feat: update ssm tunneling script

fish/theme-t31m/functions/ssm_tunnel.fish

@@ -1,4 +1,6 @@
-function ssm_tunnel --description 'access private AWS ressources via Bastion Host'
+# See: https://aws.amazon.com/about-aws/whats-new/2022/05/aws-systems-manager-support-port-forwarding-remote-hosts-using-session-manager/
+# And: https://docs.aws.amazon.com/systems-manager/latest/userguide/session-manager-working-with-sessions-start.html#sessions-remote-port-forwarding
+function ssm_tunnel --description 'Access private AWS ressources via native SSM port forwarding through bastion'
 
     if test (count $argv) -lt 2
         echo "Provide an Host:Port Mapping & an Local Port"
@@ -12,7 +14,45 @@ function ssm_tunnel --description 'access private AWS ressources via Bastion Hos
 
     # Get bastion host ID using it's name
     set INSTANCE_ID (aws ec2 describe-instances \
-            --filter 'Name=tag:Name,Values=ops-infrastructure-bastion'\
+            --filter 'Name=tag:Name,Values=INSTANCE_NAME_HERE'\
+            --query "Reservations[].Instances[?State.Name == 'running'].InstanceId[]"\
+            --output text)
+   
+    # AWS Remote host i.e internal.s.twaice / dualstack.internal-stg-s-inter-9ov8h1o4saoa-793915940.eu-west-1.elb.amazonaws.com
+    set REMOTE_HOST (string split -f1 : $argv[1])
+    set REMOTE_PORT (string split -f2 : $argv[1])
+    # Local port to bind for forwarding
+    set LOCAL_PORT $argv[2]
+
+     # Seconds until forwarding session times out (6h max)
+    set TIMEOUT 21600
+
+    # Start tunnel session
+    echo "Starting Tunnel"
+    aws ssm start-session --target $INSTANCE_ID \
+    --document-name "AWS-StartPortForwardingSessionToRemoteHost" \
+    --parameters "host=[$REMOTE_HOST],portNumber=[$REMOTE_PORT],localPortNumber=[$LOCAL_PORT]"
+
+    echo "Tunneling Session Exited."
+end
+
+# This function is for Platform Admin / Infrastructure users only.
+# @TODO: It still utilized the old style of ssm tunneling -> needs c&p of new style as well
+function ssm_tunnel_admin --description 'access private AWS ressources via Bastion Host'
+
+    if test (count $argv) -lt 2
+        echo "Provide an Host:Port Mapping & an Local Port"
+        return
+    end
+
+    if [ "$env" != "ops" ]
+        echo "Switch to OPS ENV first"
+        return
+    end
+
+    # Get bastion host ID using it's name
+    set INSTANCE_ID (aws ec2 describe-instances \
+            --filter 'Name=tag:Name,Values=INSTANCE_NAME_HERE'\
             --query "Reservations[].Instances[?State.Name == 'running'].InstanceId[]"\
             --output text)
     
@@ -40,4 +80,4 @@ function ssm_tunnel --description 'access private AWS ressources via Bastion Hos
     # stop socat on the bastion
     aws ssm cancel-command --command-id $CMD_INVOC_ID
     echo "Command Cancelled Successfully."
-end
+end