Ceph API微服务开发--cephfs文件系统服务
目标：使用libcephfs库，实现对cephfs文件系统的挂载、目录、文件上传与下载等操作
环境：CentOS 7 / IntelliJ IDEA (因为libcephfs仅支持linux，所以在centos7中安装IDE开发程序)
步骤：libcephfs简介->Linux环境配置->cephfs挂载与目录基本方法实现->文件上传与下载功能开发
1.libcephfs简介
CephFS通过在RADOS基础上增加了MDS(Metadata Server)来提供文件存储，并提供libcephfs库供开发者调用其接口。
libcephfs javadoc：http://docs.ceph.org.cn/api/libcephfs-java/javadoc/
上述网址中列出了库中包含的类及其方法，其中主要的类为CephMount。
maven依赖：
com.ceph
libcephfs
0.80.5
2.Linux环境配置
除了添加maven依赖之外，还需在linux开发机上安装libcephfs相关开发包：
libcephfs1-0.94.9-0.el7.x86_64.rpm
libcephfs_jni1-0.94.9-0.el7.x86_64.rpm
下载地址：http://mirror.neu.edu.cn/centos/7/storage/x86_64/ceph-hammer/
安装：yum -y install libcephfs1-0.94.9-0.el7.x86_64.rpm libcephfs_jni1-0.94.9-0.el7.x86_64.rpm
设置链接：
ln -s /usr/lib64/libcephfs_jni.so.1.0.0 /usr/lib/libcephfs_jni.so.1
ln -s /usr/lib64/libcephfs_jni.so.1.0.0 /usr/lib/libcephfs_jni.so
同时需要安装ceph-common组件：yum -y install ceph-common
3.cephfs挂载与目录基本方法实现
Service代码：以CephMount类为主要操作类，实现cephfs的操作
package com.boe.cloud.service.cephfs.service.impl;
import com.ceph.fs.CephMount;
import com.ceph.fs.CephStat;
import org.springframework.stereotype.Service;
@Service
public class CephfsServiceImpl implements com.boe.cloud.service.cephfs.service.CephfsService {
private CephMount mount=null;
@Override
public Boolean mountCephfsByRoot(){
try {
this.mount = new CephMount("admin");
this.mount.conf_set("mon_host", "192.168.0.44;192.168.0.45;192.168.0.46");
//System.out.println(mount.conf_get("mon_host"));
this.mount.conf_set("key","AQCxGlBbNBRBGBAAAYW6tv/Z8x2Dz1mnCxwW9w==");
this.mount.mount("/");
return true;
}catch (Exception e){
e.printStackTrace();
}
return false;
}
@Override
public String[] createDirByPath(String path){
String[] dirList = null;
try {
if (this.mount == null){
return null;
}
this.mount.mkdirs(path, 0777);
dirList = this.mount.listdir("/");
return dirList;
}catch (Exception e){
e.printStackTrace();
}
return null;
}
@Override
public String[] deleteDirByPath(String path){
String[] dirList = null;
try {
if (this.mount == null){
return null;
}
this.mount.rmdir(path);
dirList = this.mount.listdir("/");
return dirList;
}catch (Exception e){
e.printStackTrace();
}
return null;
}
@Override
public CephStat getFileStatusByPath(String path){
CephStat stat = new CephStat();
try {
if (this.mount == null){
return null;
}
this.mount.lstat(path, stat);
return stat;
}catch (Exception e){
e.printStackTrace();
}
return null;
}
@Override
public String readFileByPath(String path){
CephStat stat = new CephStat();
String context=null;
try {
if (this.mount == null){
return null;
}
int fd = this.mount.open(path, CephMount.O_RDONLY, 0);
this.mount.fstat(fd, stat);
byte[] buffer = new byte[(int)stat.size];
this.mount.read(fd, buffer, stat.size, 0);
context = new String(buffer);
this.mount.close(fd);
return context;
}catch (Exception e){
e.printStackTrace();
}
return null;
}
}控制类+swagger实现api调用接口：
package com.boe.cloud.service.cephfs.controller;
import com.boe.cloud.service.cephfs.service.impl.CephfsServiceImpl;
import com.ceph.fs.CephStat;
import io.swagger.annotations.ApiOperation;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping(value = "/cephfs/api")
public class CephfsController {
private CephfsServiceImpl cephfsService = new CephfsServiceImpl();
@ApiOperation(value = "Mount", notes = "Mount")
@RequestMapping(value = "/mount", method = RequestMethod.GET)
public Boolean mountCephFsByRoot(){
return cephfsService.mountCephfsByRoot();
}
@ApiOperation(value = "CreateDir", notes = "CreateDir")
@RequestMapping(value = "/createdir", method = RequestMethod.POST)
public String[] createDirByPath(@RequestParam(value = "DirPath") String path){
return cephfsService.createDirByPath(path);
}
@ApiOperation(value = "DeleteDir", notes = "DeleteDir")
@RequestMapping(value = "/deletedir", method = RequestMethod.DELETE)
public String[] deleteDirByPath(@RequestParam(value = "DirPath") String path){
return cephfsService.deleteDirByPath(path);
}
@ApiOperation(value = "FileStatus", notes = "FileStatus")
@RequestMapping(value = "/getfilestatus", method = RequestMethod.GET)
public CephStat getFileStatusByPath(@RequestParam(value = "DirPath") String path){
return cephfsService.getFileStatusByPath(path);
}
@ApiOperation(value = "FileContext", notes = "FileContext")
@RequestMapping(value = "/getfilecontext", method = RequestMethod.GET)
public String readFileByPath(@RequestParam(value = "DirPath") String path){
return cephfsService.readFileByPath(path);
}
}测试：mount "/"目录，使用listdir查看目录
4.文件上传与下载功能开发
(1)上传功能
使用java文件读写方法读取本地文件，libcephfs中的write方法写文件的形式将指定文件上传至cephfs，简单流程图如下：
实现方法：
@Override
public Boolean uploadFileByPath(String filePath, String fileName){
// exit with null if not mount
if (this.mount == null){
logger.info("Ceph fs not mount!");
return null;
}
// file definition
char pathChar = File.separatorChar;
String fileFullName = "";
Long fileLength = 0l;
Long uploadedLength = 0l;
File file = null;
// Io
FileInputStream fis = null;
// get local file info
fileFullName = filePath + pathChar + fileName;
file = new File(fileFullName);
if (!file.exists()){
logger.info("File not exist!");
return false;
}
fileLength = file.length();
// get io from local file
try {
fis = new FileInputStream(file);
}catch (FileNotFoundException e){
logger.info("Read local file failed!");
e.printStackTrace();
}
// if file exists or not
String[] dirList = null;
Boolean fileExist = false;
try {
dirList = this.mount.listdir("/");
for (String fileInfo : dirList){
if (fileInfo.equals(fileName)){
fileExist = true;
}
}
}catch (FileNotFoundException e){
logger.info("File Path not exist!");
e.printStackTrace();
}
// transfer file by diff pattern
if (!fileExist){
try {
// create file and set mode WRITE
this.mount.open(fileName, CephMount.O_CREAT, 0);
int fd = this.mount.open(fileName, CephMount.O_RDWR, 0);
// start transfer
int length = 0;
byte[] bytes = new byte[1024];
while ((length = fis.read(bytes, 0, bytes.length)) != -1){
// write
this.mount.write(fd, bytes, length, uploadedLength);
// update length
uploadedLength += length;
// output transfer rate
float rate = (float)uploadedLength * 100 / (float)fileLength;
String rateValue = (int)rate + "%";
System.out.println(rateValue);
// complete flag
if (uploadedLength == fileLength){
break;
}
}
System.out.println("文件传输成功！");
// chmod
this.mount.fchmod(fd, 0666);
// close
this.mount.close(fd);
if (fis != null){
fis.close();
}
return true;
}catch (Exception e){
logger.info("File transfer failed!");
e.printStackTrace();
}
}else if (fileExist){
try {
// get file length
CephStat stat = new CephStat();
this.mount.stat(fileName, stat);
uploadedLength = stat.size;
int fd = this.mount.open(fileName, CephMount.O_RDWR, 0);
// start transfer
int length = 0;
byte[] bytes = new byte[1024];
fis.skip(uploadedLength);
while ((length = fis.read(bytes, 0, bytes.length)) != -1){
// write
this.mount.write(fd, bytes, length, uploadedLength);
// update length
uploadedLength += length;
// output transfer rate
float rate = (float)uploadedLength * 100 / (float)fileLength;
String rateValue = (int)rate + "%";
System.out.println(rateValue);
// complete flag
if (uploadedLength == fileLength){
break;
}
}
System.out.println("断点文件传输成功！");
// chmod
this.mount.fchmod(fd, 0666);
// close
this.mount.close(fd);
if (fis != null){
fis.close();
}
return true;
}catch (Exception e){
logger.info("BreakPoint transfer failed!");
e.printStackTrace();
}
}else {
try {
if (fis != null){
fis.close();
}
}catch (Exception e){
e.printStackTrace();
}
return false;
}
return false;
}测试：
上传本地压缩文件，并在传输过程中手动中断，进入cephfs挂载目录查看：文件实际大小为291M
继续传输直至结束：查看控制台输出
查看：
(2)下载功能
与上传功能类似，不同的是使用libcephfs的read方法
下载功能方法编写：
@Override
public Boolean downloadFileByPath(String filePath, String fileName){
// exit with null if not mount
if (this.mount == null){
logger.info("Ceph fs not mount!");
return null;
}
// file definition
char pathChar = File.separatorChar;
String fileFullName = "";
Long fileLength = 0l;
Long downloadedLength = 0l;
File file = null;
// IO
FileOutputStream fos = null;
RandomAccessFile raf = null;
// new file object
fileFullName = filePath + pathChar + fileName;
file = new File(fileFullName);
// get cephfs file size
try {
CephStat stat = new CephStat();
this.mount.stat(fileName, stat);
fileLength = stat.size;
}catch (Exception e){
logger.info("Fail to get file size.");
e.printStackTrace();
}
if (fileLength != 0){
if (!file.exists()){
// download file
int length = 10240;
byte[] bytes = new byte[length];
try {
int fd = this.mount.open(fileName, CephMount.O_RDONLY, 0);
fos = new FileOutputStream(file);
float rate = 0;
String rateValue = "";
while ((fileLength - downloadedLength) >= length && (this.mount.read(fd, bytes, (long)length, downloadedLength)) != -1){
fos.write(bytes, 0, length);
fos.flush();
downloadedLength += (long)length;
// output transfer rate
rate = (float)downloadedLength * 100 / (float)fileLength;
rateValue = (int)rate + "%";
System.out.println(rateValue);
if (downloadedLength == fileLength){
break;
}
}
if (downloadedLength != fileLength){
this.mount.read(fd, bytes, fileLength-downloadedLength, downloadedLength);
fos.write(bytes, 0, (int)(fileLength-downloadedLength));
fos.flush();
downloadedLength = fileLength;
// output transfer rate
rate = (float)downloadedLength * 100 / (float)fileLength;
rateValue = (int)rate + "%";
System.out.println(rateValue);
}
System.out.println("Download Success!");
fos.close();
this.mount.close(fd);
return true;
}catch (Exception e){
logger.info("First download fail!");
e.printStackTrace();
}
}else if (file.exists()){
// download file
int length = 10240;
byte[] bytes = new byte[length];
Long filePoint = file.length();
try {
int fd = this.mount.open(fileName, CephMount.O_RDONLY, 0);
raf = new RandomAccessFile(file,"rw");
raf.seek(filePoint);
downloadedLength = filePoint;
float rate = 0;
String rateValue = "";
while ((fileLength - downloadedLength) >= length && (this.mount.read(fd, bytes, (long)length, downloadedLength)) != -1){
raf.write(bytes, 0, length);
downloadedLength += (long)length;
// output transfer rate
rate = (float)downloadedLength * 100 / (float)fileLength;
rateValue = (int)rate + "%";
System.out.println(rateValue);
if (downloadedLength == fileLength){
break;
}
}
if (downloadedLength != fileLength){
this.mount.read(fd, bytes, fileLength-downloadedLength, downloadedLength);
raf.write(bytes, 0, (int)(fileLength-downloadedLength));
downloadedLength = fileLength;
// output transfer rate
rate = (float)downloadedLength * 100 / (float)fileLength;
rateValue = (int)rate + "%";
System.out.println(rateValue);
}
System.out.println("Cut Point Download Success!");
raf.close();
this.mount.close(fd);
return true;
}catch (Exception e){
logger.info("Continue download fail!");
e.printStackTrace();
}
}else {
logger.info("Unknown Error!");
return false;
}
}运行测试：
输入参数
手动中止
继续下载至结束
以上，基本方法开发完成。