Elastic Container Instance:Obtain the metadata from a container

Method 1: Use MetaServer to access metadata

You can perform the following operations to obtain the metadata of an elastic container instance:

1. Connect to a container. For more information, see Connect to an elastic container instance.

2. Run the following command to access the root directory of the metadata:

   curl http://100.100.100.200/latest/meta-data/

3. Append the name of a metadata item to the command to obtain the information about the item.

   For example, run the following command to obtain the ID of the elastic container instance:

   curl http://100.100.100.200/latest/meta-data/instance-id

   The following table describes the metadata items that you can obtain for an elastic container instance.

   Metadata item	Description
   /dns-conf/nameservers	The Domain Name System (DNS) configurations of the elastic container instance.
   /eipv4	The elastic IPv4 address of the elastic container instance.
   /hostname	The hostname of the elastic container instance, which is the ContainerGroupName value.
   /instance-id	The ID of the elastic container instance.
   /mac	The media access control (MAC) address of the elastic container instance.
   /network/interfaces/	The MAC addresses of the network interface controllers (NICs).
   /network/interfaces/macs/[mac]/network-interface-id	The ID of the NIC. Replace [mac] with the MAC address of the elastic container instance.
   /network/interfaces/macs/[mac]/netmask	The subnet mask of the NIC.
   /network/interfaces/macs/[mac]/vswitch-cidr-block	The IPv4 CIDR block of the vSwitch to which the NIC belongs.
   /network/interfaces/macs/[mac]/vpc-cidr-block	The IPv4 CIDR block of the virtual private cloud (VPC) to which the NIC belongs.
   /network/interfaces/macs/[mac]/private-ipv4s	The private IPv4 addresses assigned to the NIC.
   /network/interfaces/macs/[mac]/vpc-ipv6-cidr-blocks	The IPv6 CIDR block of the VPC to which the NIC belongs. This item is applicable only to the elastic container instances that reside within VPCs and are assigned IPv6 addresses.
   /network/interfaces/macs/[mac]/vswitch-id	The ID of a vSwitch in the VPC to which the security group of the NIC belongs.
   /network/interfaces/macs/[mac]/vpc-id	The ID of the VPC to which the security group of the NIC belongs.
   /network/interfaces/macs/[mac]/primary-ip-address	The primary private IP address of the NIC.
   /network/interfaces/macs/[mac]/gateway	The IPv4 gateway address of the VPC to which the NIC belongs.
   /instance/max-netbw-egress	The maximum outbound internal bandwidth of the elastic container instance. Unit: Kbit/s.
   /instance/max-netbw-ingerss	The maximum inbound internal bandwidth of the elastic container instance. Unit: Kbit/s.
   /network/interfaces/macs/[mac]/ipv6s	The IPv6 addresses assigned to the NIC. This item is applicable only to the elastic container instances that reside within VPCs and are assigned IPv6 addresses.
   /network/interfaces/macs/[mac]/ipv6-gateway	The IPv6 gateway address of the VPC to which the NIC belongs.
   /network/interfaces/macs/[mac]/vswitch-ipv6-cidr-block	The IPv6 CIDR block of the vSwitch to which the NIC is connected. This item is applicable only to the elastic container instances that reside within VPCs and are assigned IPv6 addresses.
   /private-ipv4	The private IPv4 address of the elastic container instance.
   /ntp-conf/ntp-servers	The address of the Network Time Protocol (NTP) server.
   /owner-account-id	The ID of the Alibaba Cloud account to which the elastic container instance belongs.
   /region-id	The region ID of the elastic container instance.
   /serial-number	The serial number of the elastic container instance.
   /vpc-id	The ID of the VPC to which the elastic container instance belongs.
   /vpc-cidr-block	The CIDR block of the VPC to which the elastic container instance belongs.
   /vswitch-cidr-block	The CIDR block of the vSwitch to which the elastic container instance is connected.
   /vswitch-id	The ID of the vSwitch to which the elastic container instance is connected.
   /zone-id	The zone ID of the elastic container instance.
   /ram/security-credentials/[role-name]	The temporary Security Token Service (STS) credentials generated for the Resource Access Management (RAM) role of the elastic container instance. You can obtain the STS credentials only after you specify a RAM role to an elastic container instance. Replace [role-name] with the name of the RAM role. If [role-name] is not specified, the name of the RAM role is returned.

Method 2: Configure environment variables for a container

You can obtain the information about an elastic container instance by configuring environment variables for a container in the instance. The metadata items of an elastic container instance that can be obtained in this manner include the instance ID, instance name, region ID of the instance, zone ID of the instance, and container name.

params = {
        'Container.1.Image': 'registry-vpc.cn-shanghai.aliyuncs.com/eci_open/nginx:alpine',
        'Container.1.Name': 'nginx',
        'SecurityGroupId': 'sg-uf6biempwqvodk7a****',
        'VSwitchId': 'vsw-uf6mhqg2wiq9iifhn****',
        'ContainerGroupName': 'test-env',
        # Configure environment variables.
        'Container.1.EnvironmentVar.1.Key': 'eci_id',
        'Container.1.EnvironmentVar.2.Key': 'eci_name',
        'Container.1.EnvironmentVar.3.Key': 'region_id',
        'Container.1.EnvironmentVar.4.Key': 'zone_id',
        'Container.1.EnvironmentVar.5.Key': 'container_name',
        'Container.1.EnvironmentVar.1.Value': '__ECI_ID__',
        'Container.1.EnvironmentVar.2.Value': '__ECI_NAME__',
        'Container.1.EnvironmentVar.3.Value': '__REGION_ID__',
        'Container.1.EnvironmentVar.4.Value': '__ZONE_ID__',
        'Container.1.EnvironmentVar.5.Value': '__CONTAINER_NAME__',
    }

You can log on to the Elastic Container Instance console and connect to the container to check whether the configured environment variables have taken effect. For more information, see Connect to an elastic container instance.