fix(ci): isolate tests from egress proxy

.gitlab/generate-package.php

@@ -1217,6 +1217,8 @@ function appsec_image_from_tag_mapping(string $tag): string
     - pecl install datadog_trace.tgz
     - echo "extension=ddtrace.so" | sudo tee $(php -i | awk -F"=> " '/Scan this dir for additional .ini files/ {print $2}')/ddtrace.ini
     - php --ri=ddtrace
+    # The Fabric proxy changes network failure semantics in PECL tests.
+    - unset HTTP_PROXY HTTPS_PROXY http_proxy https_proxy ALL_PROXY all_proxy
     - TERM=dumb HTTPBIN_HOSTNAME=httpbin-integration HTTPBIN_PORT=8080 DATADOG_HAVE_DEV_ENV=1 DD_TRACE_GIT_METADATA_ENABLED=0 pecl run-tests --showdiff --ini=" -d datadog.trace.sources_path=" -p datadog_trace
   after_script:
     - mkdir artifacts

.gitlab/generate-tracer.php

@@ -571,6 +571,8 @@ function before_script_steps($with_docker_auth = false) {
     - make composer_tests_update
     - .gitlab/wait-for-service-ready.sh
   script:
+    # The Fabric proxy changes network failure semantics in integration tests.
+    - unset HTTP_PROXY HTTPS_PROXY http_proxy https_proxy ALL_PROXY all_proxy
     - DD_TRACE_AGENT_TIMEOUT=1000 make $MAKE_TARGET RUST_DEBUG_BUILD=1 PHPUNIT_JUNIT="artifacts/tests/results.xml" <?= ASSERT_NO_MEMLEAKS ?>
 <?php after_script(".", true); ?>
     - find tests -type f \( -name 'phpunit_error.log' -o -name 'nginx_*.log' -o -name 'apache_*.log' -o -name 'php_fpm_*.log' -o -name 'dd_php_error.log' \) -exec cp --parents '{}' artifacts \;

.gitlab/run_php_language_tests.sh

@@ -1,6 +1,9 @@
 #!/usr/bin/env bash
 set -eo pipefail
 
+# The Fabric proxy changes network failure semantics and leaks HTTP_PROXY into $_SERVER.
+unset HTTP_PROXY HTTPS_PROXY http_proxy https_proxy ALL_PROXY all_proxy
+
 # Helper to parse version strings for comparison
 function version { echo "$@" | awk -F. '{ printf("%d%03d%03d%03d\n", $1,$2,$3,$4); }'; }
 

appsec/cmake/run-tests-wrapper.sh

@@ -68,6 +68,9 @@ else
   set -- "${@:1:$#-1}" "${EXTRA_FLAGS[@]}" "${!#}"
 fi
 
+# The Fabric proxy leaks HTTP_PROXY into $_SERVER as a request header.
+unset HTTP_PROXY HTTPS_PROXY http_proxy https_proxy ALL_PROXY all_proxy
+
 set -x
 exec "$@"