How to access the Azure App Service Log from a code with go lang

Question

How to access the Azure App Service Log from a code with go lang

Jyoti Mallick 40

Hi Community,

I want to access the Azure app service's log from an internal code using Golang. All I have is an access key. Please put some insights here.

I have my app service running on Azure,https://<prodserver>.scm.azurewebsites.net/ and the log files are maintained under /wwwroot/logs/.

If I want to access it from the browser, I am able to access through https://<prodserver>.scm.azurewebsites.net/wwwroot/logs/

But I want to access it from the code with GoLang. I have an access key to access the request. Can someone please help me to achieve this? When I am using Access Key in the code, I am getting https status code 403.

Can some one help me how to access these log files without any hindrance??

Shree Hima Bindu Maganti 4,925 Microsoft External Staff Moderator

Hi @Jyoti Mallick
Welcome to the Microsoft Q&A Platform!
To access Azure App Service logs using Golang and an access key,

Use the deployment credentials or publishing profile access key.
Send the key in a Basic authentication header.

Use the Kudu (SCM) endpoint to access the logs.
https://<prodserver>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/

  https://<prodserver>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/package main
  import (
  	"encoding/base64"
  	"fmt"
  	"io/ioutil"
  	"log"
  	"net/http"
  )
  func main() {
  	// Replace with your server and access key
  	server := "<prodserver>"
  	accessKey := "<your-access-key>"
  	url := fmt.Sprintf("https://%s.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/", server)
  	// Prepare Basic authentication header
  	auth := base64.StdEncoding.EncodeToString([]byte(":" + accessKey))
  	// Create HTTP GET request
  	req, err := http.NewRequest("GET", url, nil)
  	if err != nil {
  		log.Fatalf("Error creating request: %v", err)
  	}
  	req.Header.Set("Authorization", "Basic "+auth)
  	// Execute the request
  	client := &http.Client{}
  	resp, err := client.Do(req)
  	if err != nil {
  		log.Fatalf("Request failed: %v", err)
  	}
  	defer resp.Body.Close()
  	// Handle response
  	if resp.StatusCode != http.StatusOK {
  		log.Fatalf("Error: %s", resp.Status)
  	}
  	body, err := ioutil.ReadAll(resp.Body)
  	if err != nil {
  		log.Fatalf("Error reading response body: %v", err)
  	}
  	// Print log files
  	fmt.Println(string(body))
  }

Ensure the access key is valid by testing manually.

  curl -u :<access-key> https://<prodserver>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/

https://github.com/projectkudu/kudu/wiki/REST-API

Ensure the access key is correct and has permissions.
Verify your IP is allowed to access the App Service.
Ensure you’re using the correct Kudu API path.

Jyoti Mallick 40 Reputation points

2025-01-09T09:06:18.4733333+00:00

@Shree Hima Bindu Maganti Thank you so much for the prompt answer. But I am getting the error with the code.

Jyoti Mallick 40

@Shree Hima Bindu Maganti thank you so much for the prompt answer, I am getting error of http status code.Error: 401 Unauthorized exit status 1

I have changed the code as follows:

package main
import (
	"encoding/base64"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
)
func main() {
	accessKey := "<accessKey>"
	url := fmt.Sprintf("https://<prod_server>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/")
	// Prepare Basic authentication header
	auth := base64.StdEncoding.EncodeToString([]byte(":" + accessKey))
	// Create HTTP GET request
	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		log.Fatalf("Error creating request: %v", err)
	}
	req.Header.Set("Authorization", "Basic "+auth)
	// Execute the request
	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		log.Fatalf("Request failed: %v", err)
	}
	defer resp.Body.Close()
	// Handle response
	if resp.StatusCode != http.StatusOK {
		log.Fatalf("Error: %s", resp.Status)
	}
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Fatalf("Error reading response body: %v", err)
	}
	// Print log files
	fmt.Println(string(body))
}

By the way, I can see the logs in the Kudu API Directory.

User's image

I am having a doubt over the access key, I am using the access key for the storage account for the same RG where the azure app service is running.

User's image

What I am missing here ?

Shree Hima Bindu Maganti 4,925 Reputation points Microsoft External Staff Moderator

2025-01-21T08:24:35.28+00:00

Hi @Jyoti Mallick Following up to see if you have chance to check my previous response and help us with requested information is helpful.
Shree Hima Bindu Maganti 4,925 Reputation points Microsoft External Staff Moderator

2025-01-23T11:59:00.6533333+00:00

Hi @Jyoti Mallick
Following up to see if you have chance to check my previous response and help us with requested information is helpful.

Accepted answer

0 additional answers

Your answer

Shree Hima Bindu Maganti 4,925 Reputation points Microsoft External Staff Moderator

2025-01-08T18:02:08.42+00:00

Hi @Jyoti Mallick
Welcome to the Microsoft Q&A Platform!
To access Azure App Service logs using Golang and an access key,

Use the deployment credentials or publishing profile access key.

Send the key in a Basic authentication header.

Use the Kudu (SCM) endpoint to access the logs.
https://<prodserver>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/
https://<prodserver>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/package main import ( "encoding/base64" "fmt" "io/ioutil" "log" "net/http" ) func main() { // Replace with your server and access key server := "<prodserver>" accessKey := "<your-access-key>" url := fmt.Sprintf("https://%s.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/", server) // Prepare Basic authentication header auth := base64.StdEncoding.EncodeToString([]byte(":" + accessKey)) // Create HTTP GET request req, err := http.NewRequest("GET", url, nil) if err != nil { log.Fatalf("Error creating request: %v", err) } req.Header.Set("Authorization", "Basic "+auth) // Execute the request client := &http.Client{} resp, err := client.Do(req) if err != nil { log.Fatalf("Request failed: %v", err) } defer resp.Body.Close() // Handle response if resp.StatusCode != http.StatusOK { log.Fatalf("Error: %s", resp.Status) } body, err := ioutil.ReadAll(resp.Body) if err != nil { log.Fatalf("Error reading response body: %v", err) } // Print log files fmt.Println(string(body)) }
Ensure the access key is valid by testing manually.
curl -u :<access-key> https://<prodserver>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/
https://github.com/projectkudu/kudu/wiki/REST-API

Ensure the access key is correct and has permissions.

Verify your IP is allowed to access the App Service.

Ensure you’re using the correct Kudu API path.
Jyoti Mallick 40 Reputation points

2025-01-09T09:06:18.4733333+00:00

@Shree Hima Bindu Maganti Thank you so much for the prompt answer. But I am getting the error with the code.
Jyoti Mallick 40 Reputation points

2025-01-09T09:11:34.1733333+00:00

@Shree Hima Bindu Maganti thank you so much for the prompt answer, I am getting error of http status code.Error: 401 Unauthorized exit status 1

I have changed the code as follows:

package main import ( "encoding/base64" "fmt" "io/ioutil" "log" "net/http" ) func main() { accessKey := "<accessKey>" url := fmt.Sprintf("https://<prod_server>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/") // Prepare Basic authentication header auth := base64.StdEncoding.EncodeToString([]byte(":" + accessKey)) // Create HTTP GET request req, err := http.NewRequest("GET", url, nil) if err != nil { log.Fatalf("Error creating request: %v", err) } req.Header.Set("Authorization", "Basic "+auth) // Execute the request client := &http.Client{} resp, err := client.Do(req) if err != nil { log.Fatalf("Request failed: %v", err) } defer resp.Body.Close() // Handle response if resp.StatusCode != http.StatusOK { log.Fatalf("Error: %s", resp.Status) } body, err := ioutil.ReadAll(resp.Body) if err != nil { log.Fatalf("Error reading response body: %v", err) } // Print log files fmt.Println(string(body)) }

By the way, I can see the logs in the Kudu API Directory.

I am having a doubt over the access key, I am using the access key for the storage account for the same RG where the azure app service is running.

What I am missing here ?
Shree Hima Bindu Maganti 4,925 Reputation points Microsoft External Staff Moderator

2025-01-21T08:24:35.28+00:00

Hi @Jyoti Mallick Following up to see if you have chance to check my previous response and help us with requested information is helpful.
Shree Hima Bindu Maganti 4,925 Reputation points Microsoft External Staff Moderator

2025-01-23T11:59:00.6533333+00:00

Hi @Jyoti Mallick
Following up to see if you have chance to check my previous response and help us with requested information is helpful.

Answer 1

Hi @Jyoti Mallick
Sorry for the delay Response.
Based on your updated Go code and error details, the 401 Unauthorized error indicates that the access key being used for authentication is invalid or is not being applied correctly.

Download the Publishing Profile from your App Service in the Azure Portal.
Extract the username and password from the .PublishSettings file.
Encode the credentials as username:password in Base64 auth := base64.StdEncoding.EncodeToString([]byte("<username>:<password>"))
Use the Authorization header with Basic authentication req.Header.Set("Authorization", "Basic "+auth)
Use the correct Kudu API URL https://<app-service-name>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/

Updated Code .

  package main
  import (
  	"encoding/base64"
  	"fmt"
  	"io/ioutil"
  	"log"
  	"net/http"
  )
  func main() {
  	username := "<username-from-publishing-profile>"
  	password := "<password-from-publishing-profile>"
  	url := "https://<app-service-name>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/"
  	// Prepare Basic authentication header
  	auth := base64.StdEncoding.EncodeToString([]byte(username + ":" + password))
  	// Create HTTP GET request
  	req, err := http.NewRequest("GET", url, nil)
  	if err != nil {
  		log.Fatalf("Error creating request: %v", err)
  	}
  	req.Header.Set("Authorization", "Basic "+auth)
  	// Execute the request
  	client := &http.Client{}
  	resp, err := client.Do(req)
  	if err != nil {
  		log.Fatalf("Request failed: %v", err)
  	}
  	defer resp.Body.Close()
  	// Handle response
  	if resp.StatusCode != http.StatusOK {
  		log.Fatalf("Error: %s", resp.Status)
  	}
  	body, err := ioutil.ReadAll(resp.Body)
  	if err != nil {
  		log.Fatalf("Error reading response body: %v", err)
  	}
  	// Print log files
  	fmt.Println(string(body))
  }

Use curl to validate curl -u <username>:<password> https://<app-service-name>.scm.azurewebsites.net/api/vfs/site/wwwroot/logs/
If the answer is helpful, please click Accept Answer and kindly upvote it so that other people who faces similar issue may get benefitted from it.

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How to access the Azure App Service Log from a code with go lang

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