From 03e0b11e4e45919cc4194b3ae600a68b5e43b559 Mon Sep 17 00:00:00 2001
From: Adhityaa Chandrasekar <adtac@adtac.in>
Date: Thu, 16 Aug 2018 23:45:59 +0530
Subject: [PATCH] api: add version checking

---
 api/constants.go |  4 +++
 api/main.go      |  1 +
 api/version.go   | 78 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+)
 create mode 100644 api/constants.go
 create mode 100644 api/version.go

diff --git a/api/constants.go b/api/constants.go
new file mode 100644
index 0000000..79052bf
--- /dev/null
+++ b/api/constants.go
@@ -0,0 +1,4 @@
+package main
+
+var edition = "ce"
+var version = "v1.0.0"
diff --git a/api/main.go b/api/main.go
index 59c814a..7d309d2 100644
--- a/api/main.go
+++ b/api/main.go
@@ -10,6 +10,7 @@ func main() {
 	exitIfError(oauthConfigure())
 	exitIfError(markdownRendererCreate())
 	exitIfError(sigintCleanupSetup())
+	exitIfError(versionCheckStart())
 
 	exitIfError(routesServe())
 }
diff --git a/api/version.go b/api/version.go
new file mode 100644
index 0000000..216c63b
--- /dev/null
+++ b/api/version.go
@@ -0,0 +1,78 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"os"
+	"time"
+)
+
+func versionCheckStart() error {
+	go func() {
+		printedError := false
+		errorCount := 0
+
+		for {
+			time.Sleep(5 * time.Minute)
+
+			data := url.Values{
+				"origin":  {os.Getenv("ORIGIN")},
+				"edition": {edition},
+				"version": {version},
+			}
+
+			resp, err := http.Post("https://version.commento.io/api/check", "application/x-www-form-urlencoded", bytes.NewBufferString(data.Encode()))
+			if err != nil {
+				errorCount++
+				// print the error only once; we don't want to spam the logs with this
+				// every five minutes
+				if !printedError && errorCount > 5 {
+					logger.Errorf("error checking version: %v", err)
+					printedError = true
+				}
+				continue
+			}
+			defer resp.Body.Close()
+
+			body, err := ioutil.ReadAll(resp.Body)
+			if err != nil {
+				errorCount++
+				if !printedError && errorCount > 5 {
+					logger.Errorf("error reading body: %s", err)
+					printedError = true
+				}
+				continue
+			}
+
+			type response struct {
+				Success   bool   `json:"success"`
+				Message   string `json:"message"`
+				Latest    string `json:"latest"`
+				NewUpdate bool   `json:"newUpdate"`
+			}
+
+			r := response{}
+			json.Unmarshal(body, &r)
+			if r.Success == false {
+				errorCount++
+				if !printedError && errorCount > 5 {
+					logger.Errorf("error checking version: %s", r.Message)
+					printedError = true
+				}
+				continue
+			}
+
+			if r.NewUpdate {
+				logger.Infof("New update available! Latest version: %s", r.Latest)
+			}
+
+			errorCount = 0
+			printedError = false
+		}
+	}()
+
+	return nil
+}