Creating a Deployment

Scenario

Deployments are workloads (for example, Nginx) that do not store any data or status. You can create Deployments on the CCE console or by running kubectl commands.

Prerequisites

• Before creating a containerized workload, you must have an available cluster. For details on how to create a cluster, see Buying a CCE Cluster.
• To enable public access to a workload, ensure that an EIP or load balancer has been bound to at least one node in the cluster.
  

  If a pod has multiple containers, ensure that the ports used by the containers do not conflict with each other. Otherwise, creating the Deployment will fail.

Using the CCE Console

1. Log in to the CCE console. In the navigation pane, choose Workloads > Deployments. On the page displayed, click Create Deployment. Set basic workload parameters as described in Table 1. The parameters marked with an asterisk (*) are mandatory.

   Table 1 Basic workload parameters

   Parameter	Description
   * Workload Name	Name of the workload to be created. The name must be unique. Enter 4 to 63 characters starting with a letter and ending with a letter or digit. Only lowercase letters, digits, and hyphens (-) are allowed.
   * Cluster Name	Cluster to which the workload belongs.
   * Namespace	In a single cluster, data in different namespaces is isolated from each other. This enables applications to share the services of the same cluster without interfering each other. If no namespace is set, the default namespace is used.
   * Instances	Number of pods in the workload. A workload can have one or more pods. You can set the number of pods. The default value is 2 and can be set to 1. Each workload pod consists of the same containers. Configuring multiple pods for a workload ensures that the workload can still run properly even if a pod is faulty. If only one pod is used, a node or pod exception may cause service exceptions.
   Time Zone Synchronization	If this parameter is enabled, the container and the node use the same time zone. NOTICE: After time zone synchronization is enabled, disks of the hostPath type will be automatically added and listed in the Data Storage > Local Volume area. Do not modify or delete the disks.
   Description	Description of the workload.

2. Click Next: Add Container.
   1. Click Add Container and select the image to be deployed.
      • My Images: Create a workload using an image in the image repository you created.
      • Third-Party Images: Create a workload using an image from any third-party image repository. When you create a workload using a third-party image, ensure that the node where the workload is running can access public networks. For details on how to create a workload using a third-party image, see Using a Third-Party Image.
        • If your image repository does not require authentication, set Secret Authentication to No, enter an image pull address, and then click OK.
        • If your image repository must be authenticated (account and password), you need to create a secret and then use a third-party image. For details, see Using a Third-Party Image.
      • Shared Images: Create a workload using an image shared by another tenant through the SWR service.
   2. Configure basic image information.

      A workload is an abstract model of a group of pods. One pod can encapsulate one or more containers. You can click Add Container in the upper right corner to add multiple container images and set them separately.

      Table 2 Image parameters

      Parameter	Description
      Image Name	Name of the image. You can click Change Image to update it.
      *Image Version	Select the image tag to be deployed.
      *Container Name	Name of the container. You can modify it.
      Privileged Container	Programs in a privileged container have certain privileges. If Privileged Container is On, the container is granted superuser permissions. For example, privileged containers can manipulate network devices on the host machine and modify kernel parameters.
      Container Resources	CPU Request: minimum number of CPU cores required by a container. The default value is 0.25 cores. Limit: maximum number of CPU cores available for a container. Do not leave Limit unspecified. Otherwise, intensive use of container resources will occur and your workload may exhibit unexpected behavior. Memory Request: minimum amount of memory required by a container. The default value is 512 MiB. Limit: maximum amount of memory available for a container. When memory usage exceeds the specified memory limit, the container will be terminated. For more information about Request and Limit, see Setting Container Specifications. GPU: configurable only when the cluster contains GPU nodes. It indicates the percentage of GPU resources reserved for a container. Select Use and set the percentage. For example, if this parameter is set to 10%, the container is allowed to use 10% of GPU resources. If you do not select Use or set this parameter to 0, no GPU resources can be used. GPU/Graphics Card: The workload's pods will be scheduled to the node with the specified GPU. If Any GPU type is selected, the container uses a random GPU in the node. If you select a specific GPU, the container uses this GPU accordingly.

   3. Lifecycle: Commands for starting and running containers can be set.
      • Start Command: executed when the workload is started. For details, see Setting Container Startup Commands.
      • Post-Start: executed after the workload runs successfully. For more information, see Setting Container Lifecycle Parameters.
      • Pre-Stop: executed to delete logs or temporary files before the workload ends. For more information, see Setting Container Lifecycle Parameters.
   4. Health Check: CCE provides two types of probes: liveness probe and readiness probe. They are used to determine whether containers and user services are running properly. For more information, see Setting Health Check for a Container.
      • Liveness Probe: used to restart the unhealthy container.
      • Readiness Probe: used to change the container to the unready state when detecting that the container is unhealthy. In this way, service traffic will not be directed to the container.
   5. Environment Variables: Environment variables can be added to a container. In general, environment variables are used to set parameters.
      On the Environment Variables tab page, click Add Environment Variable. Currently, three types of environment variables are supported:

      • Added manually: Set Variable Name and Variable Value/Reference.
      • Added from Secret: Set Variable Name and select the desired secret name and data. A secret must be created in advance. For details, see Creating a Secret.
      • Added from ConfigMap: Set Variable Name and select the desired ConfigMap name and data. A ConfigMap must be created in advance. For details, see Creating a ConfigMap.
        

        To edit an environment variable that has been set, click Edit. To delete an environment variable that has been set, click Delete.

   6. Data Storage: Data storage can be mounted to containers for persistent storage and high disk I/O. Local volume and cloud storage are supported. For details, see Storage (CSI).
   7. Security Context: Container permissions can be configured to protect CCE and other containers from being affected.

      Enter the user ID to set container permissions and prevent systems and other containers from being affected.

   8. Log Policies: Log collection policies and log directory can be configured to collect container logs for unified management and analysis. For details, see Container Logs.

3. Click Next: Set Application Access. Then, click Add Service and set the workload access type.

   If your workload will be reachable to other workloads or public networks, add a Service to define the workload access type.

   The workload access type determines the network attributes of the workload. Workloads with different access types can provide different network capabilities. For details, see Overview.

4. Click Next: Configure Advanced Settings to configure advanced policies.
   • Upgrade Mode: You can specify the upgrade mode of a Deployment, including Rolling upgrade and In-place upgrade.
     • Rolling upgrade: Old pods are gradually replaced with new ones. During the upgrade, service traffic is evenly distributed to both pods to ensure service continuity.
       • Maximum Number of Unavailable Pods: maximum number of unavailable pods allowed in a rolling upgrade. If the number is equal to the total number of pods, services may be interrupted. Minimum number of alive pods = Total pods – Maximum number of unavailable pods
     • In-place upgrade: Old pods are deleted before new pods are created. Services will be interrupted during an in-place upgrade.
   • Graceful Deletion: A time window can be set for workload deletion and reserved for executing commands in the pre-stop phase in the lifecycle. If workload processes are not terminated after the time window elapses, the workload will be forcibly deleted.
     • Graceful Time Window (s): Set a time window (0–9999s) for pre-stop commands to finish execution before a workload is deleted. The default value is 30s.
     • Scale Order: Choose Prioritize new pods or Prioritize old pods based on service requirements. Prioritize new pods indicates that new pods will be first deleted when a scale-in is triggered.
   • Migration Policy: When the node where a workload's pods are located is unavailable for the specified amount of time, the pods will be rescheduled to other available nodes.
     • Migration Time Window (s): Set a time window for migration. The default value is 300s.
   • Scheduling Policies: You can combine static global scheduling policies or dynamic runtime scheduling policies as required. For details, see Scheduling Policy Overview.
   • Advanced Pod Settings
     • Pod Label: The built-in app label is specified when the workload is created. It is used to set affinity and anti-affinity scheduling and cannot be modified. You can click Add Label to add labels.
     Figure 1 Advanced pod settings
     
   • Client DNS Configuration: A CCE cluster has a built-in DNS add-on (CoreDNS) to provide domain name resolution for workloads in the cluster.
     • DNS Policy
       • ClusterFirst: The default DNS configuration overrides the Nameserver and DNS Search Domain configurations of the client.
       • None: Only the Nameserver and DNS Search Domain configurations are used for domain name resolution.
       • Default: The pod inherits the DNS configuration from the node on which the pod runs.
     • Nameserver: You can configure a domain name server for a user-defined domain name. The value is one or a group of DNS IP addresses, for example, 1.2.3.4.
     • DNS Search Domain: a search list for host-name lookup. When a domain name cannot be resolved, DNS queries will be attempted combining the domain name with each domain in the search list in turn until a match is found or all domains in the search list are tried.
     • Timeout (s): amount of time the resolver will wait for a response from a remote name server before retrying the query on a different name server. Set it based on the site requirements.
     • ndots: threshold for the number of dots that must appear in a domain name before an initial absolute query will be made. If a domain name has ndots or more than ndots dots, the name is a fully qualified domain name (FQDN) and will be tried first as an absolute name. If a domain name has less than ndots dots, the operating system will look up the name in a list of search domain names.

5. After the preceding configurations are complete, click Create. On the page displayed, click Return to Workload List to view the workload status.

   If the workload is in the Running state, it has been successfully created.

   Workload status is not updated in real time. Click in the upper right corner or press F5 to refresh the page.

6. To access the workload in a browser, go to the workload list on the Deployments page. Copy the corresponding External Access Address and paste it into the address box in the browser.
   

   • External access addresses are available only if the Deployment access type is set to NodePort and an EIP is assigned to any node in the cluster, or if the Deployment access type is set to LoadBalancer (ELB).
   • If the workload list contains more than 500 records, the Kubernetes pagination mechanism will be used. Specifically, you can only go to the first page or the next page, but cannot go to the previous page. In addition, if resources are divided into discrete pages, the total number of resources displayed is the maximum number of resources that can be queried at a time, not the actual total number of resources.

Using kubectl

The following procedure uses Nginx as an example to describe how to create a workload 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 file. nginx-deployment.yaml is an example file name. You can rename it as required.

   vi nginx-deployment.yaml

   The following is an example YAML file. For more information about Deployments, see Kubernetes documentation.

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: nginx
     strategy:
       type: RollingUpdate
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
         - image: nginx    # If you use an image from an open-source image registry, enter the image name. If you use an image in My Images, obtain the image path from SWR.
           imagePullPolicy: Always
           name: nginx
         imagePullSecrets:
         - name: default-secret

   For details about these parameters, see Table 3.

   Table 3 Deployment YAML parameters

   Parameter	Description	Mandatory/Optional
   apiVersion	API version. NOTE: Set this parameter based on the cluster version. For clusters of v1.17 or later, the apiVersion format of Deployments is apps/v1. For clusters of v1.15 or earlier, the apiVersion format of Deployments is extensions/v1beta1.	Mandatory
   kind	Type of a created object.	Mandatory
   metadata	Metadata of a resource object.	Mandatory
   name	Name of the Deployment.	Mandatory
   Spec	Detailed description of the Deployment.	Mandatory
   replicas	Number of pods.	Mandatory
   selector	Determines container pods that can be managed by the Deployment.	Mandatory
   strategy	Upgrade mode. Possible values: RollingUpdate ReplaceUpdate By default, rolling update is used.	Optional
   template	Detailed description of a created container pod.	Mandatory
   metadata	Metadata.	Mandatory
   labels	metadata.labels: Container labels.	Optional
   spec: containers	image (mandatory): Name of a container image. imagePullPolicy (optional): Policy for obtaining an image. The options include Always (attempting to download images each time), Never (only using local images), and IfNotPresent (using local images if they are available; downloading images if local images are unavailable). The default value is Always. name (mandatory): Container name.	Mandatory
   imagePullSecrets	Name of the secret used during image pulling. If a private image is used, this parameter is mandatory. To pull an image from the Software Repository for Container (SWR), set this parameter to default-secret. To pull an image from a third-party image repository, set this parameter to the name of the created secret.	Optional

3. Create a Deployment.

   kubectl create -f nginx-deployment.yaml

   If the following information is displayed, the Deployment is being created.

   deployment "nginx" created

4. Query the Deployment status.

   kubectl get deployment

   If the following information is displayed, the Deployment is running.

   NAME           READY     UP-TO-DATE   AVAILABLE   AGE 
   nginx          1/1       1            1           4m5s

   Parameter description

   • NAME: pod name
   • READY: number of pod replicas that have been deployed
   • STATUS: status of the Deployment
   • RESTARTS: restart times
   • AGE: period the Deployment keeps running

5. If the Deployment will be accessed through a ClusterIP or NodePort Service, add the corresponding Service. For details, see Networking.