fix: required user agent header

.github/workflows/webserver.yml

@@ -37,9 +37,9 @@ jobs:
         uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
           path: /tmp/buildx-cache/
-          key: apache-ubuntu-20.04-${{ github.sha }}
+          key: apache-ubuntu-22.04-${{ github.sha }}
           restore-keys: |
-            apache-ubuntu-20.04
+            apache-ubuntu-22.04
       - name: setup docker image
         run: |
           cd instrumentation/otel-webserver-module
@@ -60,6 +60,12 @@ jobs:
             cp -r /build-dependencies /otel-webserver-module/;     \
 
             ./gradlew assembleWebServerModule -DtargetSystem=ubuntu'
+
+      - name: unit test
+        run: |
+          docker exec --workdir /otel-webserver-module apache_ubuntu_container \
+            ./gradlew runTests -DtargetSystem=ubuntu
+
       - name: update cache
         run: |
           rm -rf /tmp/buildx-cache/apache_ubuntu
@@ -107,8 +113,8 @@ jobs:
             ./gradlew assembleWebServerModule'
       - name: unit test
         run: |
-          docker exec apache_centos7_container bash -c \
-            'cd /otel-webserver-module; ./gradlew runUnitTest'
+          docker exec --workdir /otel-webserver-module apache_centos7_container \
+            ./gradlew runTests
       # - name: update cache
       #   run: |
       #     rm -rf /tmp/buildx-cache/apache_centos7
@@ -177,8 +183,8 @@ jobs:
             ./gradlew assembleWebServerModule'
       - name: unit test
         run: |
-          docker exec apache_almalinux8_container bash -c \
-            'cd /otel-webserver-module; ./gradlew runUnitTest'
+          docker exec --workdir /otel-webserver-module apache_almalinux8_container \
+            ./gradlew runTests
       # - name: update cache
       #   run: |
       #     rm -rf /tmp/buildx-cache/apache_almalinux8
@@ -206,7 +212,6 @@ jobs:
       #     ./gradlew :test:integration:integrationTests -i
       #     curl http://localhost:9411/api/v2/spans?serviceName=demoservice
 
-
   Codeql-build:
     permissions:
       security-events: write # for github/codeql-action/analyze to upload SARIF results
@@ -235,4 +240,3 @@ jobs:
           ./gradlew assembleWebserverModule -DtargetSystem=ubuntu --info
       - name: Perform CodeQL Analysis
         uses: github/codeql-action/analyze@db488ddef3bf6cb639b32c2e9a7c0a7ea8271d28 # v4.37.8
-

instrumentation/otel-webserver-module/build.gradle

@@ -539,6 +539,25 @@ task runApacheServer(type: Exec) {
     commandLine './ApacheTesting.sh', "${target_system}"
 }
 
+task runNginxIssue474Test(type: Exec) {
+    group = 'verification'
+    description = 'Run the NGINX issue #474 User-Agent regression test'
+
+    dependsOn assembleNginxModule
+
+    workingDir 'test/nginx'
+    commandLine './issue_474_user_agent_regression_test.sh',
+        "${buildDir}/opentelemetry-webserver-sdk-${osArch}-${osName}.tgz",
+        '1.26.0'
+}
+
+task runTests {
+    group = 'verification'
+    description = 'Run all webserver module tests'
+
+    dependsOn runUnitTest, runNginxIssue474Test
+}
+
 // Code Coverage
 
 task lcovCapture(type: Exec) {

instrumentation/otel-webserver-module/docker/almalinux8/Dockerfile

@@ -144,14 +144,14 @@ RUN wget --no-check-certificate https://ftp.gnu.org/gnu/automake/automake-${AUTO
     && cd .. && rm -rf automake-${AUTOMAKE_VERSION}.tar.gz
 
 # install libtool
-RUN wget --no-check-certificate https://ftpmirror.gnu.org/libtool/libtool-${LIBTOOL_VERSION}.tar.gz \
+RUN wget --no-check-certificate https://ftp.gnu.org/gnu/libtool/libtool-${LIBTOOL_VERSION}.tar.gz \
     && tar xzf libtool-${LIBTOOL_VERSION}.tar.gz \
     && cd libtool-${LIBTOOL_VERSION} \
     && ./configure --prefix=/usr \
     && make -j 6 \
     && make install \
     && libtool --version \
-    && cd .. && rm -rf libtool--${LIBTOOL_VERSION}.tar.gz
+    && cd .. && rm -rf libtool-${LIBTOOL_VERSION}.tar.gz
 
 #install log4cxx
 RUN mkdir -p dependencies/apache-log4cxx/${LOG4CXX_VERSION} \
@@ -254,9 +254,9 @@ RUN cd /otel-webserver-module/build \
 
 
 RUN cp /otel-webserver-module/conf/nginx/opentelemetry_module.conf /opt/ \
-    && sed -i '8i load_module /opt/opentelemetry-webserver-sdk/WebServerModule/Nginx/1.26.2/ngx_http_opentelemetry_module.so;' /etc/nginx/nginx.conf \
+    && sed -i "8i load_module /opt/opentelemetry-webserver-sdk/WebServerModule/Nginx/${NGINX_VERSION}/ngx_http_opentelemetry_module.so;" /etc/nginx/nginx.conf \
     && sed -i '33i include /opt/opentelemetry_module.conf;' /etc/nginx/nginx.conf \ 
     && cd /
 
 COPY entrypoint.sh /usr/local/bin/
-ENTRYPOINT ["entrypoint.sh"]
+ENTRYPOINT ["entrypoint.sh"]

instrumentation/otel-webserver-module/docker/centos7/Dockerfile

@@ -185,14 +185,14 @@ RUN wget --no-check-certificate https://ftp.gnu.org/gnu/automake/automake-${AUTO
     && cd .. && rm -rf automake-${AUTOMAKE_VERSION}.tar.gz
 
 # install libtool
-RUN wget --no-check-certificate https://ftpmirror.gnu.org/libtool/libtool-${LIBTOOL_VERSION}.tar.gz \
+RUN wget --no-check-certificate https://ftp.gnu.org/gnu/libtool/libtool-${LIBTOOL_VERSION}.tar.gz \
     && tar xzf libtool-${LIBTOOL_VERSION}.tar.gz \
     && cd libtool-${LIBTOOL_VERSION} \
     && ./configure --prefix=/usr \
     && make -j 6 \
     && make install \
     && libtool --version \
-    && cd .. && rm -rf libtool--${LIBTOOL_VERSION}.tar.gz
+    && cd .. && rm -rf libtool-${LIBTOOL_VERSION}.tar.gz
 
 #install log4cxx
 RUN mkdir -p dependencies/apache-log4cxx/${LOG4CXX_VERSION} \
@@ -303,4 +303,4 @@ RUN rm -rf grpc && rm -rf autoconf-${AUTOCONF_VERSION} && rm -rf automake-${AUTO
     && rm -f httpd-2.2.31.tar.gz && rm -f httpd-2.4.23.tar.gz
 
 COPY entrypoint.sh /usr/local/bin/
-ENTRYPOINT ["entrypoint.sh"]
+ENTRYPOINT ["entrypoint.sh"]

instrumentation/otel-webserver-module/docker/ubuntu20.04/Dockerfile

@@ -190,7 +190,7 @@ RUN echo "deb [signed-by=/usr/share/keyrings/nginx-archive-keyring.gpg] \
     | tee /etc/apt/sources.list.d/nginx.list \
     && echo "Package: *\nPin: origin nginx.org\nPin: release o=nginx\nPin-Priority: 900\n" \
     | tee /etc/apt/preferences.d/99nginx \
-    && apt update -y && apt install nginx -y
+    && apt update -y && apt install "nginx=${NGINX_VERSION}-1~focal" -y
 
 # Build Webserver Module
 COPY . /otel-webserver-module

instrumentation/otel-webserver-module/src/nginx/ngx_http_opentelemetry_module.c

@@ -2056,10 +2056,14 @@ static void fillRequestPayload(request_payload* req_payload, ngx_http_request_t*
     temp_request_method[(r->method_name).len]='\0';
     req_payload->request_method = temp_request_method;
 
-    char *temp_user_agent = ngx_pcalloc(r->pool, r->headers_in.user_agent->value.len +1);
-    strcpy(temp_user_agent,(const char*)(r->headers_in.user_agent->value.data));
-    temp_user_agent[r->headers_in.user_agent->value.len]='\0';
-    req_payload->user_agent = temp_user_agent;
+    ngx_table_elt_t *user_agent = r->headers_in.user_agent;
+    if (user_agent == NULL) {
+        req_payload->user_agent = "";
+    } else {
+        char *temp_user_agent = ngx_pcalloc(r->pool, user_agent->value.len + 1);
+        ngx_memcpy(temp_user_agent, user_agent->value.data, user_agent->value.len);
+        req_payload->user_agent = temp_user_agent;
+    }
 
     ngx_uint_t remote_port = 0;
     if (r->connection != NULL) {

instrumentation/otel-webserver-module/test/nginx/issue_474_user_agent_regression_test.sh

@@ -0,0 +1,221 @@
+#!/usr/bin/env bash
+
+set -Eeuo pipefail
+
+if [[ $# -ne 2 ]]; then
+    echo "Usage: $0 <webserver-module-archive> <nginx-version>" >&2
+    exit 2
+fi
+
+archive_path="$1"
+nginx_version="$2"
+nginx_binary="${NGINX_BINARY:-nginx}"
+test_port="${NGINX_ISSUE_474_TEST_PORT:-18080}"
+
+for command in curl ps tar "$nginx_binary"; do
+    if ! command -v "$command" >/dev/null 2>&1; then
+        echo "Required command not found: $command" >&2
+        exit 1
+    fi
+done
+
+if [[ ! -f "$archive_path" ]]; then
+    echo "Webserver module archive not found: $archive_path" >&2
+    exit 1
+fi
+
+runtime_version="$($nginx_binary -v 2>&1)"
+if [[ "$runtime_version" != *"nginx/$nginx_version"* ]]; then
+    echo "Expected nginx/$nginx_version, but found: $runtime_version" >&2
+    exit 1
+fi
+
+test_root="$(mktemp -d /tmp/otel-nginx-issue-474.XXXXXX)"
+nginx_prefix="$test_root/nginx"
+nginx_config="$nginx_prefix/nginx.conf"
+nginx_error_log="$nginx_prefix/error.log"
+nginx_pid_file="$nginx_prefix/nginx.pid"
+nginx_pid=""
+current_test="startup"
+
+cleanup() {
+    local exit_code=$?
+    trap - EXIT
+
+    if [[ -n "$nginx_pid" ]] && kill -0 "$nginx_pid" >/dev/null 2>&1; then
+        "$nginx_binary" -p "$nginx_prefix/" -c "$nginx_config" -s quit >/dev/null 2>&1 || true
+        for _ in {1..50}; do
+            if ! kill -0 "$nginx_pid" >/dev/null 2>&1; then
+                break
+            fi
+            sleep 0.1
+        done
+        if kill -0 "$nginx_pid" >/dev/null 2>&1; then
+            kill "$nginx_pid" >/dev/null 2>&1 || true
+        fi
+    fi
+
+    if [[ $exit_code -ne 0 ]]; then
+        echo "FAILED: $current_test" >&2
+        if [[ -f "$nginx_error_log" ]]; then
+            echo "NGINX error log:" >&2
+            cat "$nginx_error_log" >&2
+        fi
+    fi
+
+    case "$test_root" in
+        /tmp/otel-nginx-issue-474.*)
+            rm -rf -- "$test_root"
+            ;;
+    esac
+
+    exit "$exit_code"
+}
+trap cleanup EXIT
+
+mkdir -p "$nginx_prefix"
+tar -xzf "$archive_path" -C "$test_root"
+
+sdk_root="$test_root/opentelemetry-webserver-sdk"
+module_path="$sdk_root/WebServerModule/Nginx/$nginx_version/ngx_http_opentelemetry_module.so"
+sdk_library_path="$sdk_root/sdk_lib/lib"
+
+if [[ ! -f "$module_path" ]]; then
+    echo "NGINX module not found in archive: $module_path" >&2
+    exit 1
+fi
+
+if [[ ! -x "$sdk_root/install.sh" ]]; then
+    echo "SDK installer not found in archive: $sdk_root/install.sh" >&2
+    exit 1
+fi
+
+"$sdk_root/install.sh" --ignore-permissions
+
+export LD_LIBRARY_PATH="$sdk_library_path${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
+export OTEL_SDK_LOG_CONFIG_PATH="$sdk_root/conf/opentelemetry_sdk_log4cxx.xml"
+
+cat >"$nginx_config" <<EOF
+load_module $module_path;
+
+user root;
+worker_processes 1;
+pid $nginx_pid_file;
+error_log $nginx_error_log notice;
+
+events {
+    worker_connections 64;
+}
+
+http {
+    access_log off;
+
+    NginxModuleEnabled ON;
+    NginxModuleOtelSpanExporter osstream;
+    NginxModuleOtelSpanProcessor simple;
+    NginxModuleOtelSampler always_on;
+    NginxModuleServiceName issue-474;
+    NginxModuleServiceNamespace regression-test;
+    NginxModuleServiceInstanceId ci;
+    NginxModuleResolveBackends OFF;
+    NginxModuleTraceAsError OFF;
+
+    server {
+        listen 127.0.0.1:$test_port;
+        server_name localhost;
+
+        location = /issue-474 {
+            return 200 "ok\n";
+        }
+    }
+}
+EOF
+
+"$nginx_binary" -t -p "$nginx_prefix/" -c "$nginx_config"
+"$nginx_binary" -p "$nginx_prefix/" -c "$nginx_config"
+
+for _ in {1..50}; do
+    if [[ -s "$nginx_pid_file" ]]; then
+        nginx_pid="$(<"$nginx_pid_file")"
+        if curl --silent --fail --max-time 1 --http1.1 \
+            -H 'User-Agent: issue-474-readiness-check' \
+            "http://127.0.0.1:$test_port/issue-474" >/dev/null; then
+            break
+        fi
+    fi
+    sleep 0.1
+done
+
+if [[ -z "$nginx_pid" ]] || ! kill -0 "$nginx_pid" >/dev/null 2>&1; then
+    echo "NGINX did not start" >&2
+    exit 1
+fi
+
+worker_pid() {
+    ps -eo pid=,ppid= | awk -v parent="$nginx_pid" '$2 == parent { print $1; exit }'
+}
+
+assert_no_worker_crash() {
+    if grep -Eiq 'worker process .*exited on signal|segmentation fault|core dumped' "$nginx_error_log"; then
+        echo "NGINX worker crash detected" >&2
+        return 1
+    fi
+}
+
+run_test_case() {
+    local test_name="$1"
+    shift
+
+    current_test="$test_name"
+    echo "RUN: $test_name"
+
+    local worker_before
+    local worker_after
+    local http_status
+
+    worker_before="$(worker_pid)"
+    if [[ -z "$worker_before" ]]; then
+        echo "Unable to find the NGINX worker before $test_name" >&2
+        return 1
+    fi
+
+    if ! http_status="$(curl --silent --show-error --output /dev/null \
+        --write-out '%{http_code}' --max-time 5 --http1.1 \
+        "$@" "http://127.0.0.1:$test_port/issue-474")"; then
+        echo "Request failed for $test_name" >&2
+        return 1
+    fi
+
+    if [[ "$http_status" != "200" ]]; then
+        echo "Expected HTTP 200 for $test_name, received $http_status" >&2
+        return 1
+    fi
+
+    worker_after="$(worker_pid)"
+    if [[ "$worker_after" != "$worker_before" ]]; then
+        echo "NGINX worker changed during $test_name: $worker_before -> ${worker_after:-missing}" >&2
+        return 1
+    fi
+
+    assert_no_worker_crash
+    echo "PASS: $test_name"
+}
+
+test_non_empty_user_agent() {
+    run_test_case "non-empty User-Agent" -H 'User-Agent: otel-regression-test'
+}
+
+test_omitted_user_agent() {
+    run_test_case "omitted User-Agent" -H 'User-Agent:'
+}
+
+test_empty_user_agent() {
+    run_test_case "empty User-Agent" -H 'User-Agent;'
+}
+
+test_non_empty_user_agent
+test_omitted_user_agent
+test_empty_user_agent
+
+current_test="complete"
+echo "All NGINX issue #474 regression tests passed"