Question

我正在根据以下网站构建kubeadm HA https://kubernetes.io/docs/setup/independent/

我使用的环境是AWS上的Ubuntu服务器16.04。

我在构建环境时遇到了问题。

执行kubeadm init --config=config.yaml时发生以下错误。

# kubeadm init --config=config.yaml
[init] Using Kubernetes version: v1.10.3
[init] Using Authorization modes: [Node RBAC]
[preflight] Running pre-flight checks.
        [WARNING SystemVerification]: docker version is greater than the most recently validated version. Docker version: 18.03.1-ce. Max validated version: 17.03
        [WARNING FileExisting-crictl]: crictl not found in system path
Suggestion: go get github.com/kubernetes-incubator/cri-tools/cmd/crictl
[preflight] Some fatal errors occurred:
        [ERROR FileAvailable--etc-kubernetes-manifests-etcd.yaml]: /etc/kubernetes/manifests/etcd.yaml already exists
        [ERROR ExternalEtcdVersion]: couldn't parse external etcd version "": Version string empty
        [ERROR ExternalEtcdVersion]: couldn't parse external etcd version "": Version string empty
        [ERROR ExternalEtcdVersion]: couldn't parse external etcd version "": Version string empty
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`

这是config.yaml
（IP地址值为哑。）

apiVersion: kubeadm.k8s.io/v1alpha1
kind: MasterConfiguration
api:
  advertiseAddress: 192.168.0.10
etcd:
  endpoints:
  - https://192.168.0.10:2379
  - https://192.168.0.11:2379
  - https://192.168.0.12:2379
  caFile: /etc/kubernetes/pki/etcd/ca.pem
  certFile: /etc/kubernetes/pki/etcd/client.pem
  keyFile: /etc/kubernetes/pki/etcd/client-key.pem
networking:
  podSubnet: 10.244.0.0/16
apiServerCertSANs:
- <load-balancer-ip>
apiServerExtraArgs:
  apiserver-count: "3"

这是kubeadm中的错误吗？请让我知道如何解决错误。

Answer 1

您遇到的问题与 v1.10.3 kubeadm之前版本中的连接错误相关。这就是为什么你无法确切地看到正在发生的事情，并且可能会想到配置文件中的一些错误。

以下是与您的问题相关的issue。

在版本 1.10.3 中，introduced中的修正为PR #60585，因此现在您应该看到连接错误，并可以弄清楚如何修复它们。

在任何情况下，您的问题都是由连接到etcd群集端点的问题引起的。

https://192.168.0.10:2379/version
https://192.168.0.11:2379/version
https://192.168.0.12:2379/version

您可以尝试使用curl命令从使用配置文件中的证书运行kubeadm init的节点连接到该端点：

caFile: /etc/kubernetes/pki/etcd/ca.pem
certFile: /etc/kubernetes/pki/etcd/client.pem
keyFile: /etc/kubernetes/pki/etcd/client-key.pem

以下是一个例子：

curl --cacert /etc/kubernetes/pki/etcd/ca.pem --cert /etc/kubernetes/pki/etcd/client.pem --key /etc/kubernetes/pki/etcd/client-key.pem   -L https://192.168.0.10:2379/version
{"etcdserver":"3.3.2","etcdcluster":"3.3.0"}

如果出现连接错误，则应在群集初始化之前解决此问题。

这是与检查外部etcd服务器版本相关的代码部分。它是从master branch：

复制而来的

// Check validates external etcd version
// TODO: Use the official etcd Golang client for this instead?
func (evc ExternalEtcdVersionCheck) Check() (warnings, errors []error) {
    glog.V(1).Infoln("validating the external etcd version")

    // Return quickly if the user isn't using external etcd
    if evc.Etcd.External.Endpoints == nil {
        return nil, nil
    }

    var config *tls.Config
    var err error
    if config, err = evc.configRootCAs(config); err != nil {
        errors = append(errors, err)
        return nil, errors
    }
    if config, err = evc.configCertAndKey(config); err != nil {
        errors = append(errors, err)
        return nil, errors
    }

    client := evc.getHTTPClient(config)
    for _, endpoint := range evc.Etcd.External.Endpoints {
        if _, err := url.Parse(endpoint); err != nil {
            errors = append(errors, fmt.Errorf("failed to parse external etcd endpoint %s : %v", endpoint, err))
            continue
        }
        resp := etcdVersionResponse{}
        var err error
        versionURL := fmt.Sprintf("%s/%s", endpoint, "version")
        if tmpVersionURL, err := purell.NormalizeURLString(versionURL, purell.FlagRemoveDuplicateSlashes); err != nil {
            errors = append(errors, fmt.Errorf("failed to normalize external etcd version url %s : %v", versionURL, err))
            continue
        } else {
            versionURL = tmpVersionURL
        }

##### Here we connect to endpoint and request version info
        if err = getEtcdVersionResponse(client, versionURL, &resp); err != nil {
            errors = append(errors, err)
            continue
        }
##### Here we print that error message in case of error on the previous step
        etcdVersion, err := semver.Parse(resp.Etcdserver)
        if err != nil {
            errors = append(errors, fmt.Errorf("couldn't parse external etcd version %q: %v", resp.Etcdserver, err))
            continue
        }
        if etcdVersion.LT(minExternalEtcdVersion) {
            errors = append(errors, fmt.Errorf("this version of kubeadm only supports external etcd version >= %s. Current version: %s", kubeadmconstants.MinExternalEtcdVersion, resp.Etcdserver))
            continue
        }
    }

    return nil, errors
}

....

func getEtcdVersionResponse(client *http.Client, url string, target interface{}) error {
    loopCount := externalEtcdRequestRetries + 1
    var err error
    var stopRetry bool
    for loopCount > 0 {
        if loopCount <= externalEtcdRequestRetries {
            time.Sleep(externalEtcdRequestInterval)
        }
        stopRetry, err = func() (stopRetry bool, err error) {
            r, err := client.Get(url)
            if err != nil {
                loopCount--
                return false, err     #### <-- this line was fixed by replacing "return false, nil"
            }
            defer r.Body.Close()

            if r != nil && r.StatusCode >= 500 && r.StatusCode <= 599 {
                loopCount--
                return false, fmt.Errorf("server responded with non-successful status: %s", r.Status)
            }
            return true, json.NewDecoder(r.Body).Decode(target)

        }()
        if stopRetry {
            break
        }
    }
    return err
}

使用kubeadm创建HA群集

1 个答案: