Implement swagger docs and fix path validation

Makefile

@@ -98,3 +98,10 @@ build-wasmd:
 delete-chains: 
 	@echo "Removing the ./chain-code/ directory..."
 	@rm -rf ./chain-code
+
+check-swagger:
+	which swagger || (GO111MODULE=off go get -u github.com/go-swagger/go-swagger/cmd/swagger)
+
+update-swagger-docs: check-swagger
+	swagger generate spec -o ./docs/swagger-ui/swagger.yaml
+

cmd/api.go

@@ -168,11 +168,15 @@ func getAPICmd() *cobra.Command {
 			// Data for this should be stored in the ServicesManager struct
 			r.HandleFunc("/listen/{path}/{strategy}/{name}", PostRelayerListenHandler(sm)).Methods("POST")
 
+			fs := http.FileServer(http.Dir("./docs/swagger-ui"))
+			r.PathPrefix("/").Handler(fs)
+
+			fmt.Println("listening on", config.Global.APIListenPort)
+
 			if err := http.ListenAndServe(config.Global.APIListenPort, r); err != nil {
 				return err
 			}
 
-			fmt.Println("listening on", config.Global.APIListenPort)
 			return nil
 		},
 	}

cmd/chains.go

@@ -546,8 +546,10 @@ type addChainRequest struct {
 	GasAdjustment  string `json:"gas-adjustment"`
 	GasPrices      string `json:"gas-prices"`
 	TrustingPeriod string `json:"trusting-period"`
-	FilePath       string `json:"file"`
-	URL            string `json:"url"`
+	// required: false
+	FilePath string `json:"file"`
+	// required: false
+	URL string `json:"url"`
 }
 
 // PostChainHandler handles the route
@@ -678,6 +680,11 @@ func PutChainHandler(w http.ResponseWriter, r *http.Request) {
 // DeleteChainHandler handles the route
 func DeleteChainHandler(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
+	_, err := config.Chains.Get(vars["name"])
+	if err != nil {
+		helpers.WriteErrorResponse(http.StatusBadRequest, err, w)
+		return
+	}
 	if err := overWriteConfig(config.DeleteChain(vars["name"])); err != nil {
 		helpers.WriteErrorResponse(http.StatusInternalServerError, err, w)
 		return

cmd/config.go

@@ -564,15 +564,16 @@ func (c *Config) ValidatePathEnd(pe *relayer.PathEnd) error {
 		return err
 	}
 
+	chain, err := c.Chains.Get(pe.ChainID)
+	if err != nil {
+		return err
+	}
+
 	// if the identifiers are empty, don't do any validation
 	if pe.ClientID == "" && pe.ConnectionID == "" && pe.ChannelID == "" {
 		return nil
 	}
 
-	chain, err := c.Chains.Get(pe.ChainID)
-	if err != nil {
-		return err
-	}
 	// NOTE: this is just to do validation, the path
 	// is not written to the config file
 	if err = chain.SetPath(pe); err != nil {