AWS XRay SDK无法读取docker容器中的环境变量

Question

AWS XRay是一种跟踪服务，允许您跟踪分布式系统中的请求，甚至对您的服务进行配置。XRay基本上监控您的服务，并通过UDP将每个请求的数据发送到服务的守护进程，该守护进程收集这些数据并将其发送到AWS。

当这个守护程序在本地或EC2中运行时，它是运行服务的机器的本地守护程序，并且在端口2000上可用。这是守护程序主机位置的默认配置。

当在Kubernetes中运行时，需要设置一个守护进程在每个节点上运行。根据使用Kubernetes设置XRay的文档，您可以通过使用所需主机设置环境变量AWS_XRAY_DAEMON_ADDRESS来覆盖默认值，也可以设置JVM系统变量com.amazonaws.xray.emitters.daemonAddress。SDK文档中也提到了这一点。

由于我的用例以及我们在组织中共享配置的方式，我希望使用设置环境变量的方法。

根据文件，我们通过我们的舵图将其部署：

env:
- name: AWS_XRAY_DAEMON_ADDRESS
value: aws-xray-daemon.default

通过执行服务运行的pod，并运行printenv，我们可以看到在部署时成功设置了该值。

---

问题：

当XRay尝试评测并向守护进程发送数据时，会抛出一个SdkClientException：

com.amazonaws.SdkClientException: Unable to execute HTTP request: Connect to 127.0.0.1:2000 [/127.0.0.1] failed: Connection refused (Connection refused)
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.handleRetryableException(AmazonHttpClient.java:1201) ~[aws-java-sdk-core-1.11.739.jar!/:na]
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1147) ~[aws-java-sdk-core-1.11.739.jar!/:na]
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:796) ~[aws-java-sdk-core-1.11.739.jar!/:na]
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:764) ~[aws-java-sdk-core-1.11.739.jar!/:na]
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:738) ~[aws-java-sdk-core-1.11.739.jar!/:na]
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.access$500(AmazonHttpClient.java:698) ~[aws-java-sdk-core-1.11.739.jar!/:na]
at com.amazonaws.http.AmazonHttpClient$RequestExecutionBuilderImpl.execute(AmazonHttpClient.java:680) ~[aws-java-sdk-core-1.11.739.jar!/:na]
at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:544) ~[aws-java-sdk-core-1.11.739.jar!/:na]
at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:524) ~[aws-java-sdk-core-1.11.739.jar!/:na]
at com.amazonaws.services.xray.AWSXRayClient.doInvoke(AWSXRayClient.java:1607) ~[aws-java-sdk-xray-1.11.739.jar!/:na]
at com.amazonaws.services.xray.AWSXRayClient.invoke(AWSXRayClient.java:1574) ~[aws-java-sdk-xray-1.11.739.jar!/:na]
at com.amazonaws.services.xray.AWSXRayClient.invoke(AWSXRayClient.java:1563) ~[aws-java-sdk-xray-1.11.739.jar!/:na]
at com.amazonaws.services.xray.AWSXRayClient.executeGetSamplingRules(AWSXRayClient.java:800) ~[aws-java-sdk-xray-1.11.739.jar!/:na]
at com.amazonaws.services.xray.AWSXRayClient.getSamplingRules(AWSXRayClient.java:771) ~[aws-java-sdk-xray-1.11.739.jar!/:na]
at com.amazonaws.xray.strategy.sampling.pollers.RulePoller.pollRule(RulePoller.java:65) ~[aws-xray-recorder-sdk-core-2.4.0.jar!/:na]
at com.amazonaws.xray.strategy.sampling.pollers.RulePoller.lambda$start$0(RulePoller.java:46) ~[aws-xray-recorder-sdk-core-2.4.0.jar!/:na]
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[na:na]
at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source) ~[na:na]
at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) ~[na:na]
at java.base/java.lang.Thread.run(Unknown Source) ~[na:na]
...

这意味着AWS SDK并没有像文档中所建议的那样获取这个环境变量，而只是使用默认值127.0.0.1:2000。

然后，我深入研究了SDK代码，以了解它是如何检索这个变量的，并发现运行它的代码使用System.getenv("AWS_XRAY_DAEMON_ADDRESS")，如下所示：

/**
* Environment variable key used to override the address to which UDP packets will be emitted. Valid values are of the form `ip_address:port`. Takes precedence over any system property,
* constructor value, or setter value used.
*/
public static final String DAEMON_ADDRESS_ENVIRONMENT_VARIABLE_KEY = "AWS_XRAY_DAEMON_ADDRESS";
/**
* System property key used to override the address to which UDP packets will be emitted. Valid values are of the form `ip_address:port`. Takes precedence over any constructor or setter value
* used.
*/
public static final String DAEMON_ADDRESS_SYSTEM_PROPERTY_KEY = "com.amazonaws.xray.emitters.daemonAddress";
public DaemonConfiguration() {
String environmentAddress = System.getenv(DAEMON_ADDRESS_ENVIRONMENT_VARIABLE_KEY);
String systemAddress = System.getProperty(DAEMON_ADDRESS_SYSTEM_PROPERTY_KEY);
if (setUDPAndTCPAddress(environmentAddress)) {
logger.info(String.format("Environment variable %s is set. Emitting to daemon on address %s.", DAEMON_ADDRESS_ENVIRONMENT_VARIABLE_KEY, getUDPAddress()));
} else if (setUDPAndTCPAddress(systemAddress)) {
logger.info(String.format("System property %s is set. Emitting to daemon on address %s.", DAEMON_ADDRESS_SYSTEM_PROPERTY_KEY, getUDPAddress()));
}
}

所以我想，也许我没有正确设置环境变量？因此，我添加了一个在服务启动时检索环境变量的日志，发现JVM确实可以找到值：

代码：

System.out.println("System.getenv("AWS_XRAY_DAEMON_ADDRESS")" + " = " + System.getenv("AWS_XRAY_DAEMON_ADDRESS")) 

输出：

System.getenv("AWS_XRAY_DAEMON_ADDRESS") = aws-xray-daemon.default

据我所知，这段代码与AWS SDK应该运行的代码完全匹配，但它似乎从未被执行过，如果是，它的结果与我用日志测试的结果不同。

在本地运行时，我无法复制这个问题，因为它会从本地环境变量中获取我提供的主机。我还确认，当使用断点在本地运行时，可以达到上面粘贴的AWS SDK代码。

有什么想法吗？

---

渐变代码段：

ext {
...
springCloudVersion = "Greenwich.RELEASE"
awsCoreVersion = '1.11.739'
awsXrayVersion = '2.4.0' 
...
}
dependencyManagement {
imports {
mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
mavenBom "com.amazonaws:aws-java-sdk-bom:${awsCoreVersion}"
mavenBom "com.amazonaws:aws-xray-recorder-sdk-bom:${awsXrayVersion}"
}
}
dependencies {
...
implementation "com.amazonaws:aws-java-sdk-core"
implementation "com.amazonaws:aws-xray-recorder-sdk-core" 
implementation "com.amazonaws:aws-xray-recorder-sdk-aws-sdk" 
implementation "com.amazonaws:aws-xray-recorder-sdk-spring" 
implementation "com.amazonaws:aws-xray-recorder-sdk-apache-http" 
implementation "com.amazonaws:aws-xray-recorder-sdk-sql-postgres" 
implementation 'org.springframework.boot:spring-boot-starter-web'
implementation 'org.springframework.boot:spring-boot-starter'
implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
implementation 'org.springframework.boot:spring-boot-starter-security'
...
}

其他信息：

• 在Spring Boot v2.2.1中运行
• OpenJDK v11.0.4
• Gradle v6.0.1

其他尝试：-我尝试通过Dockerfile设置环境变量。结果是一样的。

Answer 1

事实证明，我链接的博客文章不是一篇好的博客文章。在这个例子中，他们没有指定主机的端口：

env:
- name: AWS_XRAY_DAEMON_ADDRESS 
value: xray-service.default

更改环境变量以包括端口修复了问题：

env:
- name: AWS_XRAY_DAEMON_ADDRESS 
value: xray-service.default:2000