Port mappings allow containers to access ports on the host container instance to
send or receive traffic. Port mappings are specified as part of the container
definition. After a task reaches the
RUNNING status, manual and automatic
host and container port assignments are visible in the
section of DescribeTasks API responses.
The port number on the container that is bound to the user-specified or automatically assigned host port. If you specify a container port and not a host port, your container automatically receives a host port in the ephemeral port range (for more information, see
hostPort). Port mappings that are automatically assigned in this way do not count toward the 100 reserved ports limit of a container instance.
The port number on the container instance to reserve for your container. You can specify a non-reserved host port for your container port mapping, or you can omit the
hostPort(or set it to
0) while specifying a
containerPortand your container automatically receives a port in the ephemeral port range for your container instance operating system and Docker version.
The default ephemeral port range is 49153 to 65535, and this range is used for Docker versions prior to 1.6.0. For Docker version 1.6.0 and later, the Docker daemon tries to read the ephemeral port range from
/proc/sys/net/ipv4/ip_local_port_range; if this kernel parameter is unavailable, the default ephemeral port range is used. You should not attempt to specify a host port in the ephemeral port range, because these are reserved for automatic assignment. In general, ports below 32768 are outside of the ephemeral port range.
The default reserved ports are 22 for SSH, the Docker ports 2375 and 2376, and the Amazon ECS container agent ports 51678 and 51679. Any host port that was previously specified in a running task is also reserved while the task is running (after a task stops, the host port is released).The current reserved ports are displayed in the
remainingResourcesof DescribeContainerInstances output, and a container instance may have up to 100 reserved ports at a time, including the default reserved ports (automatically assigned ports do not count toward the 100 reserved ports limit).
The protocol used for the port mapping. Valid values are
udp. The default is
tcp | udp
For more information about using this API in one of the language-specific AWS SDKs, see the following: