'Received plaintext http traffic on an https channel, closing connection

I have deployed ECK (using helm) on my k8s cluster and i am attempting to install elasticsearch following the docs. https://www.elastic.co/guide/en/cloud-on-k8s/current/k8s-deploy-elasticsearch.html

I have externally exposed service/elasticsearch-prod-es-http so that i can connect to it from outside of my k8s cluster. However as you can see when i try to connect to it either from curl or the browser i receive an error "502 Bad Gateway" error.

curl elasticsearch.dev.acme.com
<html>
<head><title>502 Bad Gateway</title></head>
<body>
<center><h1>502 Bad Gateway</h1></center>
</body>
</html>

Upon checking the pod (elasticsearch-prod-es-default-0) i can see the following message repeated.

{"type": "server", "timestamp": "2021-04-27T13:12:20,048Z", "level": "WARN", "component": "o.e.x.s.t.n.SecurityNetty4HttpServerTransport", "cluster.name": "elasticsearch-prod", "node.name": "elasticsearch-prod-es-default-0", "message": "received plaintext http traffic on an https channel, closing connection Netty4HttpChannel{localAddress=/10.0.5.81:9200, remoteAddress=/10.0.3.50:46380}", "cluster.uuid": "t0mRfv7kREGQhXW9DVM3Vw", "node.id": "nCyAItDmSqGZRa3lApsC6g" }

Can you help me understand why this is occuring and how to fix it?

I suspect it has something to do with my TLS configuration because when i disable TLS, im able to connect to it externally without issues. However in a production environment i think keeping TLS enabled is important?

FYI i am able to port-forward the service and connect to it with curl using the -k flag.

What i have tried

I have tried adding my domain to the section as described here https://www.elastic.co/guide/en/cloud-on-k8s/current/k8s-http-settings-tls-sans.html#k8s-elasticsearch-http-service-san
I have tried using openssl to generate a self signed certificate but that did not work. Trying to connect locally returns the following error message.

curl -u "elastic:$PASSWORD" "https://localhost:9200" curl: (60) SSL certificate problem: unable to get local issuer certificate More details here: https://curl.haxx.se/docs/sslcerts.html curl failed to verify the legitimacy of the server and therefore could not establish a secure connection to it. To learn more about this situation and how to fix it, please visit the web page mentioned above.

I have tried generating a certificate using the tool https://www.elastic.co/guide/en/elasticsearch/reference/7.9/configuring-tls.html#tls-transport

bin/elasticsearch-certutil ca bin/elasticsearch-certutil cert --ca elastic-stack-ca.12 --pem

Then using the .crt and .key generated i created a kubectl secret elastic-tls-cert. But again curling localhost without -k gave the following error:

curl --cacert cacert.pem -u "elastic:$PASSWORD" -XGET "https://localhost:9200" curl: (60) SSL certificate problem: unable to get local issuer certificate More details here: https://curl.haxx.se/docs/sslcerts.html curl failed to verify the legitimacy of the server and therefore could not establish a secure connection to it. To learn more about this situation and how to fix it, please visit the web page mentioned above.

elasticsearch.yml

# This sample sets up an Elasticsearch cluster with 3 nodes.
apiVersion: elasticsearch.k8s.elastic.co/v1
kind: Elasticsearch
metadata:
  name: elasticsearch-prod
  namespace: elastic-system
spec:
  version: 7.12.0
  nodeSets:
  - name: default
    config:
      # most Elasticsearch configuration parameters are possible to set, e.g: node.attr.attr_name: attr_value
      node.roles: ["master", "data", "ingest", "ml"]
      # this allows ES to run on nodes even if their vm.max_map_count has not been increased, at a performance cost
      node.store.allow_mmap: false
      xpack.security.enabled: true
    podTemplate:
      metadata:
        labels:
          # additional labels for pods
          foo: bar
      spec:
        nodeSelector: 
          acme/node-type: ops

        # this changes the kernel setting on the node to allow ES to use mmap
        # if you uncomment this init container you will likely also want to remove the
        # "node.store.allow_mmap: false" setting above
        # initContainers:
        # - name: sysctl
        #   securityContext:
        #     privileged: true
        #   command: ['sh', '-c', 'sysctl -w vm.max_map_count=262144']
        ###
        # uncomment the line below if you are using a service mesh such as linkerd2 that uses service account tokens for pod identification.
        # automountServiceAccountToken: true
        containers:
        - name: elasticsearch
          # specify resource limits and requests
          resources:
            limits:
              memory: 4Gi
              cpu: 1
          env:
          - name: ES_JAVA_OPTS
            value: "-Xms2g -Xmx2g"
    count: 3
  #   # request 2Gi of persistent data storage for pods in this topology element
    volumeClaimTemplates:
    - metadata:
        name: elasticsearch-data
      spec:
        accessModes:
        - ReadWriteOnce
        resources:
          requests:
            storage: 250Gi
        storageClassName: elasticsearch
  # # inject secure settings into Elasticsearch nodes from k8s secrets references
  # secureSettings:
  # - secretName: ref-to-secret
  # - secretName: another-ref-to-secret
  #   # expose only a subset of the secret keys (optional)
  #   entries:
  #   - key: value1
  #     path: newkey # project a key to a specific path (optional)
  http:
    service:
      spec:
        # expose this cluster Service with a LoadBalancer
        type: NodePort
    # tls:
      # selfSignedCertificate:
        # add a list of SANs into the self-signed HTTP certificate
        subjectAltNames:
        # - ip: 192.168.1.2
        # - ip: 192.168.1.3
        # - dns: elasticsearch.dev.acme.com
        # - dns: localhost
      # certificate:
      #   # provide your own certificate
      #   secretName: elastic-tls-cert

kubectl version

Client Version: version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.4", GitCommit:"e87da0bd6e03ec3fea7933c4b5263d151aafd07c", GitTreeState:"clean", BuildDate:"2021-02-18T16:12:00Z", GoVersion:"go1.15.8", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"19+", GitVersion:"v1.19.6-eks-49a6c0", GitCommit:"49a6c0bf091506e7bafcdb1b142351b69363355a", GitTreeState:"clean", BuildDate:"2020-12-23T22:10:21Z", GoVersion:"go1.15.5", Compiler:"gc", Platform:"linux/amd64"}

helm list

    NAME                NAMESPACE       REVISION    UPDATED                                 STATUS      CHART               APP VERSION
elastic-operator    elastic-system  1           2021-04-26 11:18:02.286692269 +0100 BST deployed    eck-operator-1.5.0  1.5.0

resources

pod/elastic-operator-0                1/1     Running   0          4h58m   10.0.5.142   ip-10-0-5-71.us-east-2.compute.internal    <none>           <none>
pod/elasticsearch-prod-es-default-0   1/1     Running   0          9m5s    10.0.5.81    ip-10-0-5-71.us-east-2.compute.internal    <none>           <none>
pod/elasticsearch-prod-es-default-1   1/1     Running   0          9m5s    10.0.1.128   ip-10-0-1-207.us-east-2.compute.internal   <none>           <none>
pod/elasticsearch-prod-es-default-2   1/1     Running   0          9m5s    10.0.5.60    ip-10-0-5-71.us-east-2.compute.internal    <none>           <none>

NAME                                      TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE    SELECTOR
service/elastic-operator-webhook          ClusterIP   172.20.218.208   <none>        443/TCP          26h    app.kubernetes.io/instance=elastic-operator,app.kubernetes.io/name=elastic-operator
service/elasticsearch-prod-es-default     ClusterIP   None             <none>        9200/TCP         9m5s   common.k8s.elastic.co/type=elasticsearch,elasticsearch.k8s.elastic.co/cluster-name=elasticsearch-prod,elasticsearch.k8s.elastic.co/statefulset-name=elasticsearch-prod-es-default
service/elasticsearch-prod-es-http        NodePort    172.20.229.173   <none>        9200:30604/TCP   9m6s   common.k8s.elastic.co/type=elasticsearch,elasticsearch.k8s.elastic.co/cluster-name=elasticsearch-prod
service/elasticsearch-prod-es-transport   ClusterIP   None             <none>        9300/TCP         9m6s   common.k8s.elastic.co/type=elasticsearch,elasticsearch.k8s.elastic.co/cluster-name=elasticsearch-prod

aws alb ingress controller

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: elastic-ingress
  namespace: elastic-system
  annotations:
    kubernetes.io/ingress.class: alb
    alb.ingress.kubernetes.io/group.name: "<redacted>"
    alb.ingress.kubernetes.io/scheme: internet-facing
    alb.ingress.kubernetes.io/listen-ports: '[{"HTTP":80,"HTTPS": 443}]'
    alb.ingress.kubernetes.io/certificate-arn: <redacted>
    alb.ingress.kubernetes.io/tags: Environment=prod,Team=dev
    alb.ingress.kubernetes.io/healthcheck-path: /health
    alb.ingress.kubernetes.io/healthcheck-interval-seconds: '300'
    alb.ingress.kubernetes.io/load-balancer-attributes: access_logs.s3.enabled=true,access_logs.s3.bucket=acme-aws-ingress-logs,access_logs.s3.prefix=dev-ingress
spec:
  rules:
    - host: elasticsearch.dev.acme.com
      http:
        paths:
          - path: /*
            pathType: Prefix
            backend:
              service:
                name: elasticsearch-prod-es-http
                port:
                  number: 9200
    # - host: kibana.dev.acme.com
    #   http:
    #     paths:
    #       - path: /*
    #         pathType: Prefix
    #         backend:
    #           service:
    #             name: kibana-prod-kb-http
    #             port:
    #               number: 5601

kubernetes elastic-stack

Solution 1:^[1]

If anyone comes across this problem in the future, make sure your ingress is properly configured. The error message suggests that its a misconfiguration with the ingress.

received plaintext http traffic on an https channel, closing connection

In my case i am using aws-load-balancer-controller. I had to attach a annotation to my ingress that forces the connection to be HTTPS rather than HTTP.

alb.ingress.kubernetes.io/backend-protocol: "HTTPS"

For my case this problem was fixed by setting the above annotation to my ingress file and it has nothing to do with setting up a custom/private TLS certificate.

Solution 2:^[2]

solution for me: http => https

Solution 3:^[3]

You have to disable http ssl, for this you have to modify the config/elasticsearch.yml file and change the associated variable to false:

xpack.security.http.ssl:
   enabled: false
   keystore.path: certs/http.p12

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1	Kay
Solution 2	Royer Adames
Solution 3	Jorge Mora

'Received plaintext http traffic on an https channel, closing connection

Solution 1:[1]

Solution 2:[2]

Solution 3:[3]

Sources

Related Questions

Solution 1:^[1]

Solution 2:^[2]

Solution 3:^[3]