Update comments

config.go

@@ -6,7 +6,7 @@ import (
 )
 
 // config accepts a slice of type Redirect and returns an error
-// it organizes the data from the input redirects in a way that makes sense for FortiOS objects
+// it organizes the input data in a way that makes sense for FortiOS objects
 // then outputs the configuration to stdout
 func config(redirects []Redirect) error {
 
@@ -16,16 +16,18 @@ func config(redirects []Redirect) error {
 
 	// Iterate over all redirects and output url-rewrite-rules
 
-	fmt.Printf("\n\n------------------------\n\n\n")
+	fmt.Printf("\n\n------------------------ COPY BELOW THIS LINE ------------------------\n\n\n")
 	fmt.Println("config waf url-rewrite url-rewrite-rule")
 	for _, redirect := range redirects {
+
+		// Parse the source URL string into a URL object so we can extract features
 		sourceURL, err := url.Parse(redirect.sourceURL)
 		if err != nil {
 			return fmt.Errorf("unable to parse source URL '%s': %v", redirect.sourceURL, err)
 		}
 
 		var ruleName, action string
-		if len(redirect.sourceURL) > 63 { // FortiOS only allows up to 63 characters
+		if len(redirect.sourceURL) > 63 { // FortiOS only allows up to 63 characters.  There is potention for collission here.  TBD: Reduce and replace characters in the middle of string with '...' and show characters at the end of the URL to make differentiation easier for operators of the WAF
 			ruleName = redirect.sourceURL[:62]
 		} else {
 			ruleName = redirect.sourceURL
@@ -37,6 +39,7 @@ func config(redirects []Redirect) error {
 			action = "redirect"
 		}
 
+		// Output FortiOS configuration syntax
 		fmt.Printf("edit \"%s\"\n", ruleName)
 		fmt.Printf("set location %s\n", redirect.destinationURL)
 		fmt.Printf("set action %s\n", action)
@@ -50,11 +53,12 @@ func config(redirects []Redirect) error {
 		fmt.Println("end")
 		fmt.Println("next")
 
-		// Add this rule to the policy map
+		// Add this rule to the slice inside the policy map.  This is used to organize data for creating the url-rewrite-policy configuration below
 		redirectPolicies[sourceURL.Host] = append(redirectPolicies[sourceURL.Host], ruleName)
 	}
 	fmt.Println("end")
 
+	// Output url-rewrite-policy configuration.
 	// Iterate over values in the policy map and output the policy configuration
 	fmt.Println("config waf url-rewrite url-rewrite-policy")
 	for policyName, policyRules := range redirectPolicies {
@@ -68,7 +72,7 @@ func config(redirects []Redirect) error {
 		fmt.Println("end")
 		fmt.Println("next")
 	}
-	fmt.Println("end")
+	fmt.Printf("end\n\n\n")
 
 	return nil
 }

main.go

@@ -64,12 +64,12 @@ func main() {
 
 	// Determine the next steps
 	if *action == "config" {
-		err := config(redirects)
+		err := config(redirects) // Function defined in config.go
 		if err != nil {
 			log.Fatalf("failed to build configuration: %v", err)
 		}
 	} else if *action == "test" {
-		err := test(redirects)
+		err := test(redirects) // Function defined in test.go
 		if err != nil {
 			log.Fatalf("failed to test redirects: %v", err)
 		}

test.go

@@ -12,21 +12,28 @@ var sem chan Empty // semaphore to limit requess in flight
 // test accepts a slice of type Redirect and returns an error
 // it performs actual HTTP GET requests on each source URL and validates that a redirect occurs
 // to the destination URL and that the redirect type/status code is correct
+// This function makes use of concurrent requests to speed up testing.
 func test(redirects []Redirect) error {
 
-	wg := &sync.WaitGroup{}
-	mu := &sync.Mutex{}
+	// This string will hold output for any failed tests.  It's displayed when all tests have completed
 	var summaryOutput string
 
-	sem = make(Semaphore, *maxConcurrentRequests)
+	// Set up some tools to handle concurrency
+	wg := &sync.WaitGroup{}                       // Used to wait for all tests to finish
+	mu := &sync.Mutex{}                           // Used to lock shared memory in critical sections
+	sem = make(Semaphore, *maxConcurrentRequests) // Used to limit resources while having all requests queued up
 
+	// Loop through all redirects and queue them up
 	for _, redirect := range redirects {
-		wg.Add(1)
-		P(1)
+		wg.Add(1) // Add 1 resource to waitgroup
+		P(1)      // Take 1 resource from semaphore
 
+		// This anonymous function executes in a separate go routine and can run concurrently
 		go func(redirect Redirect) {
-			defer V(1)
-			defer wg.Done()
+			defer V(1)      // If function exits (error or otherwise), put 1 resource back into semaphore
+			defer wg.Done() // If function exits (error or otherwise), subtract 1 resource from waitgroup
+
+			// Create an HTTP client and override CheckRedirect to return the last response error so we can check the redirect type
 			client := &http.Client{
 				CheckRedirect: func(req *http.Request, via []*http.Request) error {
 					return http.ErrUseLastResponse
@@ -46,33 +53,35 @@ func test(redirects []Redirect) error {
 
 			// Check the status code
 			if resp.StatusCode != redirect.statusCode {
-				// Modifying output is critical section
+				// Modifying summaryOutput is critical section
 				mu.Lock()
 				summaryOutput += fmt.Sprintf("redirect for source URL '%s': expected status code'%d': got '%d\n", redirect.sourceURL, redirect.statusCode, resp.StatusCode)
 				mu.Unlock()
 				return
 			}
 
-			// Check that the redirect went to the correct location
+			// Parse response location URL from header into URL object
 			destURL, err := resp.Location()
 			if err != nil {
 				log.Printf("failed to parse response location to URL: %v", err)
 			}
 
+			// Check that the redirect went to the correct location
 			if destURL.String() != redirect.destinationURL {
-				// Modifying output is critical section
+				// Modifying summyarOutput is critical section
 				mu.Lock()
 				summaryOutput += fmt.Sprintf("redirect for source URL '%s': expected '%s': got '%s\n", redirect.sourceURL, redirect.destinationURL, destURL.String())
 				mu.Unlock()
 				return
 			}
-
 		}(redirect)
 	}
 
+	// Wait for all tests to complete
 	wg.Wait()
 	fmt.Printf("\ndone tests.\n---------------------------------------------\n")
 
+	// Display summaryOutput if any tests failed
 	if len(summaryOutput) > 0 {
 		fmt.Printf("Summary:\n\n%s", summaryOutput)
 	} else {