[5 minutes to play lighthouse] quickly use Chang'an chain

1、 Product background and significance

In the community operation of Chang'an chain, we found , When new users deploy Chang'an chain , Because the local environment is different , It causes some unnecessary blocking to the fast experience test Chang'an chain . So we plan to use the ECS , Provide a set of standard environment suitable for Changan chain , For community developers to experience and test Chang'an chain .

In addition, Tencent cloud Lighthouse Low cost features , When community users have lightweight Chang'an chain applications, they need to pilot and demo when , You can also use Lighthouse Achieve... At a low cost .

This product mainly includes ： A Tencent cloud CVM The server 、 A set of Chang'an chain management platform , A long safety chain , One CMS Interactive console .

For the convenience of users , The Chang'an chain has been subscribed to the Chang'an chain management console , Four common test contracts are provided , For new users to get started quickly .

2、 choice Lighthouse + Changan chain service

Let's enter first Tencent cloud Lighthouse Lightweight application server page ,

Select the corresponding server to configure according to your needs .

• regional ： Select as needed
• Image type ： Apply image
• apply name ： Changan chain Chainmaker
• Example packages , Server configuration , Minimum server machine configuration requirements 2 nucleus 8G.

3、 Visit Chang'an chain management console

Lighthouse Front page of management console

Get into Lighthouse（ Lightweight application servers ） Console , Find the Chang'an chain service you purchased in the server module , Click to enter service details .

Application management

In application management , Find the Chang'an chain management console application , among

• The login address is the access address of the management console
• The default account name is admin, The default password can be clicked on the login button , Log in to the server and enter the following command to obtain the password . cat /home/chainmaker/credentials.txt
• More instructions can be viewed , User manual
• Changan chain node address is , Node RPC Address , May pass through SDK Configure the address direct access chain on .

4、 Instructions for management console

4.1、 Login module

Sign in

• Use the account and password obtained above to log in to the management console .

4.2、 Built in Changan chain configuration description

• At present, a Chang'an chain has been built in the management console , The main configuration information is as follows

Serial number	Content	explain
1	Changan chain version	V2.2.1
2	chain id	chain1
3	Number of organizations	4 Organizations
4	Number of nodes	4 Consensus nodes
5	Consensus algorithm	TBFT
6	The maximum trading capacity of a single block	100 transaction
7	Transaction expiration time	600s
8	Transaction interval	2000ms
9	Do you support docker_VM	Support

4.3、 Blockchain list

Blockchain list

• At the blockchain management office , You can see the built-in deployed Chang'an chain . Click on the card to start using .
• Relevant certificates used in the chain , You can view and download in the certificate module .

Certificate management

• By default, the... Of this chain is used ,org1 Organized consensus1 Nodes to subscribe to the chain , And by org1 Organized admin1 User certificates are used to send transactions to the chain .

4.4、 View the sample contract

List of contracts

• The deployed contract information of this blockchain is shown here . New contracts are supported , Upgrade contract , Freeze the contract , Unfreeze the contract , Cancel the contract , Edit and view the contract, etc .
• Four test contracts are built in by default , Including the deposit contract , Transfer contract ,ERC-20 contract ,ERC-721 contract . Introduction to relevant contracts , See the contract introduction section .

4.5、 Use the example contract

List of uplink records

• Here is the record of calling the contract through the platform , And the results of the implementation , You can also click to see the details , Jump to the blockchain browser to view the detailed information on the chain .
• Here, you can click initiate uplink to directly call the sample contract .
• Before using , It is recommended that you go to the contract introduction chapter first , Be familiar with the specific business content of the sample contract , Call again .

4.6、 Initiate the uplink

Initiate the uplink

• Here you can select the contract you want to call , And the corresponding contract method , And fill in the reference , Click ok , Initiate uplink transactions .
• After the uplink request is initiated , The transaction will be built with the user selected during the subscription chain , And sign the transaction .
• After the transaction is sent successfully , You can view the details in the blockchain browser

4.7、 See the transaction details

Transaction details

• Each time the information on the chain will be in the form of blockchain transactions , Send to the blockchain .
• Transaction details can be viewed here , Including the block information of the transaction , Transaction originator information , The contract called by the exchange , The exchange carries information on the chain .

4.8、 View block details

image.png

• Transactions over a period of time will be collectively packaged into blocks , And link with other blocks in the form of new block chain to form a growing blockchain .
• Here you can view the specific information of the block , Include block hashes , Read / write set hash ,DAG Information , And the transaction information in this block .

5、 Sample contract introduction

5.1、 Overall description

For the convenience of users , Give an overall description of the following contract contents （ Or regulation ）.

• Function type ： Including execution and query , The execution function will perform the chain consensus operation , Query functions do not , Only the processing logic of the connected node is called ;
• Return value ： When successful, there is a specific return value description , In case of failure, the failure reason will be returned （ Failure is no longer specified in the function set table ）;
• Introduction ： If this parameter is optional, it will be explained , All other cases are required .

5.2、 List of contracts

Currently pre deployed 4 Sample contracts , As shown in the following table ：

Serial number	Contract name	Contract function
1	SaveContract	Deposit contract , Can be saved Key-Value And descriptive information
2	TransferContract	Ordinary transfer contract , Used for general transfer business , No authority and other related design
3	ERC20Contract	ERC20 contract , Basically meet the official standards of Ethereum , Can be used as Token released Demo
4	ERC721Contract	ERC721 contract , Basically meet the official standards of Ethereum , Can be used as NFT released Demo

5.3、 Deposit contract （Save）

5.3.1、 Contract function set

Function name	Function type	Function description	Introduction	Return value	remarks
save	perform	existing evidence	key： Data storage key data： Contents of data storage desc： Description of data storage （ Optional ）	Data storage key	Repetitive key The original data will be overwritten
find	Inquire about	Query object	key： Data storage key	Storing content JSON Format	Object structure ： type EvidenceInstance struct { Key string json:"key" Data string json:"data" Desc string json:"desc" }

Conduct save operation , That is, when saving the object to the bottom chain , If saved successfully, it will trigger preservation event , The subject of this event is ：topic_save

5.3.2 Contract usage guide

The use of depository contracts is very simple , It mainly includes two methods ：

• 1） Certificate data ： call save Function to store data ;
• 2） Query data ： call find Function to query the stored content ;

5.4、 Ordinary transfer contract

5.4.1 Contract function set

Function name	Function type	Function description	Introduction	Return value	remarks
reset	perform	Set account assets	account： account number ; assets： Amount of funds ,uint64 Format string	The assets of the account ;	The account number can be any string
add	perform	Add a specified number of assets to a specific account number	account： Specific account number ; assets： The amount of funds added to the account ,uint64 Format string	All remaining assets of the account number ;
transfer	perform	Transfer of assets	from： Account number transferred out to： Account number transferred in assets： Number of transferred assets ,uint64 Format string	The remaining assets of the transfer out account number
find	Inquire about	Query the asset quantity of the account	account： Specific account number	The remaining assets of the account

The input parameters of all functions in the contract are required , Do not be empty , And it has strict format verification , Account is not recommended "/&%#@“ Equal special symbol When calling reset、add、transfer In operation , If the operation is successful, it will trigger Transfer event , The subject of this event is ：topic_transfer

5.4.2 Contract usage guide

The contract invokes the core process simply , It can be simply divided into the following three steps ：

• 1） Allocate assets ： call reset function , A certain number of assets can be set for an account ;
• 2） Transfer of assets ： call transfer function , You can transfer a specified number of assets from one account to another ;
• 3） Additional assets ： call add function , You can add a specified number of assets to an account number ;

If you want to query the assets of an account , You can call find function , Just pass in the address of the account .

5.5、ERC20 contract

5.5.1 Contract initialization

Some basic configurations can be set during contract initialization , Including distribution token The name of 、 abbreviation 、 Total amount and other information , If it is not set, the default configuration in the contract code will be used . The parameter configuration list involved in the initialization process is described as follows ：

Parameter name	Parameter meaning	The default value is
owner	Address of contract owner	Address of the user who initiated the contract installation
totalSupply	token Total supply	1_000_000_000,10 Billion
decimals	token Calculate the number of decimal points supported	2, Indicates minimal support 0.01
name	token name	DEMO
symbol	token abbreviation	DE

5.5.2 Contract function set

Function name	Function type	Function description	Introduction	Return value	remarks
name	Inquire about	Inquire about token name		The token The name of	Any account can be queried
symbol	Inquire about	Inquire about token abbreviation		The token For short	Any account can be queried
decimals	Inquire about	Inquire about token Support decimal places		The token Supported decimal places	Any account can be queried
totalSupply	Inquire about	Inquire about token Total number of issues		The token Total number of issues	Any account can be queried
owner	Inquire about	Query the owner of the contract		The owner of the contract	Any account can be queried
balanceOf	Inquire about	Query the name of the specified user token Number	owner: Specified user address	The address owns token Number	Any account can be queried
transfer	perform	Transfer the specified quantity token Assign account number to	to: The account address of the transfer in ; value: Transferred token Number	The remaining in the current account token Number	This function can only transfer itself out （ Transaction originator ） Of token
transferFrom	perform	Transfer the specified quantity instead of a certain account number token To a specific account number	from: Transfer out address ; to: Transfer in address ; value: Transfer token Number	from Account number remaining token Number	The transaction initiator of this function must go through from Authorization of account number , namely approve
approve	perform	The authorized account can transfer a specified number of token	spender: Authorized user address value: Allowing transfer token Number	Allowing transfer token Number	Repeated calls to this function will reset the authorized value
allowance	Inquire about	Returns that the specified account authorizes the remaining from a specific account token Number	owner: Authorized user address ; spender: Authorized user address	Authorize the remaining token Number	Any account can be queried
transferOwner	perform	Transfer the owner of the current contract	to: New owner address	New owner address	Only the contract owner can initiate the transaction
mint	perform	Issue additional to the designated account number token	to: Additional user address value: Additional issue token Number	The remainder of the additional address token Number	Only the contract owner can initiate the transaction , The contract call will adjust the total issuance amount
burn	perform	Destroy a specified amount of token	value: Destroyed token Number	The account number remains token Number	Only the account number of the transaction initiator can be destroyed token
deliver	perform	Distribute to the designated account token	to: Distributed users （ Optional , If it is not set, the current account number ） value: Distributed token Number	The account number remains token Number	Only the contract owner can initiate the transaction , The contract call will not affect the total issuance amount , This operation is to delete... From the contract account token Transfer out
address	Inquire about	Returns the current user address		The address of the user	Any account can be queried

5.5.3 Contract usage guide

In Changan chain docker-vm In the virtual machine model , The address algorithm of the transaction initiator has not been disclosed yet , Therefore, the user needs to manually call the contract address() Method to get .

ERC20 A contract is an issue token The contract of , Can be specified through this contract token Release operation of . Its core operation process includes the following steps ：

• 1） Release the contract ： Initialize contract , When initializing a contract, you can set the contract name through initialization parameters 、 The abbreviation and total issuance amount are set , After the issuance of the contract , All... In this contract token At the designated address CTT in , These need to be sent through the dispatch operation token Transfer out .
• 2） distributed token： Call the contract deliver Method to distribute the contract , By this method token From the default address CTT Transfer to the designated account number ;
• 3） Transfer your own token： Call the contract transfer The method can put your own token Transfer to another account ;
• 4） Transfer another's token： call transferFrom The method can be Others Of token Transfer to the designated account number , but Others You must empower yourself enough token The transfer operation can , Authorization operations can be performed through approve Function ;
• 5） Additional issue token： When need is right token When issuing additional shares , By calling mint Function to do ;
• 6） The destruction token： It can be done by burn Function destroys its own part token;

5.6、ERC721 contract

5.6.1 Contract initialization

Some basic configurations can be set during contract initialization , Including distribution NFT The name of 、 Abbreviation and other information , If it is not set, the default configuration in the contract code will be used . The parameter configuration list involved in the initialization process is described as follows ：

Parameter name	Parameter meaning	The default value is
name	token name	NFT-DEMO
symbol	token abbreviation	NFDO

5.6.2 Contract function set

Function name	Function type	Function description	Introduction	Return value	remarks
name	Inquire about	Inquire about NFT name		The NFT The name of	Any account can be queried
symbol	Inquire about	Inquire about NFT abbreviation		The NFT For short	Any account can be queried
tokenURI	Inquire about	The query NFT Of URI Configuration information	tokenId: NFT Unique identification	The NFT Of URI Configuration information	Any account can be queried
totalSupply	Inquire about	Query published NFT Number		The NFT The number of	Any account can be queried
tokenByIndex	Inquire about	Query all NFT Of a sequence number in a set NFT identification	index: The NFT Sequence number in the whole list	Corresponding serial number NFT identification （tokenId）	Any account can be queried
tokenOfOwnerByIndex	Inquire about	Query a serial number under an account NFT identification	owner: Account number queried ; index: The sequence number of the query	Corresponding serial number NFT identification （tokenId）	Any account can be queried
balanceOf	Inquire about	Look up the... Owned by an address NFT Number	owner: Account number queried	The address owns NFT Number （ Those destroyed are not included ）	Any account can be queried
ownerOf	Inquire about	Query a NFT The owner of the	tokenId: NFT Unique identification	Have the right to NFT The address of	Any account can be queried
transferFrom	perform	take NFT Transfer from one address to another	from: Transfer out address （ Optional , If it is not filled in, it is the current account number ）; to: Transfer in address ; tokenId: NFT Unique identification	character string ：“success”	if from It's not the time to NFT The owner of requires authorization from its owner
safeTransferFrom	perform	Safely NFT Transfer from one address to another	from: Transfer out address （ Optional , If it is not filled in, it is the current account number ）; to: Transfer in address ; tokenId: NFT Unique identification data: The content of verification , Usually by to The address is given by the user , It can be done by setCheckData Set up	character string ：“success”	if from It's not the time to NFT The owner of requires authorization from its owner
approve	perform	An authorized user can operate a NFT	approved: Authorized account number tokenId: Authorized NFT Unique identification	character string ：“success”	This operation will overwrite the previously authorized account
setApprovalForAll	perform	Set a user to own token Authorization status of	operator: to grant authorization / Reclaim the authorized account number approved: The state of being authorized ,0： Not authorized ,1： to grant authorization	0： Not authorized ,1： to grant authorization	This authorization has priority over approve Higher
getApproved	Inquire about	Get a NFT Address of the authorized operation	tokenId: NFT Unique identification	The NFT Authorized operation address of	Any account can be queried , However, you can only query your authorization
isApprovedForAll	Inquire about	Get the authorization status of a specified user for an operator	owner : Designated users （ Optional , If you don't fill it in, it means you ） operator : Authorized operation address	0： Not authorized ,1： to grant authorization	Any account can be queried
mint	perform	Additional issuance of designated NFT To an account number	to: The additional account number to （ Optional , If you don't fill it out, you will be issued to yourself ） tokenId: NFT Unique identification tokenURI: NFT Of URI attribute	NFT Unique identification of （tokenId）	Any account can be reissued , but tokenId Can't repeat
burn	perform	Destroy a specified NFT	tokenId: NFT Unique identification	character string ：“success”	This account number must be this NFT The owner of the , Authorization cannot
setTokenURI	perform	Set up NFT Of URI attribute	tokenId: NFT Unique identification tokenURI: NFT Of URI attribute	character string ：“success”	This account number must be this NFT The owner of the , Authorization cannot , But to ensure uniqueness , Calling this function... Is not recommended
setCheckData	perform	Set the account number check data	data: Set up check data	character string ：“success”	This account can only set its own data, The data for safeTransferFrom Medium data check
checkData	Inquire about	Query settings check data		The account number is set check data	Any account can be queried
address	Inquire about	Returns the current user address		The address of the user	Any account can be queried

5.6.3 Contract usage guide

Same as ERC20 The contract is the same , The address of the transaction initiator requires the user to manually call the address in the contract address() Method to get .

ERC721 Is a distribution NFT The contract of , May be issued through this contract NFT Or transfer NFT Wait for the operation . Its core process includes the following steps ：

• Release the contract ： That is, initialize the contract , This class can be set during initialization NFT The name of （name） And abbreviation （symbol）;
• Release NFT： Call the contract mint Method to issue the specified NFT, It is recommended to set... At the time of release NFT Of URI Information , Calling... Is not recommended setTokenURI Adjustment ;
• to grant authorization NFT： That is to authorize others to operate their own NFT, It can be done by approve Method to perform a NFT Authorization of , It can also be done through setApprovalForAll Function to authorize a user to perform all operations instead of himself , Of the two, the latter has a higher priority , Of course, users can realize their own logic by adjusting the contract mode ;
• General transfer NFT： This can be done by invoking the transferFrom Method , Realization NFT The transfer of , If the current operator is not the corresponding NFT The owner of the , Its owner is required to authorize the current operator ;
• Secure transfer NFT： This can be done by invoking the safeTransferFrom Method realization NFT Safe transfer of , The so-called security transfer refers to adding data Parameters , Can be based on data To achieve safe operation ;
• The destruction NFT： When users no longer want to use NFT when , It can be done by burn Function implementation to NFT Destruction of , It cannot be recovered after destruction .

6、SDK Access bottom chain

default Lighthouse There is no port required for open bottom chain access in environment , Without modifying the configuration 12301/12302/12303/12304. If you need to go through SDK Access bottom chain , You need to open the port first .

6.1、 Release the bottom chain access port

Enter Tencent cloud Lighthouse My management desk , Select the firewall page .

firewall

You can see that only some basic ports are open now , We are concerned about 12301-12304 Not open , Click here " Add rules " Button , Enter the rule configuration page ：

createRule

Fill in the rules according to the above figure , If you want to restrict access to sources , Which IP The address can access the port , You can choose Enable Check box , Fill in the specified source IP：

checkIP

After completion , Click the OK button , You will see the newly created rule ：

firewall-new

In this case, if it is used locally telnet Tools to access , You can find that the port has been accessed normally ：

telnet

6.2、 Download the certificate

adopt WebShell Sign in Lighthouse After the server , Use the following command to enter the user certificate page of the specified organization ：

[[email protected] ~]$ cd /home/chainmaker/chain/release/chainmaker-v2.2.1-lh-org1.chainmaker.org/config/lh-org1.chainmaker.org/certs/user
[[email protected] user]$ ll
total 12
drwxr-xr-x 2 chainmaker chainmaker 4096 Jun 14 11:31 admin1
drwxr-xr-x 2 chainmaker chainmaker 4096 Jun 14 11:31 client1
drwxr-xr-x 2 chainmaker chainmaker 4096 Jun 14 11:31 light1

Copy

The path in the above command chainmaker-v2.2.1-lh-org1.chainmaker.org and lh-org1.chainmaker.org Medium org1 The organization represented , Users can adjust according to their own organization , for example ：org2 The corresponding adjustment is ：

chainmaker-v2.2.1-lh-org2.chainmaker.org and lh-org2.chainmaker.org.

The system has built-in three users for each organization ：admin/client/light, They represent the administrator 、 Ordinary users and light node users .

Users can enter the designated user page to download the corresponding certificate according to their own needs , With admin For example ：

[[email protected] admin1]$ cd ../
[[email protected] user]$ cd admin1/
[[email protected] admin1]$ sudo su chainmaker
[[email protected] admin1]$ sz *
Received - admin1.sign.crt 17.89 KB/s Spend: 0 seconds
Received - admin1.sign.key  4.43 KB/s Spend: 0 seconds
Received - admin1.tls.crt 18.36 KB/s Spend: 0 seconds
Received - admin1.tls.key  4.52 KB/s Spend: 0 seconds

Copy

Special note , You need to switch to before downloading chainmaker user , Otherwise, there will be permission problems .

6.3、SDK Use

SDK Available for reference ：https://docs.chainmaker.org.cn/dev/SDK.html