DockerSecretProcessor.java

package hung.org;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Map;
import java.util.stream.Collectors;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.env.EnvironmentPostProcessor;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.MapPropertySource;
import org.springframework.stereotype.Component;
import org.springframework.util.FileCopyUtils;

//@Component
public class DockerSecretProcessor implements EnvironmentPostProcessor {

	@Override
	public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
		
		String bindPathPpty = environment.getProperty("docker-secret.bind-path");
		
		System.out.println("value of \"docker-secret.bind-path\" property:" + bindPathPpty);
		
		if (bindPathPpty!=null) {
			Path bindPath = Paths.get(bindPathPpty);
			if (Files.isDirectory(bindPath)) {
				Map<String,Object> dockerSecrets;
				try {
					dockerSecrets = 
					  Files.list(bindPath)
					    .collect(
					      Collectors.toMap(
					        path -> {
					        	File secretFile = path.toFile();
					        	return "docker-secret-" + secretFile.getName();
					        },
					        path -> {
					        	File secretFile = path.toFile();
								try {
									byte[] content = FileCopyUtils.copyToByteArray(secretFile);
									return new String(content);
								} catch (IOException e) {
									throw new RuntimeException(e);
								}
					        }
					      ));
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
				
				dockerSecrets
				  .entrySet()
				    .forEach(entry -> {
				    	System.out.println(entry.getKey()+"=\""+entry.getValue()+"\"");
				    });
				
				MapPropertySource pptySource = new MapPropertySource("docker-secrets",dockerSecrets);
				
				environment.getPropertySources().addLast(pptySource);
				
			}
		}			
	}

}