Added comments and LICENSE

LICENSE

@@ -0,0 +1,19 @@
+Copyright (c) 2020 Eldwan Brianne <12190353+ebrianne@users.noreply.github.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

internal/adguard/client.go

@@ -89,7 +89,7 @@ func (c *Client) getStatistics() *Stats {
 
   req, err := http.NewRequest("GET", statsURL, nil)
   if err != nil {
-    log.Fatal("An error has occured when creating HTTP statistics request ", err)
+    log.Fatal("An error has occurred when creating HTTP statistics request ", err)
   }
 
   if c.isUsingPassword() {
@@ -98,7 +98,7 @@ func (c *Client) getStatistics() *Stats {
 
   resp, err := c.httpClient.Do(req)
   if err != nil {
-    log.Printf("An error has occured during login to Adguard: %v", err)
+    log.Printf("An error has occurred during login to Adguard: %v", err)
   }
 
   body, err := ioutil.ReadAll(resp.Body)

internal/adguard/model.go

@@ -2,10 +2,7 @@ package adguard
 
 import "fmt"
 
-const (
+// Stats struct is the Adguard statistics JSON API corresponding model.
-  enabledStatus = "enabled"
-)
-
 type Stats struct {
   AvgProcessingTime     float64            `json:"avg_processing_time"`
   DnsQueries            int                `json:"num_dns_queries"`

internal/metrics/metrics.go

@@ -7,6 +7,7 @@ import (
 )
 
 var (
+  // AvgProcessingTime - Average processing time for a DNS query
   AvgProcessingTime = prometheus.NewGaugeVec(
     prometheus.GaugeOpts{
       Name:      "avg_processing_time",
@@ -16,6 +17,7 @@ var (
     []string{"hostname"},
   )
 
+  // DnsQueries - Number of DNS queries
   DnsQueries = prometheus.NewGaugeVec(
     prometheus.GaugeOpts{
       Name:      "num_dns_queries",
@@ -25,6 +27,7 @@ var (
     []string{"hostname"},
   )
 
+  // BlockedFiltering - Number of DNS queries blocked
   BlockedFiltering = prometheus.NewGaugeVec(
     prometheus.GaugeOpts{
       Name:      "num_blocked_filtering",
@@ -34,6 +37,7 @@ var (
     []string{"hostname"},
   )
 
+  // ParentalFiltering - Number of DNS queries replaced by parental control
   ParentalFiltering = prometheus.NewGaugeVec(
     prometheus.GaugeOpts{
       Name:      "num_replaced_parental",
@@ -43,6 +47,7 @@ var (
     []string{"hostname"},
   )
 
+  // SafeBrowsingFiltering - Number of DNS queries replaced by safe browsing
   SafeBrowsingFiltering = prometheus.NewGaugeVec(
     prometheus.GaugeOpts{
       Name:      "num_replaced_safebrowsing",
@@ -52,6 +57,7 @@ var (
     []string{"hostname"},
   )
 
+  // SafeSearchFiltering - Number of DNS queries replaced by safe search
   SafeSearchFiltering = prometheus.NewGaugeVec(
     prometheus.GaugeOpts{
       Name:      "num_replaced_safesearch",
@@ -61,6 +67,7 @@ var (
     []string{"hostname"},
   )
 
+  // TopQueries - The number of top queries
   TopQueries = prometheus.NewGaugeVec(
     prometheus.GaugeOpts{
       Name:      "top_queried_domains",
@@ -70,6 +77,7 @@ var (
     []string{"hostname", "domain"},
   )
 
+  // TopBlocked - The number of top domains blocked
   TopBlocked = prometheus.NewGaugeVec(
     prometheus.GaugeOpts{
       Name:      "top_blocked_domains",
@@ -79,6 +87,7 @@ var (
     []string{"hostname", "domain"},
   )
 
+  // TopClients - The number of top clients
   TopClients = prometheus.NewGaugeVec(
     prometheus.GaugeOpts{
       Name:      "top_clients",