Return error not *ErrUmbrella + add a sample app (#3)

* Add example application

.gitignore

@@ -0,0 +1 @@
+/cmd/example1/example1

Makefile

@@ -0,0 +1,23 @@
+.DEFAULT_GOAL := help
+
+.PHONY: help test
+
+test: ## Runs tests
+	go test
+
+run-example1: clean ## Runs sample app
+	@echo "* Creating docker container with PostgreSQL"
+	docker run --name umbrella-example1 -d -e POSTGRES_PASSWORD=upass -e POSTGRES_USER=uuser -e POSTGRES_DB=udb -p 54321:5432 postgres:13
+	@echo "* Sleeping for 10 seconds to give database time to initialize..."
+	@sleep 10
+	@echo "* Building and starting application..."
+	cd cmd/example1 && go build .
+	cd cmd/example1 && ./example1
+	@echo "* Removing previously created docker container..."
+
+
+clean: ## Removes all created dockers
+	docker rm -f umbrella-example1
+
+help: ## Displays this help
+	@awk 'BEGIN {FS = ":.*##"; printf "$(MAKEFILE_NAME)\n\nUsage:\n  make \033[1;36m<target>\033[0m\n\nTargets:\n"} /^[a-zA-Z0-9_-]+:.*?##/ { printf "  \033[1;36m%-25s\033[0m %s\n", $$1, $$2 }' $(MAKEFILE_LIST)

README.md

@@ -15,45 +15,26 @@ Package umbrella provides a simple authentication mechanism for an HTTP endpoint
 5. [Motivation](#motivation)
 
 ## Sample code
-The following code snippet shows how the module can be used.
-
-```go
-// database connection
-dbConn, _ = sql.Open("postgres", "host=localhost user=myuser password=mypass port=5432 dbname=mydb sslmode=disable")
-
-// umbrella controller
-u := NewUmbrella(dbConn, "tblprefix_", &JWTConfig{
-  Key: "SomeSecretKey--.",
-  Issuer: "SomeIssuer",
-  ExpirationMinutes: 15,
-}, nil)
-
-// create db tables
-_ := u.CreateDBTables()
-
-// http server
-// uri with registration, activation, login (returns auth token), logout endpoint
-http.Handle("/umbrella/", u.GetHTTPHandler("/umbrella/"))
-// restricted stuff that requires signing in (a token in http header)
-http.Handle("/restricted_stuff/", u.GetHTTPHandlerWrapper(
-  getRestrictedStuffHTTPHandler(),
-  umbrella.HandlerConfig{},
-))
-http.ListenAndServe(":8001", nil)
-
-// wrap http handler with a check for logged user
-func getRestrictedStuffHTTPHandler() http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		userID := umbrella.GetUserIDFromRequest(r)
-		if userID != 0 {
-			w.WriteHeader(http.StatusOK)
-			w.Write([]byte("RestrictedAreaContent"))
-		} else {
-			w.WriteHeader(http.StatusUnauthorized)
-			w.Write([]byte("NoAccess"))
-		}
-	})
-}
+A working application can be found in the `cmd/example1`. Type `make run-example1` to start an HTTP server and check the endpoints as shown below. jq is used to parse out the token from JSON output, however, it can be done manually as well.
+
+```bash
+# run the application
+% make run-example1
+# ...some output...
+
+# sign in to get a token
+% UMB_TOKEN=$(curl -s -X POST -d "[email protected]&password=admin" http://localhost:8001/umbrella/login | jq -r '.data.token')
+
+# call restricted endpoint without the token
+% curl http://localhost:8001/secret_stuff/ 
+YouHaveToBeLoggedIn
+
+# call it again with token
+% curl -H "Authorization: Bearer $UMB_TOKEN" http://localhost:8001/secret_stuff/
+SecretStuffOnlyForAdmin%
+
+# remove temporary postgresql docker
+make clean
 ```
 
 ## Database connection

cmd/example1/main.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"database/sql"
+	"log"
+	"net/http"
+
+	"github.com/go-phings/umbrella"
+	_ "github.com/lib/pq"
+)
+
+const dbDSN = "host=localhost user=uuser password=upass port=54321 dbname=udb sslmode=disable"
+const tblPrefix = "p_"
+
+func main() {
+	db, err := sql.Open("postgres", dbDSN)
+	if err != nil {
+		log.Fatal("Error connecting to db")
+	}
+
+	// create umbrella controller
+	u := *umbrella.NewUmbrella(db, tblPrefix, &umbrella.JWTConfig{
+		Key:               "someSecretKey",
+		Issuer:            "someIssuer",
+		ExpirationMinutes: 15,
+	}, &umbrella.UmbrellaConfig{
+		TagName:           "ui",
+	})
+
+	// create database tables
+	err = u.CreateDBTables()
+	if err != nil {
+		log.Fatalf("error creating database tables: %s", err.Error())
+	}
+
+	// create admin user
+	key, err := u.CreateUser("[email protected]", "admin", map[string]string{
+		"Name": "admin",
+	})
+	if err != nil {
+		log.Fatalf("error with creating admin: %s", err.Error())
+	}
+	err = u.ConfirmEmail(key)
+	if err != nil {
+		log.Fatalf("error with confirming admin email: %s", err.Error())
+	}
+
+	// /umbrella/{login,logout,register,confirm}
+	http.Handle("/umbrella/", u.GetHTTPHandler("/umbrella/"))
+
+	// secret stuff
+	http.Handle("/secret_stuff/", u.GetHTTPHandlerWrapper(secretStuff(), umbrella.HandlerConfig{}))
+
+	log.Fatal(http.ListenAndServe(":8001", nil))
+}
+
+func secretStuff() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		userID := umbrella.GetUserIDFromRequest(r)
+		switch userID {
+		case 1: 
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte("SecretStuffOnlyForAdmin"))
+		case 0:
+			w.WriteHeader(http.StatusUnauthorized)
+			w.Write([]byte("YouHaveToBeLoggedIn"))
+		default:
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte("SecretStuffForOtherUser"))
+		}
+	})
+}

err.go

@@ -7,10 +7,10 @@ type ErrUmbrella struct {
 	Err error
 }
 
-func (e *ErrUmbrella) Error() string {
+func (e ErrUmbrella) Error() string {
 	return e.Err.Error()
 }
 
-func (e *ErrUmbrella) Unwrap() error {
+func (e ErrUmbrella) Unwrap() error {
 	return e.Err
 }