Skip security-proxy runtime config options on deferred startup (#25)

This change disables the application of the following config options
in defer-startup install mode to be applied separately after the setup 
of security-proxy:
* env.security-proxy.user
* env.security-proxy.public-key
* env.security-proxy.tls-certificate
* env.security-proxy.tls-private-key
* env.security-proxy.tls-sni

This is change is coupled with edgexfoundry/edgex-go#3856

utils.go

@@ -643,6 +643,8 @@ func HandleEdgeXConfig(service, envJSON string, extraConf map[string]string) err
 		// This uses the standard naming schema but doesn't actually use environment variables
 		if service == "security-proxy" {
 			value := strings.TrimSpace(v)
+			// These config options are read and validated in the loop,
+			// but handled collectively afterwards
 			switch k {
 			case "user":
 				if value != "" {
@@ -695,35 +697,45 @@ func HandleEdgeXConfig(service, envJSON string, extraConf map[string]string) err
 		}
 	}
 
-	// Handle security-* service naming. The service names in this
-	// hook historically do not align with the actual binary commands.
-	// As such, when handling configuration settings for them, we need
-	// to translate the hook name to the actual binary name.
-	if service == "security-proxy" {
-		service = "security-proxy-setup"
+	// install-mode is set in the install hook of edgexfoundry
+	installMode, err := NewSnapCtl().Config("install-mode")
+	if err != nil {
+		return fmt.Errorf("failed to read 'install-mode': %s", err)
+	}
 
-		if jwtUsername == "" && jwtPublicKey == "" {
-			// if the values have been set to "" then delete the current user
-			securityProxyDeleteCurrentUserIfSet()
-		} else if jwtUsername != "" && jwtPublicKey != "" {
-			// else add a new user
-			err = securityProxyAddUser(jwtUsername, jwtUserID, jwtAlgorithm, jwtPublicKey)
-			if err != nil {
-				return err
+	// post-startup config handling
+	if installMode != "defer-startup" {
+		if service == "security-proxy" {
+			if jwtUsername == "" && jwtPublicKey == "" {
+				// if the values have been set to "" then delete the current user
+				securityProxyDeleteCurrentUserIfSet()
+			} else if jwtUsername != "" && jwtPublicKey != "" {
+				// else add a new user
+				err = securityProxyAddUser(jwtUsername, jwtUserID, jwtAlgorithm, jwtPublicKey)
+				if err != nil {
+					return err
+				}
 			}
-		}
 
-		if tlsCertificate == "" && tlsPrivateKey == "" {
-			// if the values have been set to "" then clear the semaphore so that a new cert can be set
-			securityProxyDeleteCurrentTLSCertIfSet()
-		} else if tlsCertificate != "" && tlsPrivateKey != "" {
-			// Set the TLS certificate and private key
-			err = securityProxySetTLSCertificate(tlsCertificate, tlsPrivateKey, tlsSNI)
-			if err != nil {
-				return err
+			if tlsCertificate == "" && tlsPrivateKey == "" {
+				// if the values have been set to "" then clear the semaphore so that a new cert can be set
+				securityProxyDeleteCurrentTLSCertIfSet()
+			} else if tlsCertificate != "" && tlsPrivateKey != "" {
+				// Set the TLS certificate and private key
+				err = securityProxySetTLSCertificate(tlsCertificate, tlsPrivateKey, tlsSNI)
+				if err != nil {
+					return err
+				}
 			}
 		}
+	}
 
+	// Handle security-* service naming. The service names in this
+	// hook historically do not align with the actual binary commands.
+	// As such, when handling configuration settings for them, we need
+	// to translate the hook name to the actual binary name.
+	if service == "security-proxy" {
+		service = "security-proxy-setup"
 	} else if service == "security-secret-store" {
 		service = "security-secretstore-setup"
 	}