ec2-instance-connect open-tunnel failed when NO_PROXY not set.

[sayurin]

Describe the bug

ec2-instance-connect open-tunnel failed when NO_PROXY not set.

Expected Behavior

open-tunnel successfully connected.

Current Behavior

following error message.

2023-07-07 17:47:08,068 - MainThread - awscli.clidriver - DEBUG - Exception caught in main()
Traceback (most recent call last):
  File "awscli\clidriver.py", line 460, in main
  File "awscli\clidriver.py", line 595, in __call__
  File "awscli\customizations\commands.py", line 205, in __call__
  File "awscli\customizations\ec2instanceconnect\opentunnel.py", line 145, in _run_main
  File "awscli\customizations\ec2instanceconnect\websocket.py", line 326, in run
  File "awscli\customizations\ec2instanceconnect\websocket.py", line 363, in _open_websocket_connection
  File "awscli\customizations\ec2instanceconnect\websocket.py", line 158, in connect
TypeError: argument of type 'NoneType' is not iterable

argument of type 'NoneType' is not iterable
kex_exchange_identification: Connection closed by remote host

Reproduction Steps

1. Setup EC2 Instance, EC2 Instance Connect and EC2 Instance Connect Endpoint. (Instance ID as i-xxxx).
2. Setup HTTP Proxy (Proxy address as proxy.example.com:8080).
3. Set environment variable HTTP_PROXY to use proxy.
   In bash, export HTTP_PROXY=http://proxy.example.com:8080.
   In PowerShell $env:HTTP_PROXY="http://proxy.example.com:8080".
4. Unset env NO_PROXY.
   In bash, unset NO_PROXY.
   In PowerShell, $env:NO_PROXY="".
5. Run aws cli aws ec2-instance-connect ssh --connection-type eice --instance-id i-xxxx --debug.
   This will fail with the error written at Current Behavior.

Workarround,

1. Set environment variable NO_PROXY to dummy value.
   In bash, export NO_PROXY=1.
   In PowerShell, $env:NO_PROXY="1".
2. Run aws cli aws ec2-instance-connect ssh --connection-type eice --instance-id i-xxxx --debug.
   This will success as expected behavior.

Possible Solution

aws-cli/awscli/customizations/ec2instanceconnect/websocket.py

Lines 157 to 158 in 03e3028

	no_proxy = environment.get("NO_PROXY")
	if proxy_url and parsed_url.hostname not in no_proxy:

If environment variable NO_PROXY is not set, no_proxy become NoneType.

Additional Information/Context

For workaround, set environment variable NO_PROXY with dummy value.

CLI version used

4.12.7

Environment details (OS name and version, etc.)

Windows and CloudShell.

[tim-finnigan]

Hi @sayurin thanks for reaching out. I'm having trouble reproducing this issue, could you share your debug logs (with any sensitive info redacted) by adding --debug to your command?

[sayurin]

@tim-finnigan I updated description, repro steps. Please try with --connection-type eice option.

[tim-finnigan]

Thanks for following up, I can reproduce the issue now. We will reach out to the team working this customization for next steps.

[tim-finnigan]

Closing as #8039 was merged, please update to v2.13.2+ per the CHANGELOG and let us know if you run into any issues. Thanks again for reporting this!

[github-actions]

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