From 4052552ab13b658cb8a31fb88d0703fccfb8db93 Mon Sep 17 00:00:00 2001
From: Abhinav Pandey <abhinavmpandey08@gmail.com>
Date: Mon, 20 Jun 2022 17:30:53 -0400
Subject: [PATCH] Modify write-file to read multiple HEGEL_URLS

Signed-off-by: Abhinav Pandey <abhinavmpandey08@gmail.com>
---
 actions/writefile/v1/main.go | 58 +++++++++++++++++++++++-------------
 1 file changed, 37 insertions(+), 21 deletions(-)

diff --git a/actions/writefile/v1/main.go b/actions/writefile/v1/main.go
index 23ca768..cfd9974 100644
--- a/actions/writefile/v1/main.go
+++ b/actions/writefile/v1/main.go
@@ -48,7 +48,7 @@ func main() {
 
 	contents := os.Getenv("CONTENTS")
 	bootconfig := os.Getenv("BOOTCONFIG_CONTENTS")
-	hegelUrl := os.Getenv("HEGEL_URL")
+	hegelUrls := os.Getenv("HEGEL_URLS")
 	uid := os.Getenv("UID")
 	gid := os.Getenv("GID")
 	mode := os.Getenv("MODE")
@@ -87,15 +87,15 @@ func main() {
 		log.Fatalf("Could not parse mode: %v", err)
 	}
 
-	// Only set one of contents, bootconfig or hegelUrl
+	// Only set one of contents, bootconfig or hegelUrls
 	validationCount := 0
-	for _, envVar := range []string{contents, bootconfig, hegelUrl} {
+	for _, envVar := range []string{contents, bootconfig, hegelUrls} {
 		if envVar != "" {
 			validationCount++
 		}
 	}
 	if validationCount != 1 {
-		log.Fatal("Only one environment vars of CONTENTS, BOOTCONFIG_CONTENTS, HEGEL_URL can be set")
+		log.Fatal("Only one environment vars of CONTENTS, BOOTCONFIG_CONTENTS, HEGEL_URLS can be set")
 	}
 
 	fileMode := os.FileMode(modePrime)
@@ -138,26 +138,42 @@ func main() {
 		log.Fatalf("Failed to ensure directory exists: %v", err)
 	}
 
-	// If hegelUrl is set, get the user-data from hegel and set it to contents
-	if hegelUrl != "" {
-		userDataServiceUrl, err := url.Parse(hegelUrl)
-		if err != nil {
-			log.Fatalf("Error parsing hegel url: %v", err)
-		}
-		userDataServiceUrl.Path = path.Join(userDataServiceUrl.Path, hegelUserDataVersion, "user-data")
-		resp, err := http.Get(userDataServiceUrl.String())
-		if err != nil {
-			log.Fatalf("Error with HTTP GET call: %v", err)
-		}
-		defer resp.Body.Close()
+	if hegelUrls != "" {
+		success := false
+		// go through all urls in hegelUrls, and attempt to retrieve userdata from them
+		// upon a successful userdata retrieval, this loop will exit and populate the userdata contents in contents
+		for _, hegelUrl := range strings.Split(hegelUrls, ",") {
+			userDataServiceUrl, err := url.ParseRequestURI(hegelUrl)
+			if err != nil {
+				log.Warnf("Error parsing hegel url: %v", err)
+				continue
+			}
+			userDataServiceUrl.Path = path.Join(userDataServiceUrl.Path, hegelUserDataVersion, "user-data")
+			client := http.Client{
+				Timeout: time.Second * 10,
+			}
+			resp, err := client.Get(userDataServiceUrl.String())
+			if err != nil {
+				log.Warnf("Error with HTTP GET call: %v", err)
+				continue
+			}
+			defer resp.Body.Close()
 
-		respBody, err := ioutil.ReadAll(resp.Body)
-		if err != nil {
-			log.Fatalf("Error reading HTTP GET response body: %v", err)
+			respBody, err := ioutil.ReadAll(resp.Body)
+			if err != nil {
+				log.Warnf("Error reading HTTP GET response body: %v", err)
+				continue
+			}
+
+			// Set contents to be the user-data
+			contents = string(respBody)
+			success = true
+			break
 		}
 
-		// Set contents to be the user-data
-		contents = string(respBody)
+		if !success {
+			log.Fatalf("Failed to read user-data, exhausted all the urls defined in HEGEL_URLS: {%v}", hegelUrls)
+		}
 	}
 
 	// If bootconfig is set, contents will be empty and will serve as output initrd file provided
-- 
2.30.1 (Apple Git-130)