test: reshape proxy regression to a customer-experience end-to-end test

The earlier commit introspected RapidClient#build_client directly, which
overlapped with the unit tests already added in PR #68. Per review
feedback, replace it with a customer-shaped test: bind RIE Runtime API
to the container's own non-loopback hostname (so Ruby's URI.find_proxy
does not silently bypass the proxy for loopback), set HTTP_PROXY on the
image to an unreachable address, and have the handler simply return
"success".

With the fix the RIC bypasses HTTP_PROXY and the handler runs; without
it the RIC tries the unreachable proxy for next_invocation and every
suite in the image fails.

Author: maxday

Dockerfile.test

@@ -5,4 +5,18 @@ ADD test/dockerized/tasks /var/task
 RUN gem uninstall aws_lambda_ric --executables
 ADD pkg /tmp/pkg
 RUN gem install /tmp/pkg/aws_lambda_ric-*.gem
-RUN rm -rf /tmp/pkg
+RUN rm -rf /tmp/pkg
+
+# Route every HTTP call in the container through an unreachable proxy. The
+# whole suite runs with this: after the fix the RIC bypasses it for Runtime
+# API traffic and every test still passes; before the fix the RIC would
+# try to reach 127.0.0.1:1, connect refused, and every test would fail.
+ENV HTTP_PROXY=http://127.0.0.1:1
+ENV http_proxy=http://127.0.0.1:1
+
+# Custom entrypoint binds RIE's Runtime API to the container's own hostname
+# (a non-loopback address), so Ruby's URI.find_proxy loopback bypass does
+# not silently hide the bug.
+COPY test/dockerized/entrypoint.sh /entrypoint.sh
+RUN chmod +x /entrypoint.sh
+ENTRYPOINT ["/entrypoint.sh"]

test/dockerized/entrypoint.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+# Copyright 2026 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+
+set -eu
+
+if [ "$#" -ne 1 ]; then
+  echo "entrypoint requires the handler name as first argument" 1>&2
+  exit 142
+fi
+export _HANDLER="$1"
+
+# Resolve the container's own hostname to its non-loopback IPv4 (docker
+# writes this to /etc/hosts for us on eth0).
+RIC_HOST="$(getent hosts "$HOSTNAME" | awk '{print $1; exit}')"
+if [ -z "$RIC_HOST" ]; then
+  echo "entrypoint could not resolve \$HOSTNAME ($HOSTNAME)" 1>&2
+  exit 143
+fi
+
+exec /usr/local/bin/aws-lambda-rie \
+    --runtime-api-address "$RIC_HOST:9001" \
+    /var/runtime/bootstrap

test/dockerized/suites/proxy.json

@@ -6,10 +6,7 @@
             "request": {},
             "assertions": [
                 {
-                    "response": {
-                        "baseline_uses_proxy": true,
-                        "ric_bypasses_proxy": true
-                    }
+                    "response": "success"
                 }
             ]
         }

test/dockerized/tasks/proxy.rb

@@ -1,28 +1,12 @@
-require 'aws_lambda_ric/lambda_server'
-require 'net/http'
-require 'uri'
+# Copyright 2026 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# The image (see Dockerfile.test) runs with HTTP_PROXY pointed at an
+# unreachable address and RIE's Runtime API bound to a non-loopback
+# hostname. If the proxy-bypass fix (PR #68) is in place the RIC bypasses
+# HTTP_PROXY for Runtime API calls and this handler runs to completion,
+# returning "success". Without the fix the RIC would try to reach the
+# unreachable proxy for next_invocation and this handler would never run.
 
 def check_proxy_bypass(event:, context:)
-  original_http_proxy = ENV['HTTP_PROXY']
-  original_https_proxy = ENV['HTTPS_PROXY']
-  ENV['HTTP_PROXY'] = 'http://proxy.example.invalid:3128'
-  ENV['HTTPS_PROXY'] = 'http://proxy.example.invalid:3128'
-
-  uri = URI('http://169.254.100.1:9001/2018-06-01/runtime/invocation/next')
-
-  # Baseline: a bare Net::HTTP.new (the pre-fix pattern) DOES pick up
-  # HTTP_PROXY via :ENV proxy resolution for this non-loopback host.
-  baseline_client = Net::HTTP.new(uri.host, uri.port)
-
-  # Under test: RapidClient#build_client MUST NOT pick up HTTP_PROXY.
-  rapid_client = RapidClient.new('169.254.100.1:9001', 'ric-proxy-regression')
-  under_test = rapid_client.send(:build_client, uri)
-
-  {
-    baseline_uses_proxy: baseline_client.proxy?,
-    ric_bypasses_proxy: !under_test.proxy?
-  }
-ensure
-  ENV['HTTP_PROXY'] = original_http_proxy
-  ENV['HTTPS_PROXY'] = original_https_proxy
+  'success'
 end