diff --git a/examples/baggage/README.md b/examples/baggage/README.md new file mode 100644 index 00000000..4c20d8f1 --- /dev/null +++ b/examples/baggage/README.md @@ -0,0 +1,60 @@ +# Baggage examples + +This is an elementary application providing an end-to-end example usage of [OpenTelemetry baggage](https://opentelemetry.io/docs/concepts/signals/baggage/). + +It is split in two services: a gateway and a backend +- an HTTP backend service running on http://localhost:9000/backend/ +- an HTTP gateway service running on http://localhost:8000/gateway/ + +The gateway is in charge of authentication and delegates to the backend by providing a technical ID for the backend to use for authentication. + +## Build + +```bash +./gradlew clean assemble +``` + +## Configure + +The javaagent is already packaged and included in the application by using [runtime attach](https://www.elastic.co/docs/reference/opentelemetry/edot-sdks/java/setup/runtime-attach) feature. + +OTel configuration must be provided through environment variables or JVM system properties. + +## Run + +Backend: +```shell +export OTEL_SERVICE_NAME='backend' +java \ +-Dotel.java.experimental.span-attributes.copy-from-baggage.include=example.customer.id,example.customer.name \ +-Dotel.java.experimental.log-attributes.copy-from-baggage.include=example.customer.id,example.customer.name \ +-jar ./build/libs/baggage-example-all.jar backend +``` + +Gateway: +```shell +export OTEL_SERVICE_NAME='gateway' +java \ +-Dotel.java.experimental.span-attributes.copy-from-baggage.include=example.customer.id,example.customer.name \ +-Dotel.java.experimental.log-attributes.copy-from-baggage.include=example.customer.id,example.customer.name \ +-jar ./build/libs/baggage-example-all.jar gateway +``` + +Once both services are started, you can execute queries on the gateway with queries like the following: +```shell +curl -H 'Authorization: secret=12345' http://localhost:8000/gateway/ +``` + +This will create the following log messages on `gateway` and `backend` respectively: +``` +gateway request for customer ID = 12345 +backend request for customer ID = 12345 +``` + +All the spans and logs captured within the scope of the baggage will have the following attributes: +- `example.customer.name` with value `my-awesome-customer-12345` +- `example.customer.id` with value `12345` + +As a result, it is now possible to use those custom attributes to filter data and create +dedicated dashboards. The only code modification required is in the gateway code. + diff --git a/examples/baggage/build.gradle.kts b/examples/baggage/build.gradle.kts new file mode 100644 index 00000000..dc78c9ae --- /dev/null +++ b/examples/baggage/build.gradle.kts @@ -0,0 +1,44 @@ +plugins { + application + java + + id("com.gradleup.shadow") version "8.3.5" +} + +group = "baggage.example" +version = "1.0-SNAPSHOT" + +repositories { + mavenCentral() +} + +dependencies { + implementation("co.elastic.otel:elastic-otel-runtime-attach:1.4.1") + implementation(platform("org.slf4j:slf4j-bom:2.0.16")) + + // using a "real" logger backend as slf4j-simple just uses stdout/stderr + // and is not instrumented for log capture by otel instrumentation + implementation("org.apache.logging.log4j:log4j-slf4j2-impl:2.25.0") + + // otel API to access Baggage API + implementation("io.opentelemetry:opentelemetry-api:1.51.0") + +} + +application { + mainClass = "baggage.example.Main" +} + +tasks { + compileJava { + options.release.set(21) + } + + shadowJar { + archiveFileName.set("baggage-example-all.jar") + } + + assemble { + dependsOn("shadowJar") + } +} diff --git a/examples/baggage/gradle/wrapper/gradle-wrapper.jar b/examples/baggage/gradle/wrapper/gradle-wrapper.jar new file mode 100644 index 00000000..9bbc975c Binary files /dev/null and b/examples/baggage/gradle/wrapper/gradle-wrapper.jar differ diff --git a/examples/baggage/gradle/wrapper/gradle-wrapper.properties b/examples/baggage/gradle/wrapper/gradle-wrapper.properties new file mode 100644 index 00000000..36e4933e --- /dev/null +++ b/examples/baggage/gradle/wrapper/gradle-wrapper.properties @@ -0,0 +1,8 @@ +distributionBase=GRADLE_USER_HOME +distributionPath=wrapper/dists +distributionSha256Sum=20f1b1176237254a6fc204d8434196fa11a4cfb387567519c61556e8710aed78 +distributionUrl=https\://services.gradle.org/distributions/gradle-8.13-bin.zip +networkTimeout=10000 +validateDistributionUrl=true +zipStoreBase=GRADLE_USER_HOME +zipStorePath=wrapper/dists diff --git a/examples/baggage/gradlew b/examples/baggage/gradlew new file mode 100755 index 00000000..b740cf13 --- /dev/null +++ b/examples/baggage/gradlew @@ -0,0 +1,249 @@ +#!/bin/sh + +# +# Copyright © 2015-2021 the original authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# https://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# + +############################################################################## +# +# Gradle start up script for POSIX generated by Gradle. +# +# Important for running: +# +# (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is +# noncompliant, but you have some other compliant shell such as ksh or +# bash, then to run this script, type that shell name before the whole +# command line, like: +# +# ksh Gradle +# +# Busybox and similar reduced shells will NOT work, because this script +# requires all of these POSIX shell features: +# * functions; +# * expansions «$var», «${var}», «${var:-default}», «${var+SET}», +# «${var#prefix}», «${var%suffix}», and «$( cmd )»; +# * compound commands having a testable exit status, especially «case»; +# * various built-in commands including «command», «set», and «ulimit». +# +# Important for patching: +# +# (2) This script targets any POSIX shell, so it avoids extensions provided +# by Bash, Ksh, etc; in particular arrays are avoided. +# +# The "traditional" practice of packing multiple parameters into a +# space-separated string is a well documented source of bugs and security +# problems, so this is (mostly) avoided, by progressively accumulating +# options in "$@", and eventually passing that to Java. +# +# Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS, +# and GRADLE_OPTS) rely on word-splitting, this is performed explicitly; +# see the in-line comments for details. +# +# There are tweaks for specific operating systems such as AIX, CygWin, +# Darwin, MinGW, and NonStop. +# +# (3) This script is generated from the Groovy template +# https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt +# within the Gradle project. +# +# You can find Gradle at https://github.com/gradle/gradle/. +# +############################################################################## + +# Attempt to set APP_HOME + +# Resolve links: $0 may be a link +app_path=$0 + +# Need this for daisy-chained symlinks. +while + APP_HOME=${app_path%"${app_path##*/}"} # leaves a trailing /; empty if no leading path + [ -h "$app_path" ] +do + ls=$( ls -ld "$app_path" ) + link=${ls#*' -> '} + case $link in #( + /*) app_path=$link ;; #( + *) app_path=$APP_HOME$link ;; + esac +done + +# This is normally unused +# shellcheck disable=SC2034 +APP_BASE_NAME=${0##*/} +# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036) +APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit + +# Use the maximum available, or set MAX_FD != -1 to use that value. +MAX_FD=maximum + +warn () { + echo "$*" +} >&2 + +die () { + echo + echo "$*" + echo + exit 1 +} >&2 + +# OS specific support (must be 'true' or 'false'). +cygwin=false +msys=false +darwin=false +nonstop=false +case "$( uname )" in #( + CYGWIN* ) cygwin=true ;; #( + Darwin* ) darwin=true ;; #( + MSYS* | MINGW* ) msys=true ;; #( + NONSTOP* ) nonstop=true ;; +esac + +CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar + + +# Determine the Java command to use to start the JVM. +if [ -n "$JAVA_HOME" ] ; then + if [ -x "$JAVA_HOME/jre/sh/java" ] ; then + # IBM's JDK on AIX uses strange locations for the executables + JAVACMD=$JAVA_HOME/jre/sh/java + else + JAVACMD=$JAVA_HOME/bin/java + fi + if [ ! -x "$JAVACMD" ] ; then + die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." + fi +else + JAVACMD=java + if ! command -v java >/dev/null 2>&1 + then + die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." + fi +fi + +# Increase the maximum file descriptors if we can. +if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then + case $MAX_FD in #( + max*) + # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked. + # shellcheck disable=SC2039,SC3045 + MAX_FD=$( ulimit -H -n ) || + warn "Could not query maximum file descriptor limit" + esac + case $MAX_FD in #( + '' | soft) :;; #( + *) + # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked. + # shellcheck disable=SC2039,SC3045 + ulimit -n "$MAX_FD" || + warn "Could not set maximum file descriptor limit to $MAX_FD" + esac +fi + +# Collect all arguments for the java command, stacking in reverse order: +# * args from the command line +# * the main class name +# * -classpath +# * -D...appname settings +# * --module-path (only if needed) +# * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables. + +# For Cygwin or MSYS, switch paths to Windows format before running java +if "$cygwin" || "$msys" ; then + APP_HOME=$( cygpath --path --mixed "$APP_HOME" ) + CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" ) + + JAVACMD=$( cygpath --unix "$JAVACMD" ) + + # Now convert the arguments - kludge to limit ourselves to /bin/sh + for arg do + if + case $arg in #( + -*) false ;; # don't mess with options #( + /?*) t=${arg#/} t=/${t%%/*} # looks like a POSIX filepath + [ -e "$t" ] ;; #( + *) false ;; + esac + then + arg=$( cygpath --path --ignore --mixed "$arg" ) + fi + # Roll the args list around exactly as many times as the number of + # args, so each arg winds up back in the position where it started, but + # possibly modified. + # + # NB: a `for` loop captures its iteration list before it begins, so + # changing the positional parameters here affects neither the number of + # iterations, nor the values presented in `arg`. + shift # remove old arg + set -- "$@" "$arg" # push replacement arg + done +fi + + +# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"' + +# Collect all arguments for the java command: +# * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments, +# and any embedded shellness will be escaped. +# * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be +# treated as '${Hostname}' itself on the command line. + +set -- \ + "-Dorg.gradle.appname=$APP_BASE_NAME" \ + -classpath "$CLASSPATH" \ + org.gradle.wrapper.GradleWrapperMain \ + "$@" + +# Stop when "xargs" is not available. +if ! command -v xargs >/dev/null 2>&1 +then + die "xargs is not available" +fi + +# Use "xargs" to parse quoted args. +# +# With -n1 it outputs one arg per line, with the quotes and backslashes removed. +# +# In Bash we could simply go: +# +# readarray ARGS < <( xargs -n1 <<<"$var" ) && +# set -- "${ARGS[@]}" "$@" +# +# but POSIX shell has neither arrays nor command substitution, so instead we +# post-process each arg (as a line of input to sed) to backslash-escape any +# character that might be a shell metacharacter, then use eval to reverse +# that process (while maintaining the separation between arguments), and wrap +# the whole thing up as a single "set" statement. +# +# This will of course break if any of these variables contains a newline or +# an unmatched quote. +# + +eval "set -- $( + printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" | + xargs -n1 | + sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' | + tr '\n' ' ' + )" '"$@"' + +exec "$JAVACMD" "$@" diff --git a/examples/baggage/gradlew.bat b/examples/baggage/gradlew.bat new file mode 100644 index 00000000..7101f8e4 --- /dev/null +++ b/examples/baggage/gradlew.bat @@ -0,0 +1,92 @@ +@rem +@rem Copyright 2015 the original author or authors. +@rem +@rem Licensed under the Apache License, Version 2.0 (the "License"); +@rem you may not use this file except in compliance with the License. +@rem You may obtain a copy of the License at +@rem +@rem https://www.apache.org/licenses/LICENSE-2.0 +@rem +@rem Unless required by applicable law or agreed to in writing, software +@rem distributed under the License is distributed on an "AS IS" BASIS, +@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +@rem See the License for the specific language governing permissions and +@rem limitations under the License. +@rem + +@if "%DEBUG%"=="" @echo off +@rem ########################################################################## +@rem +@rem Gradle startup script for Windows +@rem +@rem ########################################################################## + +@rem Set local scope for the variables with windows NT shell +if "%OS%"=="Windows_NT" setlocal + +set DIRNAME=%~dp0 +if "%DIRNAME%"=="" set DIRNAME=. +@rem This is normally unused +set APP_BASE_NAME=%~n0 +set APP_HOME=%DIRNAME% + +@rem Resolve any "." and ".." in APP_HOME to make it shorter. +for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi + +@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m" + +@rem Find java.exe +if defined JAVA_HOME goto findJavaFromJavaHome + +set JAVA_EXE=java.exe +%JAVA_EXE% -version >NUL 2>&1 +if %ERRORLEVEL% equ 0 goto execute + +echo. 1>&2 +echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2 +echo. 1>&2 +echo Please set the JAVA_HOME variable in your environment to match the 1>&2 +echo location of your Java installation. 1>&2 + +goto fail + +:findJavaFromJavaHome +set JAVA_HOME=%JAVA_HOME:"=% +set JAVA_EXE=%JAVA_HOME%/bin/java.exe + +if exist "%JAVA_EXE%" goto execute + +echo. 1>&2 +echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2 +echo. 1>&2 +echo Please set the JAVA_HOME variable in your environment to match the 1>&2 +echo location of your Java installation. 1>&2 + +goto fail + +:execute +@rem Setup the command line + +set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar + + +@rem Execute Gradle +"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %* + +:end +@rem End local scope for the variables with windows NT shell +if %ERRORLEVEL% equ 0 goto mainEnd + +:fail +rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of +rem the _cmd.exe /c_ return code! +set EXIT_CODE=%ERRORLEVEL% +if %EXIT_CODE% equ 0 set EXIT_CODE=1 +if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE% +exit /b %EXIT_CODE% + +:mainEnd +if "%OS%"=="Windows_NT" endlocal + +:omega diff --git a/examples/baggage/settings.gradle.kts b/examples/baggage/settings.gradle.kts new file mode 100644 index 00000000..72a4ff0f --- /dev/null +++ b/examples/baggage/settings.gradle.kts @@ -0,0 +1,2 @@ +rootProject.name = "baggage-example" + diff --git a/examples/baggage/src/main/java/baggage/example/Main.java b/examples/baggage/src/main/java/baggage/example/Main.java new file mode 100644 index 00000000..8f100f4d --- /dev/null +++ b/examples/baggage/src/main/java/baggage/example/Main.java @@ -0,0 +1,33 @@ +package baggage.example; + +import co.elastic.otel.agent.attach.RuntimeAttach; + +public class Main { + public static void main(String[] args) throws Exception { + + RuntimeAttach.attachJavaagentToCurrentJvm(); + + String arg = args.length > 0 ? args[0] : null; + if (arg == null) { + throw new RuntimeException("missing argument: 'backend' or 'gateway' expected"); + } + + SimpleServer server; + switch (arg) { + case "backend": + server = SimpleServer.createBackend(); + break; + case "gateway": + server = SimpleServer.createGateway(); + break; + default: + throw new RuntimeException("unsupported argument value: " + arg); + } + + Runtime.getRuntime().addShutdownHook(new Thread(server::stop)); + System.out.printf("%s server started on url %s, hit ctrl-c to terminate%n", arg, server.getUrl()); + server.start(); + + + } +} diff --git a/examples/baggage/src/main/java/baggage/example/SimpleServer.java b/examples/baggage/src/main/java/baggage/example/SimpleServer.java new file mode 100644 index 00000000..9d3c51a7 --- /dev/null +++ b/examples/baggage/src/main/java/baggage/example/SimpleServer.java @@ -0,0 +1,135 @@ +package baggage.example; + +import com.sun.net.httpserver.HttpExchange; +import com.sun.net.httpserver.HttpHandler; +import com.sun.net.httpserver.HttpServer; +import io.opentelemetry.api.baggage.Baggage; +import io.opentelemetry.context.Context; +import io.opentelemetry.context.Scope; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import java.io.IOException; +import java.io.OutputStream; +import java.net.InetSocketAddress; +import java.net.URI; +import java.net.http.HttpClient; +import java.net.http.HttpRequest; +import java.net.http.HttpResponse; +import java.util.concurrent.Executors; + +public class SimpleServer { + + private static final Logger log = LoggerFactory.getLogger(SimpleServer.class); + private final HttpServer server; + private final String url; + + private SimpleServer(HttpServer server, String url) { + this.server = server; + this.url = url; + } + + private static SimpleServer create(int port, String path, HttpHandler handler) + throws IOException { + HttpServer server = HttpServer.create(new InetSocketAddress(port), 0); + server.createContext(path, handler); + server.setExecutor(Executors.newCachedThreadPool()); + return new SimpleServer(server, String.format("http://localhost:%d%s", port, path)); + } + + public static SimpleServer createBackend() throws IOException { + return create(9000, "/backend/", exchange -> { + + // Authentication is assumed to be implemented by the gateway and backend trusts its HTTP header + // the backend only needs to have a technical ID for customer. + String customerId = exchange.getRequestHeaders().getFirst("customer_id"); + + // Baggage is automatically propagated to the backend, and we can access it through API. + // It is not required to modify backend code as it is possible to configure the instrumentation + // to automatically propagate some baggage entries to span/log attributes through configuration. + // + // To enable this, configure the backend with the following JVM arguments: + // -Dotel.java.experimental.span-attributes.copy-from-baggage.include=example.customer.id,example.customer.name + // -Dotel.java.experimental.log-attributes.copy-from-baggage.include=example.customer.id,example.customer.name + + // This log statement in the backend should only have access to the customer ID. + // The log even captured will include the baggage entries, which include both ID and name. + log.atInfo().setMessage("backend request for customer ID = " + customerId).log(); + + String response = String.format("hello from backend, customer_id=%s\n", customerId); + stringResponse(exchange, 200, response); + }); + } + + public static SimpleServer createGateway() throws IOException { + + HttpClient client = HttpClient.newHttpClient(); + return create(8000, "/gateway/", exchange -> { + + // emulate authentication from header, don't do this in production + String secretPrefix = "secret="; + String customerAuth = exchange.getRequestHeaders().getFirst("Authorization"); + String customerId = null; + if (customerAuth.startsWith(secretPrefix)) { + customerId = customerAuth.substring(secretPrefix.length()); + } + if (customerId == null) { + stringResponse(exchange, 401, "auth error"); + return; + } + + HttpRequest request = HttpRequest.newBuilder() + .uri(URI.create("http://localhost:9000/backend/")) + .header("customer_id", customerId) + .build(); + + // add new entries to current baggage + Baggage baggage = Baggage.current().toBuilder() + .put("example.customer.id", customerId) + .put("example.customer.name", String.format("my-awesome-customer-%s", customerId)) + .build(); + // create a new context with the updated baggage and make it current for the backend HTTP call + Context contextWithBaggage = baggage.storeInContext(Context.current()); + try (Scope scope = contextWithBaggage.makeCurrent()) { + + // All the log statements and spans created with the baggage-enabled context + // will have the baggage entries added as span/log attributes when configured to do so. + // + // Doing so allows to "annotate" everything that relatest to the given customer in the monitoring + // backend with minor code modifications. + // + // To enable this, configure the gateway with the following JVM arguments: + // -Dotel.java.experimental.span-attributes.copy-from-baggage.include=example.customer.id,example.customer.name + // -Dotel.java.experimental.log-attributes.copy-from-baggage.include=example.customer.id,example.customer.name + log.atInfo().setMessage("gateway request for customer ID = " + customerId).log(); + + // call backend and forward its response + HttpResponse response; + try { + response = client.send(request, HttpResponse.BodyHandlers.ofString()); + } catch (InterruptedException e) { + stringResponse(exchange, 500, "internal error"); + return; + } + stringResponse(exchange, 200, response.body()); + } + }); + } + + private static void stringResponse(HttpExchange exchange, int statusCode, String response) + throws IOException { + exchange.sendResponseHeaders(statusCode, response.length()); + OutputStream os = exchange.getResponseBody(); + os.write(response.getBytes()); + os.close(); + } + + public String getUrl() {return this.url;} + + public void start() { + server.start(); + } + + public void stop() { + server.stop(1); + } +} diff --git a/examples/baggage/src/main/resources/log4j2.xml b/examples/baggage/src/main/resources/log4j2.xml new file mode 100644 index 00000000..ab8a49fe --- /dev/null +++ b/examples/baggage/src/main/resources/log4j2.xml @@ -0,0 +1,13 @@ + + + + + + + + + + + + +