telegraf: Telegraf Graylog Doesn't Pull Metrics

@hackdefendr I am using an api-token to access. I have used this method since Graylog 2.3 series to access API to use it to pull performance metrics via Zabbix and then alerts in Grafana. I have replicated same method here for TICK stack.

From Joschi (Graylog Guy) - Github repo

Accessing API via token (see line 35) https://gist.github.com/joschi/21bc88207881581099570dd85588f7df[https://gist.github.com/joschi/21bc88207881581099570dd85588f7df

Accessing API via session token https://gist.github.com/joschi/72fb7e75b171c10d3717

You will see that accessing via sesion token has an expiry and so is not suitable for use with telegraf plugin. In your initial post, you are showing a username and password possibly in your telegraf.conf. I suggest replacing with an API key with appropriate permissions. I generally use an admin level key.

From your initial post.

## Username and password
  username = "admin"
  password = "********"

In the telegraf graylog input plugin at https://github.com/influxdata/telegraf/blob/master/plugins/inputs/graylog/graylog.go

We can see the following

Function Gather server makes the request and within in the function sendRequest(serverURL) makes the request.

//	error: Any error that may have occurred
func (h *GrayLog) gatherServer(
	acc telegraf.Accumulator,
	serverURL string,
) error {
	resp, _, err := h.sendRequest(serverURL)
	if err != nil {
		return err
	}
	requestURL, err := url.Parse(serverURL)
	if err != nil {
		return fmt.Errorf("unable to parse address '%s': %s", serverURL, err)
	}

	host, port, _ := net.SplitHostPort(requestURL.Host)
	var dat ResponseMetrics
	if err := json.Unmarshal([]byte(resp), &dat); err != nil {
		return err
	}
	for _, mItem := range dat.Metrics {
		fields := make(map[string]interface{})
		tags := map[string]string{
			"server": host,
			"port":   port,
			"name":   mItem.Name,
			"type":   mItem.Type,
		}
		h.flatten(mItem.Fields, fields, "")
		acc.AddFields(mItem.FullName, fields, tags)
	}
	return nil
}

An in the sendRequest method, we see

func (h *GrayLog) sendRequest(serverURL string) (string, float64, error) {
	headers := map[string]string{
		"Content-Type": "application/json",
		"Accept":       "application/json",
	}
	method := "GET"
	content := bytes.NewBufferString("")
	headers["Authorization"] = "Basic " + base64.URLEncoding.EncodeToString([]byte(h.Username+":"+h.Password))
	// Prepare URL
	requestURL, err := url.Parse(serverURL)

This means that if we set the username to the value of an api token and password to “token” , it will match the token example from before so that the authorisation header would be.

For example

api key = 8oe6l5b0db378b0qfsufa1j9jr4bnlvng1m6o998rag8fcmusj1
username =token

Will result in the following header

Authorisation: Basic 8oe6l5b0db378b0qfsufa1j9jr4bnlvng1m6o998rag8fcmusj1:token

Therefore looking at the examples provided it is clear that only the permanent api token method is supported. @powersj I think the documentation needs to be updated to reflect this issue or the code could be changed to support session method as well. However, the plugin works and does not need to be depreciated.

Hope this helps. Cyberkryption

I really appreciate that you took the time to look! I’ll leave this bug open to track deprecating the plugin.

I spent the previous evening looking over the code for this plugin and I don’t even know Go, but I was willing to try. In the end, I have nothing to show. I have no idea how to fix this plugin and if you don’t have the time then deprecation is the right path.