Elastic Container Instance:Obtain metadata from a container

Method 1: Use MetaServer to access metadata

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

2. Access metadata.

   Note

   If curl is not installed in the container, install curl.

   curl http://100.100.100.200/latest/meta-data/<metadata>

   Replace <metadata> with the metadata item that you want to query. For example, replace <metadata> with instance-id.

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

   The following table describes the metadata items of an elastic container instance that you can query.

   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 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 is connected.
   /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 in VPCs and to which IPv6 addresses are assigned.
   /network/interfaces/macs/[mac]/vswitch-id	The ID of the vSwitch that resides in the same VPC as the security group of the NIC.
   /network/interfaces/macs/[mac]/vpc-id	The ID of the VPC in which the security group of the NIC resides.
   /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 NIC.
   /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 elastic container instances that reside in VPCs and to which IPv6 addresses are assigned.
   /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 elastic container instances that reside within VPCs and to which IPv6 addresses are assigned.
   /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 in which the elastic container instance resides.
   /vpc-cidr-block	The CIDR block of the VPC in which the elastic container instance resides.
   /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 temporary STS credentials only after you specify a RAM role for an elastic container instance. Replace [role-name] with the name of the RAM role. If you do not replace [role-name] with the name of the RAM role, the name of the elastic container instance 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 on the instance. The metadata items of an elastic container instance that can be obtained by using this method include the instance ID, instance name, region ID of the instance, zone ID of the instance, and container name.

Examples:

ContainerGroupName=test-env
Container.1.Image=registry-vpc.cn-shanghai.aliyuncs.com/eci_open/nginx:1.14.2
Container.1.Name=container-1
# 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__

After the elastic container instance is created, you can connect to the container to check whether the configured environment variables have taken effect. For more information, see Connect to an elastic container instance.