add useful error when API URL not set

README-cn.md

@@ -21,7 +21,6 @@
 
 ```bash
 go get -u -v github.com/eoscanada/eosc/eosc
-
 ```
 
 

README.md

@@ -306,7 +306,6 @@ place.
 
 
 ## Cryptographic primitives used
------------------------------
 
 The cryptography used is NaCl
 ([C implementation](https://tweetnacl.cr.yp.to/), [Javascript port](https://github.com/dchest/tweetnacl-js),

eosc/cmd/common.go

@@ -154,6 +154,9 @@ func sanitizeAPIURL(input string) string {
 func errorCheck(prefix string, err error) {
 	if err != nil {
 		fmt.Printf("ERROR: %s: %s\n", prefix, err)
+		if strings.HasSuffix(err.Error(), "connection refused") && strings.Contains(err.Error(), defaultAPIURL) {
+			fmt.Println("Have you selected a valid EOS HTTP endpoint ? You can use the --api-url flag or EOSC_GLOBAL_API_URL environment variable.")
+		}
 		os.Exit(1)
 	}
 }

eosc/cmd/root.go

@@ -15,6 +15,8 @@ import (
 // Version represents the eosc command version
 var Version string
 
+const defaultAPIURL = "http://localhost:8888"
+
 // RootCmd represents the eosc command
 var RootCmd = &cobra.Command{
 	Use:   "eosc",
@@ -47,7 +49,7 @@ func init() {
 	RootCmd.PersistentFlags().BoolP("debug", "", false, "Enables verbose API debug messages")
 	RootCmd.PersistentFlags().StringP("vault-file", "", "./eosc-vault.json", "Wallet file that contains encrypted key material")
 	RootCmd.PersistentFlags().StringSliceP("wallet-url", "", []string{}, "Base URL to wallet endpoint. You can pass this multiple times to use the multi-signer (will use each wallet to sign multi-sig transactions).")
-	RootCmd.PersistentFlags().StringP("api-url", "u", "http://localhost:8888", "API endpoint of eos.io blockchain node")
+	RootCmd.PersistentFlags().StringP("api-url", "u", defaultAPIURL, "API endpoint of eos.io blockchain node")
 	RootCmd.PersistentFlags().StringSliceP("permission", "p", []string{}, "Permission to sign transactions with. Optionally specify more than one, or separate by comma")
 	RootCmd.PersistentFlags().StringSliceP("http-header", "H", []string{}, "HTTP header to add to a request. Optionally repeat this option to specify multiple headers")
 	RootCmd.PersistentFlags().StringP("kms-gcp-keypath", "", "", "Path to the cryptoKeys within a keyRing on GCP")