strings.Split(signature, ":")
-	if len(splits) < 2 {
-		return "", &ErrorResponse{
-			Error: `expecting the signature of the form "sig:<ADDRESS>"`,
-			Code:  406,
-		}
-	}
-	if splits[0] != "sigs" {
-		return "", &ErrorResponse{
-			Error: `expecting the signature of the form "sig:<ADDRESS>"`,
-			Code:  406,
-		}
-	}
-	return splits[1], nil
-}
-
-func doAccountQuery(w http.ResponseWriter, r *http.Request) {
-	query := mux.Vars(r)
-	signature := query["signature"]
-	address, errResp := extractAddress(signature)
-	if errResp != nil {
-		writeCode(w, errResp, errResp.Code)
-		return
-	}
-	actor, err := commands.ParseActor(address)
-	if err != nil {
-		writeError(w, err)
-		return
-	}
-	actor = coin.ChainAddr(actor)
-	key := stack.PrefixedKey(coin.NameCoin, actor.Bytes())
-	account := new(coin.Account)
-	proof, err := proofs.GetAndParseAppProof(key, account)
-	if lightclient.IsNoDataErr(err) {
-		err := fmt.Errorf("account bytes are empty for address: %q", address)
-		writeError(w, err)
-		return
-	} else if err != nil {
-		writeError(w, err)
-		return
-	}
-
-	if err := proofs.OutputProof(account, proof.BlockHeight()); err != nil {
-		writeError(w, err)
-		return
-	}
-	writeSuccess(w, account)
-}
-
 func doPostTx(w http.ResponseWriter, r *http.Request) {
 	tx := new(basecoin.Tx)
-	if err := parseRequestJSON(r, tx); err != nil {
-		writeError(w, err)
+	if err := common.ParseRequestAndValidateJSON(r, tx); err != nil {
+		common.WriteError(w, err)
 		return
 	}
 	commit, err := PostTx(*tx)
 	if err != nil {
-		writeError(w, err)
+		common.WriteError(w, err)
 		return
 	}
 
-	writeSuccess(w, commit)
+	common.WriteSuccess(w, commit)
 }
 
 func doSign(w http.ResponseWriter, r *http.Request) {
 	sr := new(SignRequest)
-	if err := parseRequestJSON(r, sr); err != nil {
-		writeError(w, err)
+	if err := common.ParseRequestAndValidateJSON(r, sr); err != nil {
+		common.WriteError(w, err)
 		return
 	}
 
 	tx := sr.Tx
 	if err := SignTx(sr.Name, sr.Password, tx); err != nil {
-		writeError(w, err)
+		common.WriteError(w, err)
 		return
 	}
-	writeSuccess(w, tx)
-}
-
-func doSend(w http.ResponseWriter, r *http.Request) {
-	defer r.Body.Close()
-	si := new(SendInput)
-	if err := parseRequestJSON(r, si); err != nil {
-		writeError(w, err)
-		return
-	}
-
-	var errsList []string
-	if si.From == nil {
-		errsList = append(errsList, `"from" cannot be nil`)
-	}
-	if si.Sequence <= 0 {
-		errsList = append(errsList, `"sequence" must be > 0`)
-	}
-	if si.To == nil {
-		errsList = append(errsList, `"to" cannot be nil`)
-	}
-	if len(si.Amount) == 0 {
-		errsList = append(errsList, `"amount" cannot be empty`)
-	}
-	if len(errsList) > 0 {
-		err := &ErrorResponse{
-			Error: strings.Join(errsList, ", "),
-			Code:  406,
-		}
-		writeCode(w, err, 406)
-		return
-	}
-
-	tx := coin.NewSendOneTx(*si.From, *si.To, si.Amount)
-	// fees are optional
-	if si.Fees != nil && !si.Fees.IsZero() {
-		tx = fee.NewFee(tx, *si.Fees, *si.From)
-	}
-	// only add the actual signer to the nonce
-	signers := []basecoin.Actor{*si.From}
-	tx = nonce.NewTx(si.Sequence, signers, tx)
-	tx = base.NewChainTx(commands.GetChainID(), 0, tx)
-
-	if si.Multi {
-		tx = auth.NewMulti(tx).Wrap()
-	} else {
-		tx = auth.NewSig(tx).Wrap()
-	}
-	writeSuccess(w, tx)
+	common.WriteSuccess(w, tx)
 }

client/rest/types.go

@@ -1,17 +1,9 @@
 package rest
 
 import (
-	"encoding/json"
-	"io/ioutil"
-	"net/http"
-
-	"github.com/pkg/errors"
-	"gopkg.in/go-playground/validator.v9"
-
 	"github.com/tendermint/basecoin"
 	"github.com/tendermint/basecoin/modules/coin"
 	"github.com/tendermint/go-crypto/keys"
-	data "github.com/tendermint/go-wire/data"
 )
 
 type CreateKeyRequest struct {
@@ -40,16 +32,6 @@ type SignRequest struct {
 	Tx basecoin.Tx `json:"tx" validate:"required"`
 }
 
-type ErrorResponse struct {
-	Success bool `json:"success,omitempty"`
-
-	// Error is the error message if Success is false
-	Error string `json:"error,omitempty"`
-
-	// Code is set if Success is false
-	Code int `json:"code,omitempty"`
-}
-
 type CreateKeyResponse struct {
 	Key  keys.Info `json:"key,omitempty"`
 	Seed string    `json:"seed_phrase,omitempty"`
@@ -68,48 +50,3 @@ type SendInput struct {
 	From   *basecoin.Actor `json:"from"`
 	Amount coin.Coins      `json:"amount"`
 }
-
-// Validators
-
-var theValidator = validator.New()
-
-func validate(req interface{}) error {
-	return errors.Wrap(theValidator.Struct(req), "Validate")
-}
-
-// Helpers
-func parseRequestJSON(r *http.Request, save interface{}) error {
-	defer r.Body.Close()
-
-	slurp, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		return errors.Wrap(err, "Read Request")
-	}
-	if err := json.Unmarshal(slurp, save); err != nil {
-		return errors.Wrap(err, "Parse")
-	}
-	return validate(save)
-}
-
-func writeSuccess(w http.ResponseWriter, data interface{}) {
-	writeCode(w, data, 200)
-}
-
-func writeCode(w http.ResponseWriter, out interface{}, code int) {
-	blob, err := data.ToJSON(out)
-	if err != nil {
-		writeError(w, err)
-	} else {
-		w.Header().Set("Content-Type", "application/json")
-		w.WriteHeader(code)
-		w.Write(blob)
-	}
-}
-
-func writeError(w http.ResponseWriter, err error) {
-	resp := &ErrorResponse{
-		Code:  406,
-		Error: err.Error(),
-	}
-	writeCode(w, resp, 406)
-}