Creating an instance group with a Container Optimized Image

    To run multiple instances of the service in Docker containers, you can create an instance group from a Container Optimized Image. In such groups, you can use VM metadata to update Docker containers.

    Warning

    When creating a group, keep the limits in mind. Not to disrupt the component Instance Groups, do not update or delete manually created resources: target group Load Balancer, virtual machines and disks. To do this, update or delete the instance group.

    By default, all operations in Instance Groups are performed on behalf of a service account. If you don't have a service account, create one.

    To create an instance group built on a Container Optimized Image:

    1. If you don't have the Yandex.Cloud command line interface yet, install it.

    2. The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name or --folder-id parameter.

    3. See the description of the CLI's create instance group command:

      $ yc compute instance-group create --help
      
    4. Check whether there are networks in the folder:

      $ yc vpc network list
      

      If there aren't any, create one.

    5. Create a YAML file with a name like specification.yaml.

    6. Select the latest version of the Container Optimized Image from the public images.

      To get the ID of the latest version of the Container Optimized Image, run the command:

      $ yc compute image get-latest-from-family container-optimized-image --folder-id standard-images
      id: <image ID>
      folder_id: standard-images
      ...
      
    7. In the specification.yaml file you created, specify the following:

      • General information about the group:

        name: container-optimized-group
        service_account_id: aje3932acd8avp6edhbt
        description: "This instance group was created from YAML config"
        

        Keys:

        Key Value
        name A name for the instance group. The name must be unique within the folder. The name may contain lowercase Latin letters, numbers, and hyphens. The first character must be a letter. The last character can't be a hyphen. The maximum length of the name is 63 characters.
        service_account_id ID of the service account.
        description A description of the instance group.
      • Instance template:

        instance_template:
            platform_id: standard-v1
            resources_spec:
                memory: 4G
                cores: 1
            boot_disk_spec:
                mode: READ_WRITE
                disk_spec:
                    image_id: fd81a49qficqvt0dthu8
                    type_id: network-hdd
                    size: 32G
            network_interface_specs:
                - network_id: c64mknqgnd8avp6edhbt
                  primary_v4_address_spec: {}
            metadata:
                docker-container-declaration: |-
                    spec:
                        containers:
                            - name: nginx
                              image: cr.yandex/mirror/nginx:1.17.4-alpine
                              securityContext:
                                privileged: false
                              tty: false
                              stdin: false
        

        The disk size is specified in bytes by default. You can specify a different unit of measurement using the applicable suffix.

        Name Example of a YAML file entry:
        Kilobyte 1073741824k
        Megabyte 1048576m
        Gigabyte 1024g
        Terabyte 1t

        Keys:

        Key Value
        platform_id Platform ID.
        memory Amount of memory (RAM).
        cores Number of processor cores (vCPUs).
        mode Disk access mode.
        - READ_ONLY: read-only access.
        - READ_WRITE: read/write access.
        image_id ID of the public Container Optimized Image.
        type_id Disk type.
        size Disk size.
        network_id The default-net ID.
        primary_v4_address_spec IPv4 specification. Only IPv4 is currently available. You can allow public access to group instances by specifying the IP version for the public IP address. For more information, see Template description in a YAML file.
        metadata Values to pass to the VM metadata.
        docker-container-declaration The key in the VM metadata to access the Docker container description.
      • Policies:

        deploy_policy:
            max_unavailable: 1
            max_expansion: 0
        scale_policy:
            fixed_scale:
                size: 3
        allocation_policy:
            zones:
                - zone_id: ru-central1-a
        

        Keys:

        Key Value
        deploy_policy Deployment policy for instances in the group.
        scale_policy Scaling policy for instances in the group.
        allocation_policy Policy for allocating instances across zones and regions.

        Full code for the specification.yaml file:

        name: container-optimized-group
        service_account_id: aje3932acd8avp6edhbt
        description: "This instance group was created from YAML config"
        instance_template:
            platform_id: standard-v1
            resources_spec:
                memory: 4G
                cores: 1
            boot_disk_spec:
                mode: READ_WRITE
                disk_spec:
                    image_id: fd81a49qficqvt0dthu8
                    type_id: network-hdd
                    size: 32G
            network_interface_specs:
                - network_id: c64mknqgnd8avp6edhbt
                  primary_v4_address_spec: {}
            metadata:
                docker-container-declaration: |-
                    spec:
                        containers:
                            - name: nginx
                              image: cr.yandex/mirror/nginx:1.17.4-alpine
                              securityContext:
                                privileged: false
                              tty: false
                              stdin: false
        deploy_policy:
            max_unavailable: 1
            max_expansion: 0
        scale_policy:
            fixed_scale:
                size: 3
        allocation_policy:
            zones:
                - zone_id: ru-central1-a
        
    8. Create an instance group in the default folder:

      $ yc compute instance-group create --file specification.yaml
      

      This command creates a group of three similar instances with the following characteristics:

      • Named container-optimized-group.
      • From the latest version of the public Container Optimized Image.
      • With a running Docker container based on cr.yandex/mirror/nginx:1.17.4-alpine.
      • In the default-net network.
      • In the ru-central1-a availability zone.
      • With a single vCPU and 4 GB RAM.
      • With a 32 GB network HDD.