@hyperledger/cactus-api-client
Summary
The Hyperledger Cactus API Client package is designed to be a generic extension with convenience features wrapped around the
[typescript-axios flavored API clients](https://github.com/OpenAPITools/openapi-generator/blob/v5.2.1/docs/generators/typescript-axios.md) that we auto-generate and ship with each web service-enabled
plugin such as the API clients of the
The code generation for the listed code folders above is done by the OpenAPI Generator tool that can convert OpenAPI V3 json specifications of ours straight into the program code of the API clients.
The above means that the ApiClient
class is not the one containing the implementation
responsible for executing all the supported API calls by a Cactus node (which would make
it a monolith, something that we try to avoid as it is the opposite of a flexible plugin
architecture)
For example you can use the @hyperledger/cactus-api-client
node package to perform
Cactus node discovery based on ledger IDs (that can be obtained from the ConsortiumDatabase
as defined by the generated models of the @hyperledger/cactus-core-api
package.
While you can generate API Clients for the Cactus API specifications in any supported langauge of the OpenAPI Generator the features provided by this package will have to be developed separately (if not already done by the Cactus maintainers).
Currently the only implementation of the abstract API Client and its features (node discovery) is in Typescript (e.g. the @hyperledger/cactus-api-client
package).
Usage
Routing to Cactus Node with connector to specific ledger
Let's say you have a consortium with several members who all have their own ledgers deployed as well.
The ConsortiumDatabase
will therefore contain the entities pertaining to these entities
(such as the ledgers or the members themselves) meaning that if you are developing an
application that needs to perform operations on one of the ledgers in the consortium then
you have a couple of different ways of obtaining an API client to do just that:
Leverage the ConsortiumDatabase
for discovery
import { ApiClient } from "@hyperledger/cactus-api-client";
import { ConsortiumDatabase, Ledger, LedgerType } from "@hyperledger/cactus-core-api";
import { PluginRegistry } from "@hyperledger/cactus-core";
import { DefaultApi as QuorumApi } from "@hyperledger/cactus-plugin-ledger-connector-quorum";
const mainFn = async () => {
const ledgerId = "theIdOfYourLedgerInTheConsortiumDatabase";
const consortiumProvider: IAsyncProvider<ConsortiumDatabase> = ...;
const consortiumDatabase: ConsortiumDatabase = await consortiumProvider.get();
const consortium = consortiumDatabase.consortium[0];
const mainApiClient = new ApiClient({ basePath: consortium.mainApiHost });
const apiClient = await mainApiClient.ofLedger(ledgerId, QuorumApi);
};
mainFn();
Use a provided mainApiHost
and ledgerId
import { ApiClient } from "@hyperledger/cactus-api-client";
import { ConsortiumDatabase, Ledger, LedgerType } from "@hyperledger/cactus-core-api";
import { PluginRegistry } from "@hyperledger/cactus-core";
import { DefaultApi as QuorumApi } from "@hyperledger/cactus-plugin-ledger-connector-quorum";
const mainFn = async () => {
const ledgerId = "theIdOfYourLedgerInTheConsortiumDatabase";
const consortiumMainApiHost = "https://cactus.example.com";
const mainApiClient = new ApiClient({ basePath: consortiumMainApiHost });
const apiClient = await mainApiClient.ofLedger(ledgerId, QuorumApi);
}
mainFn();
Use the API host of a node directly
import { ApiClient } from "@hyperledger/cactus-api-client";
import { ConsortiumDatabase, Ledger, LedgerType } from "@hyperledger/cactus-core-api";
import { PluginRegistry } from "@hyperledger/cactus-core";
import { DefaultApi as QuorumApi } from "@hyperledger/cactus-plugin-ledger-connector-quorum";
const mainFn = async () => {
const nodeApiHost = "https://my-node.cactus.example.com";
const mainApiClient = new ApiClient({ basePath: nodeApiHost });
const apiClient = await mainApiClient.extendWith(QuorumApi);
}
mainFn();
Public API Surface
DefaultConsortiumProvider
Builds the default Consortium provider that can be used by this object to retrieve the Cactus Consortium metadata object when necessary (one such case is when we need information about the consortium nodes to perform routing requests to a specific ledger via a connector plugin, but later other uses could be added as well).
The DefaultConsortiumProvider class leverages the simplest consortium plugin that we have at the time of this writing: @hyperledger/cactus-plugin-consortium-manual which holds the consortium metadata as pre-configured by the consortium operators.
The pattern we use in the ApiClient class is that you can inject your own IAsyncProvider<Consortium>
implementation which then will be used for routing information and in theory you can implement completely arbitrary consortium management in your own consortium plugins which then Cactus can use and leverage for the routing. This allows us to support any exotic consortium management algorithms that people may come up with such as storing the consortium definition in a multi-sig smart contract or have the list of consortium nodes be powered by some sort of automatic service discovery or anything else that people might think of.
ApiClient
Class responsible for providing additional functionality to the DefaultApi classes of the generated clients (OpenAPI generator / typescript-axios).
Each package (plugin) can define it's own OpenAPI spec which means that they all can ship with their own DefaultApi
class that is generated directly from the respective OpenAPI spec of the package/plugin.
The functionality provided by this class is meant to be common traints that can be useful for all of those different DefaultApi
implementations.
One such common trait is the client side component of the routing that decides which Cactus node to point the ApiClient
towards (which is in itself ends up being the act of routing).
@see — https ://github.com/OpenAPITools/openapi-generator/blob/v5.0.0-beta2/modules/openapi-generator/src/main/resources/typescript-axios/apiInner.mustache#L337
@see — https ://github.com/OpenAPITools/openapi-generator/blob/v5.0.0/docs/generators/typescript-axios.md