无法将Internet与EC2实例连接到私有子网中

Question

我正在尝试在我使用Jumpbox进行SSH的私有子网中的EC2实例上安装docker。我甚至试图在我的安全组中允许所有交通，但仍然没有发生。

sudo yum update -y
Loaded plugins: priorities, update-motd, upgrade-helper
Could not retrieve mirrorlist http://repo.us-west-1.amazonaws.com/latest/main/mirror.list error was
12: Timeout on http://repo.us-west-1.amazonaws.com/latest/main/mirror.list: (28, 'Connection timed out after 5001 milliseconds')


 One of the configured repositories failed (Unknown),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Disable the repository, so yum won't use it by default. Yum will then
        just ignore the repository until you permanently enable it again or use
        --enablerepo for temporary usage:

            yum-config-manager --disable <repoid>

     4. Configure the failing repository to be skipped, if it is unavailable.
        Note that yum will try to contact the repo. when it runs most commands,
        so will have to try and fail each time (and thus. yum will be be much
        slower). If it is a very temporary problem though, this is often a nice
        compromise:

            yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true

Cannot find a valid baseurl for repo: amzn-main/latest

Answer 1

私有子网中的Amazon EC2实例无法直接与Internet通信。这是故意的，因为它是私有子网。

要允许此类连接：

• 在同一VPC中的公有子网中创建NAT网关
• 修改私有子网的路由表，将流量目标0.0.0.0/0定向到NAT网关

当EC2实例尝试访问Internet时，其请求将被发送到NAT网关。 NAT网关将代表实例发出请求，并将响应发送回实例。这允许向Internet的出站连接，同时保护实例免受入站连接的影响。

使用私有子网并不是绝对必要的。安全组可以在实例级别而不是在子网级别执行类似的功能。