[curve/toos-v2]: add snapshot-clone-status

[Cyber-SiKu]

Is your feature request related to a problem? (你需要的功能是否与某个问题有关?)

we'd like to support bs status snapshot command in curve tool

• The implementation of the old tool is here：

  curve/src/tools/status_tool.cpp

  Lines 658 to 685 in 8d6caf7

  	int StatusTool::PrintSnapshotCloneStatus() {
  	std::cout << "SnapshotCloneServer status:" << std::endl;
  	if (noSnapshotServer_) {
  	std::cout << "No SnapshotCloneServer" << std::endl;
  	return 0;
  	}
  	std::string version;
  	std::vector<std::string> failedList;
  	int res = versionTool_->GetAndCheckSnapshotCloneVersion(&version,
  	&failedList);
  	int ret = 0;
  	if (res != 0) {
  	std::cout << "GetAndCheckSnapshotCloneVersion fail" << std::endl;
  	ret = -1;
  	} else {
  	std::cout << "version: " << version << std::endl;
  	if (!failedList.empty()) {
  	versionTool_->PrintFailedList(failedList);
  	ret = -1;
  	}
  	}
  	std::vector<std::string> activeAddrs = snapshotClient_->GetActiveAddrs();
  	std::map<std::string, bool> onlineStatus;
  	snapshotClient_->GetOnlineStatus(&onlineStatus);
  	std::cout << "current snapshot-clone-server: " << activeAddrs << std::endl;
  	PrintOnlineStatus("snapshot-clone-server", onlineStatus);
  	return ret;
  	}

• The old command input and out put:

curve_ops_tool snapshot-clone-status

-------
output:
SnapshotCloneServer status:
version: ***
current snapshot-clone-server: ***
online snapshot-clone-server list: ***
offline snapshot-clone-server list: ***

Refer to tool develop guide to get start, and paste the result of the command in pr.

Build compilation environment：https://github.com/opencurve/curve/blob/master/docs/cn/build_and_run.md

Describe the solution you'd like (描述你期望的解决方法)

Add subcommand clinet to curve bs list.

Describe alternatives you've considered (描述你想到的折衷方案)

Additional context/screenshots (更多上下文/截图)

[zhanghuidinah]

• This issue has been chosen for community developer activities. Welcome to feel free to try it. After the PR is merged, you will receive a gift package and a certificate as a community contributor.

• Developer Activities Registration Steps please ref [2023 Q2 Developer Activities]: Call For Participation！ #2334 (comment)

[Xinlong-Chen]

@Cyber-SiKu I am interested in this task, please assign it to me, thanks.

[ilixiaocui]

Xinlong-Chen

welcome!

[Xinlong-Chen]

@Cyber-SiKu When I tried to understand this task, I found that this task is similar to the implementation of the curve bs status mds command.

But I have a little doubt about the implementation of mds.

---

In tools-v1: there need 3 rpcs to get status(in curve/src/tools/status_tool.cpp@PrintMdsStatus):

1. versionTool_->GetAndCheckMdsVersion(&version, &failedList)
2. mdsClient_->GetCurrentMds()
3. mdsClient_->GetMdsOnlineStatus(&onlineStatus)

---

But this is different in tools-v2.

There are only 2 rpcs in tools-v2(in curve/tools-v2/pkg/cli/command/curvebs/status/mds/mds.go@Init):

1. statusMetric := basecmd.NewMetric(addrs, STATUS_SUBURI, timeout)
2. versionMetric := basecmd.NewMetric(addrs, VERSION_SUBURI, timeout)

---

This 2 rpcs in tools-v2 is the same as the first two rpcs in tools-v1.

I would like to ask why it can be done like this (get rid of the tail rpc)?

[Cyber-SiKu]

@Cyber-SiKu When I tried to understand this task, I found that this task is similar to the implementation of the curve bs status mds command.

But I have a little doubt about the implementation of mds.

In tools-v1: there need 3 rpcs to get status(in curve/src/tools/status_tool.cpp@PrintMdsStatus):

1. versionTool_->GetAndCheckMdsVersion(&version, &failedList)
2. mdsClient_->GetCurrentMds()
3. mdsClient_->GetMdsOnlineStatus(&onlineStatus)

But this is different in tools-v2.

There are only 2 rpcs in tools-v2(in curve/tools-v2/pkg/cli/command/curvebs/status/mds/mds.go@Init):

1. statusMetric := basecmd.NewMetric(addrs, STATUS_SUBURI, timeout)
2. versionMetric := basecmd.NewMetric(addrs, VERSION_SUBURI, timeout)

This 2 rpcs in tools-v2 is the same as the first two rpcs in tools-v1.

I would like to ask why it can be done like this (get rid of the tail rpc)?

GetCurrentMds

curve/src/tools/mds_client.cpp

Lines 973 to 990 in 4e73df5

	std::vector<std::string> MDSClient::GetCurrentMds() {
	std::vector<std::string> leaderAddrs;
	for (const auto item : dummyServerMap_) {
	// 获取status来判断正在服务的地址
	std::string status;
	MetricRet ret = metricClient_.GetMetric(item.second,
	kMdsStatusMetricName, &status);
	if (ret != MetricRet::kOK) {
	std::cout << "Get status metric from " << item.second
	<< " fail" << std::endl;
	continue;
	}
	if (status == kMdsStatusLeader) {
	leaderAddrs.emplace_back(item.first);
	}
	}
	return leaderAddrs;
	}

GetMdsOnlineStatus

curve/src/tools/mds_client.cpp

Lines 901 to 925 in 4e73df5

	int MDSClient::GetListenAddrFromDummyPort(const std::string& dummyAddr,
	std::string* listenAddr) {
	assert(listenAddr != nullptr);
	MetricRet res = metricClient_.GetConfValueFromMetric(dummyAddr,
	kMdsListenAddrMetricName, listenAddr);
	if (res != MetricRet::kOK) {
	return -1;
	}
	return 0;
	}
	void MDSClient::GetMdsOnlineStatus(std::map<std::string, bool>* onlineStatus) {
	assert(onlineStatus != nullptr);
	onlineStatus->clear();
	for (const auto item : dummyServerMap_) {
	std::string listenAddr;
	int res = GetListenAddrFromDummyPort(item.second, &listenAddr);
	// 如果获取到的监听地址与记录的mds地址不一致，也认为不在线
	if (res != 0 || listenAddr != item.first) {
	onlineStatus->emplace(item.first, false);
	continue;
	}
	onlineStatus->emplace(item.first, true);
	}
	}

It can be found that both are essentially obtaining metirc to judge the status of the server.It's just that v1 still needs to judge whether the dummyport is consistent with the configuration file.

[Xinlong-Chen]

Got it!

Based on forementioned reasons, we also can implement bs status snapshot command with 2 rpcs.

There are the corresponding metric strings I found about snapshot. I don't know if that's right?

STATUS_SUBURI  = "/vars/snapshotcloneserver_status"
VERSION_SUBURI = "/vars/curve_version"

[Cyber-SiKu]

Got it!

Based on forementioned reasons, we also can implement bs status snapshot command with 2 rpcs.

There are the corresponding metric strings I found about snapshot. I don't know if that's right?

STATUS_SUBURI  = "/vars/snapshotcloneserver_status"
VERSION_SUBURI = "/vars/curve_version"

It should be like this, you can refer to the old code. It seems that there are differences in versions

[Xinlong-Chen]

Well, I also have a question that how can I test it?
When I use tools-v1 command curve_ops_tool snapshot-clone-status in docker(use reference image)，the following result I get bothers me.

root@f8df310173eb:/# curve_ops_tool snapshot-clone-status
SnapshotCloneServer status:
No SnapshotCloneServer

Do I need do more action about snapshot deployment to get correct result as following:

curve_ops_tool snapshot-clone-status

-------
output:
SnapshotCloneServer status:
version: ***
current snapshot-clone-server: ***
online snapshot-clone-server list: ***
offline snapshot-clone-server list: ***