Updated on 2024-05-09 GMT+08:00

Creating a LoadBalancer Service

Scenario

LoadBalancer Services can access workloads from the public network through a load balancer, which is more reliable than EIP-based access. The LoadBalancer access address is in the format of IP address of public network load balancer:Access port, for example, 10.117.117.117:80.

In this access mode, requests are transmitted through an ELB load balancer to a node and then forwarded to the destination pod through the Service.

Figure 1 LoadBalancer

When CCE Turbo clusters and dedicated load balancers are used, passthrough networking is supported to reduce service latency and ensure zero performance loss.

External access requests are directly forwarded from a load balancer to pods. Internal access requests can be forwarded to a pod through a Service.

Figure 2 Passthrough networking

Constraints

  • LoadBalancer Services allow workloads to be accessed from public networks through ELB. This access mode has the following restrictions:
    • Automatically created load balancers should not be used by other resources. Otherwise, these load balancers cannot be completely deleted.
    • Do not change the listener name for the load balancer in clusters of v1.15 and earlier. Otherwise, the load balancer cannot be accessed.
  • After a Service is created, if the affinity setting is switched from the cluster level to the node level, the connection tracing table will not be cleared. Do not modify the Service affinity setting after the Service is created. To modify it, create a Service again.
  • If the service affinity is set to the node level (that is, externalTrafficPolicy is set to Local), the cluster may fail to access the Service by using the ELB address. For details, see Why a Service Fail to Be Accessed from Within the Cluster.
  • In a CCE Turbo cluster that utilizes a Cloud Native 2.0 network model, node-level affinity is supported only when the Service backend is connected to a HostNetwork pod.
  • Dedicated ELB load balancers can be used only in clusters of v1.17 and later.
  • A dedicated load balancer must be of the network type (TCP/UDP) and support private networks (with a private IP address). If the Service needs to support HTTP, the dedicated load balancers must be of the network (TCP/UDP) or application load balancing (HTTP/HTTPS) type.
  • In a CCE cluster, if the cluster-level affinity is configured for a LoadBalancer Service, requests are distributed to the node ports of each node using SNAT when entering the cluster. The number of node ports cannot exceed the number of available node ports on the node. If the service affinity is at the node level (Local), there is no such constraint. In a CCE Turbo cluster, this constraint applies to shared load balancers, but not dedicated ones. Use dedicated load balancers in CCE Turbo clusters.
  • When the cluster service forwarding (proxy) mode is IPVS, the node IP cannot be configured as the external IP of the Service. Otherwise, the node is unavailable.
  • In a cluster using the IPVS proxy mode, if the ingress and Service use the same ELB load balancer, the ingress cannot be accessed from the nodes and containers in the cluster because kube-proxy mounts the LoadBalancer Service address to the ipvs-0 bridge. This bridge intercepts the traffic of the load balancer connected to the ingress. Use different load balancers for the ingress and Service.

Creating a LoadBalancer Service

  1. Log in to the CCE console and click the cluster name to access the cluster console.
  2. In the navigation pane, choose Services & Ingresses. In the upper right corner, click Create Service.
  3. Configure parameters.

    • Service Name: Specify a Service name, which can be the same as the workload name.
    • Service Type: Select LoadBalancer.
    • Namespace: Namespace to which the workload belongs.
    • Service Affinity: For details, see externalTrafficPolicy (Service Affinity).
      • Cluster level: The IP addresses and access ports of all nodes in a cluster can access the workload associated with the Service. Service access will cause performance loss due to route redirection, and the source IP address of the client cannot be obtained.
      • Node level: Only the IP address and access port of the node where the workload is located can access the workload associated with the Service. Service access will not cause performance loss due to route redirection, and the source IP address of the client can be obtained.
    • Selector: Add a label and click Confirm. The Service will use this label to select pods. You can also click Reference Workload Label to use the label of an existing workload. In the dialog box that is displayed, select a workload and click OK.
    • IPv6: This function is disabled by default. After this function is enabled, the cluster IP address of the Service changes to an IPv6 address. For details, see Creating an IPv4/IPv6 Dual-Stack Cluster in CCE. This parameter is available only in clusters of v1.15 or later with IPv6 enabled (set during cluster creation).
    • Load Balancer: Select a load balancer type and creation mode.

      A load balancer can be dedicated or shared. A dedicated load balancer supports Network (TCP/UDP/TLS), Application (HTTP/HTTPS), or Network (TCP/UDP/TLS) & Application (HTTP/HTTPS).

      You can select Use existing or Auto create to obtain a load balancer. For details about the configuration of different creation modes, see Table 1.
      Table 1 Load balancer configurations

      How to Create

      Configuration

      Use existing

      Only the load balancers in the same VPC as the cluster can be selected. If no load balancer is available, click Create Load Balancer to create one on the ELB console.

      Auto create

      • Instance Name: Enter a load balancer name.
      • Enterprise Project: This parameter is available only for enterprise users who have enabled an enterprise project. Enterprise projects facilitate project-level management and grouping of cloud resources and users.
      • AZ: available only to dedicated load balancers. You can create load balancers in multiple AZs to improve service availability. You can deploy a load balancer in multiple AZs for high availability.
      • Frontend Subnet: available only to dedicated load balancers. It is used to allocate IP addresses for load balancers to provide services externally.
      • Backend Subnet: available only to dedicated load balancers. It is used to allocate IP addresses for load balancers to access the backend service.
      • Network/Application-oriented Specifications (available only to dedicated load balancers)
        • Fixed: applies to stable traffic, billed based on specifications.
      • EIP: If you select Auto create, you can configure the billing mode and size of the public network bandwidth.
      • Resource Tag: You can add resource tags to classify resources. You can create predefined tags on the TMS console. The predefined tags are available to all resources that support tags. You can use predefined tags to improve the tag creation and resource migration efficiency.

      You can click in the Set ELB area and configure load balancer parameters in the Set ELB dialog box.

      • Algorithm: Three algorithms are available: weighted round robin, weighted least connections algorithm, or source IP hash.
        • Weighted round robin: Requests are forwarded to different servers based on their weights, which indicate server processing performance. Backend servers with higher weights receive proportionately more requests, whereas equal-weighted servers receive the same number of requests. This algorithm is often used for short connections, such as HTTP services.
        • Weighted least connections: In addition to the weight assigned to each server, the number of connections processed by each backend server is considered. Requests are forwarded to the server with the lowest connections-to-weight ratio. Building on least connections, the weighted least connections algorithm assigns a weight to each server based on their processing capability. This algorithm is often used for persistent connections, such as database connections.
        • Source IP hash: The source IP address of each request is calculated using the hash algorithm to obtain a unique hash key, and all backend servers are numbered. The generated key allocates the client to a particular server. This enables requests from different clients to be distributed in load balancing mode and ensures that requests from the same client are forwarded to the same server. This algorithm applies to TCP connections without cookies.
      • Type: This function is disabled by default. You can select Source IP address. Source IP address-based sticky session means that access requests from the same IP address are forwarded to the same backend server.

        When the distribution policy uses the source IP hash, sticky session cannot be set.

    • Health Check: Configure health check for the load balancer.
      • Global health check: applies only to ports using the same protocol. You are advised to select Custom health check.
      • Custom health check: applies to ports using different protocols. For details about the YAML configuration for custom health check, see Configuring Health Check on Multiple Service Ports.
      Table 2 Health check parameters

      Parameter

      Description

      Protocol

      When the protocol of Port is set to TCP, the TCP and HTTP are supported. When the protocol of Port is set to UDP, the UDP is supported.

      • Check Path (supported only by HTTP for health check): specifies the health check URL. The check path must start with a slash (/) and contain 1 to 80 characters.

      Port

      By default, the service port (NodePort or container port of the Service) is used for health check. You can also specify another port for health check. After the port is specified, a service port named cce-healthz will be added for the Service.

      • Node Port: If a shared load balancer is used or no ENI instance is associated, the node port is used as the health check port. If this parameter is not specified, a random port is used. The value ranges from 30000 to 32767.
      • Container Port: When a dedicated load balancer is associated with an ENI instance, the container port is used for health check. The value ranges from 1 to 65535.

      Check Period (s)

      Specifies the maximum interval between health checks. The value ranges from 1 to 50.

      Timeout (s)

      Specifies the maximum timeout duration for each health check. The value ranges from 1 to 50.

      Max. Retries

      Specifies the maximum number of health check retries. The value ranges from 1 to 10.

    • Ports
      • Protocol: protocol used by the Service.
      • Service Port: port used by the Service. The port number ranges from 1 to 65535.
      • Container Port: listener port of the workload. For example, Nginx uses port 80 by default.
      • Frontend Protocol: the frontend protocol of the load balancer listener for establishing a traffic distribution connection with the client. When a dedicated load balancer is selected, HTTP/HTTPS can be configured only when Application (HTTP/HTTPS) is selected.
      • Health Check: If Health Check is set to Custom health check, you can configure health check for ports using different protocols. For details, see Table 2.

      When a LoadBalancer Service is created, a random node port number (NodePort) is automatically generated.

    • Listener
      • SSL Authentication: Select this option if HTTPS/TLS is enabled on the listener port.
        • One-way authentication: Only the backend server is authenticated. If you also need to authenticate the identity of the client, select mutual authentication.
        • Mutual authentication: If you want the clients and the load balancer to authenticate each other, select this option. Only authenticated clients will be allowed to access the load balancer.
      • CA Certificate: If SSL Authentication is set to Mutual authentication, add a CA certificate to authenticate the client. A CA certificate is issued by a certificate authority (CA) and used to verify the certificate issuer. If HTTPS mutual authentication is required, HTTPS connections can be established only when the client provides a certificate issued by a specific CA.
      • Server Certificate: If HTTPS/TLS is enabled on the listener port, you must select a server certificate. If no certificate is available, create one on the ELB console. For details, see Adding a Certificate.
      • SNI: If HTTPS/TLS is enabled on the listener port, you must determine whether to add an SNI certificate. Before adding an SNI certificate, ensure the certificate contains a domain name. If no certificate is available, create one on the ELB console. For details, see Adding a Certificate.

        If an SNI certificate cannot be found based on the domain name requested by the client, the server certificate will be returned by default.

      • Security Policy: If HTTPS/TLS is enabled on the listener port, you can select a security policy.
      • Backend Protocol: If HTTPS is enabled on the listener port, HTTP or HTTPS can be used to access the backend server. The default value is HTTP. If TLS is enabled on the listener port, TCP or TLS can be used to access the backend server. The default value is TCP.
      • Access Control
        • Allow all IP addresses: No access control is configured.
        • Trustlist: Only the selected IP address group can access the load balancer.
        • Blocklist: The selected IP address group cannot access the load balancer.
      • Advanced Options

        Configuration

        Description

        Restrictions

        Transfer Listener Port Number

        If this function is enabled, the listening port on the load balancer can be transferred to backend servers through the HTTP header of the packet.

        This parameter is available only after HTTP/HTTPS is enabled on the listener port of a dedicated load balancer.

        Transfer Port Number in the Request

        If this function is enabled, the source port of the client can be transferred to backend servers through the HTTP header of the packet.

        This parameter is available only after HTTP/HTTPS is enabled on the listener port of a dedicated load balancer.

        Rewrite X-Forwarded-Host

        If this function is enabled, X-Forwarded-Host will be rewritten using the Host field in the client request body and transferred to backend servers.

        This parameter is available only after HTTP/HTTPS is enabled on the listener port of a dedicated load balancer.

        Data Compression

        If this function is enabled, specific files will be compressed. If you do not enable this function, files will not be compressed.

        • Brotli can compress all file formats.
        • GZIP can compress the files in the following format:

          text, xml text, plain text, css application, javascript application, x-javascript application, rss+xml application, atom+xml application, xml application, or json

        This parameter is available only after HTTP/HTTPS is enabled on the listener port of a dedicated load balancer.

        Idle Timeout (s)

        Timeout for an idle client connection. If there are no requests reaching the load balancer during the timeout duration, the load balancer will disconnect the connection from the client and establish a new connection when there is a new request.

        This configuration is not supported if the port of a shared load balancer uses UDP.

        Request Timeout (s)

        Timeout for waiting for a request from a client. There are two cases:

        • If the client fails to send a request header to the load balancer during the timeout duration, the request will be interrupted.
        • If the interval between two consecutive request bodies reaching the load balancer is greater than the timeout duration, the connection will be disconnected.

        This parameter is available only after HTTP/HTTPS is enabled on ports.

        Response Timeout (s)

        Timeout for waiting for a response from a backend server. After a request is forwarded to the backend server, if the backend server does not respond during the timeout duration, the load balancer will stop waiting and return HTTP 504 Gateway Timeout.

        This parameter is available only after HTTP/HTTPS is enabled on ports.

        HTTP2

        Whether to use HTTP/2 for a client to communicate with a load balancer. Request forwarding using HTTP/2 improves the access performance between your application and the load balancer. However, the load balancer still uses HTTP/1.x to forward requests to the backend server.

        This parameter is available only after HTTPS is enabled on ports.

    • Annotation: The LoadBalancer Service has some advanced CCE functions, which are implemented by annotations. For details, see Using Annotations to Balance Load.

  4. Click OK.

Using kubectl to Create a Service (Using an Existing Load Balancer)

You can configure Service access when creating a workload using kubectl. This section uses an Nginx workload as an example to describe how to add a LoadBalancer Service using kubectl.

  1. Use kubectl to connect to the cluster. For details, see Connecting to a Cluster Using kubectl.
  2. Create and edit the nginx-deployment.yaml and nginx-elb-svc.yaml files.

    The file names are user-defined. nginx-deployment.yaml and nginx-elb-svc.yaml are merely example file names.

    vi nginx-deployment.yaml

    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: nginx
      template:
        metadata:
          labels:
            app: nginx
        spec:
          containers:
          - image: nginx 
            name: nginx
          imagePullSecrets:
          - name: default-secret

    vi nginx-elb-svc.yaml

    Before enabling sticky session, ensure that the following conditions are met:

    • The workload protocol is TCP.
    • Anti-affinity has been configured between pods of the workload. That is, all pods of the workload are deployed on different nodes. For details, see Scheduling Policies (Affinity/Anti-affinity).
    apiVersion: v1 
    kind: Service 
    metadata: 
      name: nginx
      annotations:
        kubernetes.io/elb.id: <your_elb_id>                         # Load balancer ID. Replace it with the actual value.
        kubernetes.io/elb.class: performance                   # Load balancer type
        kubernetes.io/elb.lb-algorithm: ROUND_ROBIN                   # Load balancer algorithm
        kubernetes.io/elb.session-affinity-mode: SOURCE_IP          # The sticky session type is source IP address.
        kubernetes.io/elb.session-affinity-option: '{"persistence_timeout": "30"}'     # Stickiness duration (min)
        kubernetes.io/elb.health-check-flag: 'on'                   # Enable ELB health check.
        kubernetes.io/elb.health-check-option: '{
          "protocol":"TCP",
          "delay":"5",
          "timeout":"10",
          "max_retries":"3"
        }'
    spec:
      selector: 
         app: nginx
      ports: 
      - name: service0 
        port: 80     # Port for accessing the Service, which is also the listener port on the load balancer.
        protocol: TCP 
        targetPort: 80  # Port used by a Service to access the target container. This port is closely related to the applications running in a container.
        nodePort: 31128  # Port number of the node. If this parameter is not specified, a random port number ranging from 30000 to 32767 is generated.
      type: LoadBalancer

    The preceding example uses annotations to implement some advanced functions of load balancing, such as sticky session and health check. For details, see Table 3.

    For more annotations and examples related to advanced functions, see Using Annotations to Balance Load.

    Table 3 annotations parameters

    Parameter

    Mandatory

    Type

    Description

    kubernetes.io/elb.id

    Yes

    String

    ID of an enhanced load balancer.

    Mandatory when an existing load balancer is to be associated.

    How to obtain:

    On the management console, click Service List, and choose Networking > Elastic Load Balance. Click the name of the target load balancer. On the Summary tab page, find and copy the ID.

    NOTE:

    The system preferentially connects to the load balancer based on the kubernetes.io/elb.id field. If this field is not specified, the spec.loadBalancerIP field is used (optional and available only in 1.23 and earlier versions).

    Do not use the spec.loadBalancerIP field to connect to the load balancer. This field will be discarded by Kubernetes. For details, see Deprecation.

    kubernetes.io/elb.class

    Yes

    String

    Select a proper load balancer type.

    The value can be:

    NOTE:

    If a LoadBalancer Service accesses an existing dedicated load balancer, the dedicated load balancer must support TCP/UDP networking.

    kubernetes.io/elb.lb-algorithm

    No

    String

    Specifies the load balancing algorithm of the backend server group. The default value is ROUND_ROBIN.

    Options:

    • ROUND_ROBIN: weighted round robin algorithm
    • LEAST_CONNECTIONS: weighted least connections algorithm
    • SOURCE_IP: source IP hash algorithm
    NOTE:

    If this parameter is set to SOURCE_IP, the weight setting (weight field) of backend servers bound to the backend server group is invalid, and sticky session cannot be enabled.

    kubernetes.io/elb.session-affinity-mode

    No

    String

    Source IP address-based sticky session means that access requests from the same IP address are forwarded to the same backend server.

    • Disabling sticky session: Do not configure this parameter.
    • Enabling sticky session: Set this parameter to SOURCE_IP, indicating that the sticky session is based on the source IP address.
    NOTE:

    When kubernetes.io/elb.lb-algorithm is set to SOURCE_IP (source IP hash), sticky session cannot be enabled.

    kubernetes.io/elb.session-affinity-option

    No

    Table 4 object

    Sticky session timeout.

    kubernetes.io/elb.health-check-flag

    No

    String

    Whether to enable the ELB health check.

    • Enabling health check: Leave blank this parameter or set it to on.
    • Disabling health check: Set this parameter to off.

    If this parameter is enabled, the kubernetes.io/elb.health-check-option field must also be specified at the same time.

    kubernetes.io/elb.health-check-option

    No

    Table 5 object

    ELB health check configuration items.

    Table 4 elb.session-affinity-option data structure

    Parameter

    Mandatory

    Type

    Description

    persistence_timeout

    Yes

    String

    Sticky session timeout, in minutes. This parameter is valid only when elb.session-affinity-mode is set to SOURCE_IP.

    Value range: 1 to 60. Default value: 60

    Table 5 elb.health-check-option data structure

    Parameter

    Mandatory

    Type

    Description

    delay

    No

    String

    Health check interval (s)

    Value range: 1 to 50. Default value: 5

    timeout

    No

    String

    Health check timeout, in seconds.

    Value range: 1 to 50. Default value: 10

    max_retries

    No

    String

    Maximum number of health check retries.

    Value range: 1 to 10. Default value: 3

    protocol

    No

    String

    Health check protocol.

    Value options: TCP or HTTP

    path

    No

    String

    Health check URL. This parameter needs to be configured when the protocol is HTTP.

    Default value: /

    Value range: 1-80 characters

  3. Create a workload.

    kubectl create -f nginx-deployment.yaml

    If information similar to the following is displayed, the workload has been created.

    deployment/nginx created

    kubectl get pod

    If information similar to the following is displayed, the workload is running.

    NAME                     READY     STATUS             RESTARTS   AGE
    nginx-2601814895-c1xhw   1/1       Running            0          6s

  4. Create a Service.

    kubectl create -f nginx-elb-svc.yaml

    If information similar to the following is displayed, the Service has been created.

    service/nginx created

    kubectl get svc

    If information similar to the following is displayed, the access type has been set, and the workload is accessible.

    NAME         TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
    kubernetes   ClusterIP      10.247.0.1       <none>        443/TCP        3d
    nginx        LoadBalancer   10.247.130.196   10.78.42.242   80:31540/TCP   51s

  5. Enter the URL in the address box of the browser, for example, 10.78.42.242:80. 10.78.42.242 indicates the IP address of the load balancer, and 80 indicates the access port displayed on the CCE console.

    The Nginx is accessible.

    Figure 3 Accessing Nginx through the LoadBalancer Service

Using kubectl to Create a Service (Automatically Creating a Load Balancer)

You can configure Service access when creating a workload using kubectl. This section uses an Nginx workload as an example to describe how to add a LoadBalancer Service using kubectl.

  1. Use kubectl to connect to the cluster. For details, see Connecting to a Cluster Using kubectl.
  2. Create and edit the nginx-deployment.yaml and nginx-elb-svc.yaml files.

    The file names are user-defined. nginx-deployment.yaml and nginx-elb-svc.yaml are merely example file names.

    vi nginx-deployment.yaml
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: nginx
      template:
        metadata:
          labels:
            app: nginx
        spec:
          containers:
          - image: nginx 
            name: nginx
          imagePullSecrets:
          - name: default-secret

    vi nginx-elb-svc.yaml

    Before enabling sticky session, ensure that the following conditions are met:

    • The workload protocol is TCP.
    • Anti-affinity has been configured between pods of the workload. That is, all pods of the workload are deployed on different nodes. For details, see Scheduling Policies (Affinity/Anti-affinity).
    Example of a Service using a public network shared load balancer:
    apiVersion: v1 
    kind: Service 
    metadata: 
      annotations:   
        kubernetes.io/elb.class: union
        kubernetes.io/elb.autocreate: '{
          "type": "public",
          "bandwidth_name": "cce-bandwidth-1551163379627",
          "bandwidth_chargemode": "bandwidth",
          "bandwidth_size": 5,
          "bandwidth_sharetype": "PER",
          "vip_subnet_cidr_id": "*****",
          "vip_address": "**.**.**.**",
          "eip_type": "5_bgp"
        }'
        kubernetes.io/elb.enterpriseID: '0'       # ID of the enterprise project to which the load balancer belongs
        kubernetes.io/elb.lb-algorithm: ROUND_ROBIN                   # Load balancer algorithm
        kubernetes.io/elb.session-affinity-mode: SOURCE_IP          # The sticky session type is source IP address.
        kubernetes.io/elb.session-affinity-option: '{"persistence_timeout": "30"}'     # Stickiness duration (min)
        kubernetes.io/elb.health-check-flag: 'on'                   # Enable ELB health check.
        kubernetes.io/elb.health-check-option: '{
          "protocol":"TCP",
          "delay":"5",
          "timeout":"10",
          "max_retries":"3"
        }'
        kubernetes.io/elb.tags: key1=value1,key2=value2           # ELB resource tags
      labels: 
        app: nginx 
      name: nginx 
    spec: 
      ports: 
      - name: service0 
        port: 80
        protocol: TCP 
        targetPort: 80
      selector: 
        app: nginx 
      type: LoadBalancer
    Example Service using a public network dedicated load balancer (only for clusters of v1.17 and later):
    apiVersion: v1
    kind: Service
    metadata:
      name: nginx
      labels:
        app: nginx
      namespace: default
      annotations:
        kubernetes.io/elb.class: performance
        kubernetes.io/elb.autocreate: '{
          "type": "public",
          "bandwidth_name": "cce-bandwidth-1626694478577",
          "bandwidth_chargemode": "bandwidth",
          "bandwidth_size": 5,
          "bandwidth_sharetype": "PER",
          "eip_type": "5_bgp",
          "vip_subnet_cidr_id": "*****",
          "vip_address": "**.**.**.**",
          "elb_virsubnet_ids": ["*****"],
          "ipv6_vip_virsubnet_id": "*****",
          "available_zone": [
             ""
          ],
          "l4_flavor_name": "L4_flavor.elb.s1.small"
        }'
        kubernetes.io/elb.enterpriseID: '0'       # ID of the enterprise project to which the load balancer belongs
        kubernetes.io/elb.lb-algorithm: ROUND_ROBIN                   # Load balancer algorithm
        kubernetes.io/elb.session-affinity-mode: SOURCE_IP          # The sticky session type is source IP address.
        kubernetes.io/elb.session-affinity-option: '{"persistence_timeout": "30"}'     # Stickiness duration (min)
        kubernetes.io/elb.health-check-flag: 'on'                   # Enable ELB health check.
        kubernetes.io/elb.health-check-option: '{
          "protocol":"TCP",
          "delay":"5",
          "timeout":"10",
          "max_retries":"3"
        }'
        kubernetes.io/elb.tags: key1=value1,key2=value2           # ELB resource tags
    spec:
      selector:
        app: nginx
      ports:
      - name: cce-service-0
        targetPort: 80
        nodePort: 0
        port: 80
        protocol: TCP
      type: LoadBalancer

    The preceding example uses annotations to implement some advanced functions of load balancing, such as sticky session and health check. For details, see Table 6.

    For more annotations and examples related to advanced functions, see Using Annotations to Balance Load.

    Table 6 annotations parameters

    Parameter

    Mandatory

    Type

    Description

    kubernetes.io/elb.class

    Yes

    String

    Select a proper load balancer type.

    The value can be:

    kubernetes.io/elb.autocreate

    Yes

    elb.autocreate object

    Whether to automatically create a load balancer associated with the Service.

    Example

    • If a public network load balancer will be automatically created, set this parameter to the following value:

      '{"type":"public","bandwidth_name":"cce-bandwidth-1551163379627","bandwidth_chargemode":"bandwidth","bandwidth_size":5,"bandwidth_sharetype":"PER","eip_type":"5_bgp","name":"james"}'

    • If a private network load balancer will be automatically created, set this parameter to the following value:

      {"type":"inner","name":"A-location-d-test"}

    kubernetes.io/elb.subnet-id

    None

    String

    ID of the subnet where the cluster is located. The value can contain 1 to 100 characters.

    • Mandatory when a cluster of v1.11.7-r0 or earlier is to be automatically created.
    • Optional for clusters later than v1.11.7-r0.

    For details about how to obtain the value, see What Is the Difference Between the VPC Subnet API and the OpenStack Neutron Subnet API?

    kubernetes.io/elb.enterpriseID

    No

    String

    Clusters of v1.15 and later versions support this field. In clusters earlier than v1.15, load balancers are created in the default project by default.

    This parameter indicates the ID of the enterprise project in which the ELB load balancer will be created.

    If this parameter is not specified or is set to 0, resources will be bound to the default enterprise project.

    How to obtain:

    Log in to the management console and choose Enterprise > Project Management on the top menu bar. In the list displayed, click the name of the target enterprise project, and copy the ID on the enterprise project details page.

    kubernetes.io/elb.lb-algorithm

    No

    String

    Specifies the load balancing algorithm of the backend server group. The default value is ROUND_ROBIN.

    Options:

    • ROUND_ROBIN: weighted round robin algorithm
    • LEAST_CONNECTIONS: weighted least connections algorithm
    • SOURCE_IP: source IP hash algorithm
    NOTE:

    If this parameter is set to SOURCE_IP, the weight setting (weight field) of backend servers bound to the backend server group is invalid, and sticky session cannot be enabled.

    kubernetes.io/elb.session-affinity-mode

    No

    String

    Source IP address-based sticky session means that access requests from the same IP address are forwarded to the same backend server.

    • Disabling sticky session: Do not configure this parameter.
    • Enabling sticky session: Set this parameter to SOURCE_IP, indicating that the sticky session is based on the source IP address.
    NOTE:

    When kubernetes.io/elb.lb-algorithm is set to SOURCE_IP (source IP hash), sticky session cannot be enabled.

    kubernetes.io/elb.session-affinity-option

    No

    Table 4 object

    Sticky session timeout.

    kubernetes.io/elb.health-check-flag

    No

    String

    Whether to enable the ELB health check.

    • Enabling health check: Leave blank this parameter or set it to on.
    • Disabling health check: Set this parameter to off.

    If this parameter is enabled, the kubernetes.io/elb.health-check-option field must also be specified at the same time.

    kubernetes.io/elb.health-check-option

    No

    Table 5 object

    ELB health check configuration items.

    kubernetes.io/elb.tags

    No

    String

    Whether to add resource tags to a load balancer. This function is available only when the load balancer is automatically created, and the cluster is of v1.23.11-r0, v1.25.6-r0, v1.27.3-r0, or later.

    A tag is in the format of "key=value". Use commas (,) to separate multiple tags.

    Table 7 elb.autocreate data structure

    Parameter

    Mandatory

    Type

    Description

    name

    No

    String

    Name of the automatically created load balancer.

    The value can contain 1 to 64 characters. Only letters, digits, underscores (_), hyphens (-), and periods (.) are allowed.

    Default: cce-lb+service.UID

    type

    No

    String

    Network type of the load balancer.

    • public: public network load balancer
    • inner: private network load balancer

    Default: inner

    bandwidth_name

    Yes for public network load balancers

    String

    Bandwidth name. The default value is cce-bandwidth-******.

    The value can contain 1 to 64 characters. Only letters, digits, underscores (_), hyphens (-), and periods (.) are allowed.

    bandwidth_chargemode

    No

    String

    Bandwidth billing mode.

    • bandwidth: billed by bandwidth
    • traffic: billed by traffic

    Default: bandwidth

    bandwidth_size

    Yes for public network load balancers

    Integer

    Bandwidth size. The value ranges from 1 Mbit/s to 2000 Mbit/s by default. Configure this parameter based on the bandwidth range allowed in your region.

    The minimum increment for bandwidth adjustment varies depending on the bandwidth range.
    • The minimum increment is 1 Mbit/s if the allowed bandwidth does not exceed 300 Mbit/s.
    • The minimum increment is 50 Mbit/s if the allowed bandwidth ranges from 300 Mbit/s to 1000 Mbit/s.
    • The minimum increment is 500 Mbit/s if the allowed bandwidth exceeds 1000 Mbit/s.

    bandwidth_sharetype

    Yes for public network load balancers

    String

    Bandwidth sharing mode.

    • PER: dedicated bandwidth

    eip_type

    Yes for public network load balancers

    String

    EIP type.

    • 5_telcom: China Telecom
    • 5_union: China Unicom
    • 5_bgp: dynamic BGP
    • 5_sbgp: static BGP

    The specific type varies with regions. For details, see the EIP console.

    vip_subnet_cidr_id

    No

    String

    Subnet where a load balancer is located. The subnet must belong to the VPC where the cluster resides.

    If this parameter is not specified, the ELB load balancer and the cluster are in the same subnet.

    This field can be specified only for clusters of v1.21 or later.

    vip_address

    No

    String

    Private IP address of the load balancer. Only IPv4 addresses are supported.

    The IP address must be in the ELB CIDR block. If this parameter is not specified, an IP address will be automatically assigned from the ELB CIDR block.

    This parameter is available only in clusters of v1.23.11-r0, v1.25.6-r0, v1.27.3-r0, or later versions.

    available_zone

    Yes

    Array of strings

    AZ where the load balancer is located.

    You can obtain all supported AZs by querying the AZ list.

    This parameter is available only for dedicated load balancers.

    l4_flavor_name

    Yes

    String

    Flavor name of the layer-4 load balancer.

    You can obtain all supported types by querying the flavor list.

    This parameter is available only for dedicated load balancers.

    l7_flavor_name

    No

    String

    Flavor name of the layer-7 load balancer.

    You can obtain all supported types by querying the flavor list.

    This parameter is available only for dedicated load balancers. The value of this parameter must be the same as that of l4_flavor_name, that is, both are elastic specifications or fixed specifications.

    elb_virsubnet_ids

    No

    Array of strings

    Subnet where the backend server of the load balancer is located. If this parameter is left blank, the default cluster subnet is used. Load balancers occupy different number of subnet IP addresses based on their specifications. Do not use the subnet CIDR blocks of other resources (such as clusters and nodes) as the load balancer CIDR block.

    This parameter is available only for dedicated load balancers.

    Example:

    "elb_virsubnet_ids": [
       "14567f27-8ae4-42b8-ae47-9f847a4690dd"
     ]

    ipv6_vip_virsubnet_id

    No

    String

    Specifies the ID of the IPv6 subnet where the load balancer resides. IPv6 must be enabled for the corresponding subnet. This parameter is mandatory only when the dual-stack clusters are used.

    This parameter is available only for dedicated load balancers.

  3. Create a workload.

    kubectl create -f nginx-deployment.yaml

    If information similar to the following is displayed, the workload is being created.

    deployment/nginx created

    kubectl get pod

    If information similar to the following is displayed, the workload is running.

    NAME                     READY     STATUS             RESTARTS   AGE
    nginx-2601814895-c1xhw   1/1       Running            0          6s

  4. Create a Service.

    kubectl create -f nginx-elb-svc.yaml

    If information similar to the following is displayed, the Service has been created.

    service/nginx created

    kubectl get svc

    If information similar to the following is displayed, the access type has been set, and the workload is accessible.

    NAME         TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
    kubernetes   ClusterIP      10.247.0.1       <none>        443/TCP        3d
    nginx        LoadBalancer   10.247.130.196   10.78.42.242   80:31540/TCP   51s

  5. Enter the URL in the address box of the browser, for example, 10.78.42.242:80. 10.78.42.242 indicates the IP address of the load balancer, and 80 indicates the access port displayed on the CCE console.

    The Nginx is accessible.

    Figure 4 Accessing Nginx through the LoadBalancer Service