Use o SDK do ECS para executar comandos do Cloud Assistant em várias instâncias ECS e obter os resultados da execução sem fazer login.
Cenário de exemplo
Um sistema de O&M é fundamental para a estabilidade dos negócios. Para manter a integridade das instâncias ECS, verifique regularmente o uso de recursos, como utilização de CPU, consumo de memória e uso de disco.
O Cloud Assistant executa comandos nas instâncias ECS sem necessidade de login, o que permite automatizar tarefas de O&M, incluindo monitoramento de recursos, coleta de logs e solução de problemas.
Pré-requisitos
Verifique se os seguintes requisitos foram atendidos:
As instâncias ECS de destino estão no estado Running e têm o Cloud Assistant Agent instalado. Consulte Instalar o Cloud Assistant Agent.
-
As variáveis de ambiente
ALIBABA_CLOUD_ACCESS_KEY_IDeALIBABA_CLOUD_ACCESS_KEY_SECRETestão configuradas. Consulte Configurar variáveis de ambiente no Linux, macOS e Windows.NotaPara proteger sua conta Alibaba Cloud, crie um usuário RAM, conceda permissões de ECS a ele e use seu par de AccessKey para chamar operações do SDK do ECS. Consulte Usuários RAM.
O usuário RAM tem permissões do Cloud Assistant. Consulte Acesso de usuários RAM ao Cloud Assistant.
O comando do Cloud Assistant (shell, batch ou PowerShell) está preparado.
As dependências do SDK do ECS estão instaladas. Acesse a página do Elastic Compute Service no SDK Center.
Operações de API usadas
Este tópico usa as seguintes operações da API do ECS:
|
Operação |
Descrição |
|
Executa um comando em uma ou mais instâncias ECS e retorna um |
|
|
Consulta os resultados da execução de um comando por |
Tipos de comando
O Cloud Assistant oferece suporte a três tipos de comando, definidos pelo parâmetro Type em RunCommand:
|
Valor de Type |
Descrição |
|
|
Comando Shell para instâncias Linux |
|
|
Comando Batch para instâncias Windows |
|
|
Comando PowerShell para instâncias Windows |
Valores de status de invocação
Durante a consulta periódica de resultados, o campo InvocationStatus indica o estado do comando:
|
Status |
Descrição |
|
|
O comando está sendo verificado ou enviado. |
|
|
O comando está em execução. |
|
|
O comando está sendo interrompido. |
|
|
O comando foi concluído com êxito. |
|
|
O comando falhou. |
|
|
O comando foi interrompido. |
InvocationStatus é o campo no nível de invocação retornado por DescribeInvocations. Ele usa Success para indicar conclusão bem-sucedida. O valor Finished pertence a InstanceInvokeStatus no subnível por instância InvokeInstance, um campo separado com um conjunto diferente de valores de enumeração.
Código de exemplo
Os exemplos a seguir em Java e Python demonstram como executar um comando em instâncias ECS e consultar periodicamente os resultados da execução com o SDK do ECS.
Java
Este exemplo cria uma classe CloudAssistantService que inicializa um cliente ECS, executa um comando e consulta os resultados periodicamente até que o comando seja concluído ou atinja o tempo limite.
Comportamentos principais:
Cria um cliente ECS singleton thread-safe com bloqueio de verificação dupla.
Executa
cat /proc/meminfonas instâncias especificadas.Consulta a intervalos de 2 segundos, até
commandTimeOut / delaytentativas.
import com.aliyun.ecs20140526.Client;
import com.aliyun.ecs20140526.models.*;
import com.aliyun.teaopenapi.models.Config;
import com.google.gson.Gson;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
public class CloudAssistantService {
/**
* Read the AccessKey ID and AccessKey secret from environment variables.
*/
private static final String ACCESS_KEY_ID = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
private static final String ACCESS_KEY_SECRET = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");
private static final ScheduledExecutorService SCHEDULER = Executors.newScheduledThreadPool(1);
private static volatile Client ecsClient;
private CloudAssistantService() {
}
/**
* Initialize the ECS client.
*
* @param regionId The region ID that specifies where the ECS client connects.
* @return The initialized ECS client.
* <p>
* This method uses the double-checked locking pattern to ensure thread-safe
* singleton creation of the ECS client. It first checks whether a client
* already exists, then re-checks within a synchronized block before creating one.
*/
public static Client getEcsClient(String regionId) throws Exception {
if (ecsClient == null) {
synchronized (CloudAssistantService.class) {
if (ecsClient == null) {
Config config = new Config().setAccessKeyId(ACCESS_KEY_ID).setAccessKeySecret(ACCESS_KEY_SECRET).setRegionId(regionId);
ecsClient = new Client(config);
}
}
}
return ecsClient;
}
public static void main(String[] args_) {
try {
// The region ID.
String regionId = "cn-chengdu";
getEcsClient(regionId);
// The IDs of the ECS instances on which to run the command.
List<String> instanceIds = Arrays.asList("i-2vcXXXXXXXXXXXXXXXb8", "i-2vcXXXXXXXXXXXXXXXot");
// The command to run.
String commandContent = "#!/bin/bash\n cat /proc/meminfo";
// The command execution timeout, in seconds.
long commandTimeOut = 60;
// Run the command.
String invokeId = runCommand(commandContent, regionId, instanceIds, commandTimeOut);
// Query the command execution results.
DescribeInvocationsResponse invocationResult = describeInvocations(regionId, invokeId, commandTimeOut);
System.out.println("The command execution result:" + new Gson().toJson(invocationResult));
// Note: This sample does not include logging configuration.
} catch (Exception e) {
throw new RuntimeException(e);
} finally {
SCHEDULER.shutdown();
}
}
/**
* Run a command on the specified ECS instances.
*
* @param commandContent The command to run.
* @param regionId The region ID of the target ECS instances.
* @param instanceIds The IDs of the target ECS instances.
* @param commandTimeOut The command execution timeout, in seconds.
* @return The invocation ID (InvokeId) of the command task.
*/
public static String runCommand(String commandContent, String regionId, List<String> instanceIds, long commandTimeOut) {
try {
System.out.println("runCommand start...");
RunCommandRequest request = new RunCommandRequest();
request.setRegionId(regionId);
request.setType(Constants.COMMAND_TYPE.RUN_SHELL_SCRIPT);
request.setCommandContent(commandContent);
request.setInstanceId(instanceIds);
request.setTimeout(commandTimeOut);
RunCommandResponse runCommandResponse = ecsClient.runCommand(request);
return runCommandResponse.body.invokeId;
} catch (Exception e) {
throw new RuntimeException("runCommand failed", e);
}
}
/**
* Query the execution results of a Cloud Assistant command.
*
* @param regionId The region ID of the target instances.
* @param invokeId The invocation ID that uniquely identifies the command task.
* @param commandTimeOut The command execution timeout, in seconds.
*/
public static DescribeInvocationsResponse describeInvocations(String regionId, String invokeId, long commandTimeOut) {
DescribeInvocationsRequest describeInvocationsRequest = new DescribeInvocationsRequest()
.setRegionId(regionId)
.setInvokeId(invokeId);
long delay = 2;
// Maximum number of polling retries.
int maxRetries = (int) (commandTimeOut / delay);
int retryCount = 0;
try {
while (retryCount < maxRetries) {
ScheduledFuture<DescribeInvocationsResponse> future = SCHEDULER.schedule(() ->
ecsClient.describeInvocations(describeInvocationsRequest), delay, TimeUnit.SECONDS);
DescribeInvocationsResponse results = future.get();
List<DescribeInvocationsResponseBody.DescribeInvocationsResponseBodyInvocationsInvocation> invocationList = results.body.invocations.invocation;
if (invocationList.isEmpty()) {
throw new RuntimeException("The command execution result was not found.");
}
DescribeInvocationsResponseBody.DescribeInvocationsResponseBodyInvocationsInvocation invocationResult = results.body.invocations.invocation.get(0);
String invocationStatus = invocationResult.invocationStatus;
switch (invocationStatus) {
case Constants.INVOCATION_STATUS.PENDING:
case Constants.INVOCATION_STATUS.RUNNING:
case Constants.INVOCATION_STATUS.STOPPING:
retryCount++;
continue;
default:
return results;
}
}
throw new RuntimeException("Max retries exceeded for command execution result.");
} catch (Exception e) {
throw new RuntimeException("describeInvocationResults failed", e);
}
}
public static class Constants {
// Command types.
public static final class COMMAND_TYPE {
// Shell command, applicable to Linux instances.
public static final String RUN_SHELL_SCRIPT = "RunShellScript";
// Batch command, applicable to Windows instances.
public static final String RUN_BAT_SCRIPT = "RunBatScript";
// PowerShell command, applicable to Windows instances.
public static final String RUN_POWERSHELL_SCRIPT = "RunPowerShellScript";
}
// Invocation status values for Cloud Assistant commands.
public static final class INVOCATION_STATUS {
// The system is verifying or sending the command.
public static final String PENDING = "Pending";
// The command is being run on the ECS instances.
public static final String RUNNING = "Running";
// The command is being stopped.
public static final String STOPPING = "Stopping";
}
}
}
Python
Este exemplo usa funções separadas para inicialização do cliente, execução de comandos, consulta de invocações e verificação periódica de conclusão.
Comportamentos principais:
Valida o tipo de comando comparando com
RunShellScript,RunBatScripteRunPowerShellScriptantes da execução.Verifica se a lista de IDs de instância não está vazia.
Aplica backoff exponencial durante as consultas: o tempo de espera dobra a cada tentativa (
2 ^ retry_countsegundos).Define como padrão
max(command_timeout // 2, 1)tentativas (30 para um tempo limite de 60 segundos).Trata estados terminais:
Success(êxito),FailedeStopped.
import os
import time
import logging
from alibabacloud_ecs20140526 import models as ecs_20140526_models
from alibabacloud_ecs20140526.client import Client as Ecs20140526Client
from alibabacloud_tea_openapi import models as open_api_models
# Configure logging.
logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')
ACCESS_KEY_ID = os.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID")
ACCESS_KEY_SECRET = os.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET")
if not ACCESS_KEY_ID or not ACCESS_KEY_SECRET:
raise EnvironmentError(
"Missing required environment variables: ALIBABA_CLOUD_ACCESS_KEY_ID and ALIBABA_CLOUD_ACCESS_KEY_SECRET")
def get_ecs_client(region_id):
config = open_api_models.Config(
access_key_id=ACCESS_KEY_ID,
access_key_secret=ACCESS_KEY_SECRET,
region_id=region_id
)
return Ecs20140526Client(config)
def execute_command(client, command_content, region_id, instance_ids, command_timeout, command_type):
if not instance_ids:
raise ValueError("Instance IDs list cannot be empty.")
valid_command_types = ["RunShellScript", "RunBatScript", "RunPowerShellScript"]
if command_type not in valid_command_types:
raise ValueError(f"Invalid command type: {command_type}. Valid types are {valid_command_types}.")
request = ecs_20140526_models.RunCommandRequest()
request.region_id = region_id
request.type = command_type
request.command_content = command_content
request.instance_id = instance_ids
request.timeout = command_timeout
try:
run_command_response = client.run_command(request)
return run_command_response.to_map()['body']['InvokeId']
except Exception as e:
logging.error(f"Failed to execute command: {e}")
raise
def query_invocations(client, region_id, invoke_id):
request = ecs_20140526_models.DescribeInvocationsRequest()
request.region_id = region_id
request.invoke_id = invoke_id
try:
describe_invocations_response = client.describe_invocations(request)
return describe_invocations_response.to_map()['body']
except Exception as e:
logging.error(f"Failed to query invocations: {e}")
raise
def wait_for_command_completion(client, region_id, invoke_id, max_retries, backoff_factor=2):
retry_count = 0
while retry_count < max_retries:
time.sleep(backoff_factor ** retry_count)
results = query_invocations(client, region_id, invoke_id)
invocation_list = results.get('Invocations', {}).get('Invocation', [])
if not invocation_list:
raise RuntimeError("The command execution result was not found.")
invocation_result = invocation_list[0]
invocation_status = invocation_result.get('InvocationStatus')
logging.info(f"Current invocation status: {invocation_status}")
if invocation_status == "Success":
print("query_invocations result:", results)
break
elif invocation_status in ["Failed", "Stopped"]:
raise RuntimeError(f"Command execution failed with status: {invocation_status}")
else:
retry_count += 1
else:
raise TimeoutError("Command execution timed out.")
def main():
# The region ID.
region_id = "cn-chengdu"
# The IDs of the ECS instances on which to run the command.
instance_ids = ["i-2vcXXXXXXXXXXXXXXXb8", "i-2vcXXXXXXXXXXXXXXXot"]
# The command to run.
command_content = "#!/bin/bash\n cat /proc/meminfo"
# The command execution timeout, in seconds.
command_timeout = 60
# The command type. Valid values: RunShellScript, RunBatScript, and RunPowerShellScript.
command_type = "RunShellScript"
client = get_ecs_client(region_id)
invoke_id = execute_command(client, command_content, region_id, instance_ids, command_timeout, command_type)
max_retries = max(int(command_timeout // 2), 1)
wait_for_command_completion(client, region_id, invoke_id, max_retries)
if __name__ == "__main__":
main()