firehol/netdata

// SPDX-License-Identifier: GPL-3.0-or-later

package k8s_state

import (
    "errors"
    "fmt"
    "io"
    "net/http"
    "time"

    "github.com/netdata/netdata/go/plugins/plugin/go.d/pkg/web"

    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

func (ks *KubeState) getKubeClusterID() string {
    ns, err := ks.client.CoreV1().Namespaces().Get(ks.ctx, "kube-system", metav1.GetOptions{})
    if err != nil {
        ks.Warningf("error on getting 'kube-system' namespace UID: %v", err)
        return ""
    }
    return string(ns.UID)
}

func (ks *KubeState) getKubeClusterName() string {
    client := &http.Client{Timeout: time.Second}
    n, err := getGKEKubeClusterName(client)
    if err != nil {
        ks.Debugf("error on getting GKE cluster name: %v", err)
    }
    return n
}

func getGKEKubeClusterName(client *http.Client) (string, error) {
    id, err := doMetaGKEHTTPReq(client, "http://metadata/computeMetadata/v1/project/project-id")
    if err != nil {
        return "", err
    }
    loc, err := doMetaGKEHTTPReq(client, "http://metadata/computeMetadata/v1/instance/attributes/cluster-location")
    if err != nil {
        return "", err
    }
    name, err := doMetaGKEHTTPReq(client, "http://metadata/computeMetadata/v1/instance/attributes/cluster-name")
    if err != nil {
        return "", err
    }

    return fmt.Sprintf("gke_%s_%s_%s", id, loc, name), nil
}

func doMetaGKEHTTPReq(client *http.Client, url string) (string, error) {
    req, err := http.NewRequest(http.MethodGet, url, nil)
    if err != nil {
        return "", err
    }

    req.Header.Add("Metadata-Flavor", "Google")

    var resp string

    if err := web.DoHTTP(client).Request(req, func(body io.Reader) error {
        bs, rerr := io.ReadAll(body)
        if rerr != nil {
            return rerr
        }

        if resp = string(bs); len(resp) == 0 {
            return errors.New("empty response")
        }

        return nil
    }); err != nil {
        return "", err
    }

    return resp, nil
}