c0c01612e9
This PR significantly changes the APIs for instantiating Ethereum nodes in a Go program. The new APIs are not backwards-compatible, but we feel that this is made up for by the much simpler way of registering services on node.Node. You can find more information and rationale in the design document: https://gist.github.com/renaynay/5bec2de19fde66f4d04c535fd24f0775. There is also a new feature in Node's Go API: it is now possible to register arbitrary handlers on the user-facing HTTP server. In geth, this facility is used to enable GraphQL. There is a single minor change relevant for geth users in this PR: The GraphQL API is no longer available separately from the JSON-RPC HTTP server. If you want GraphQL, you need to enable it using the ./geth --http --graphql flag combination. The --graphql.port and --graphql.addr flags are no longer available.
60 lines
2.1 KiB
Go
60 lines
2.1 KiB
Go
// Copyright 2015 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package node_test
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import (
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"fmt"
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"log"
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"github.com/ethereum/go-ethereum/node"
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)
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// SampleLifecycle is a trivial network service that can be attached to a node for
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// life cycle management.
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//
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// The following methods are needed to implement a node.Lifecycle:
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// - Start() error - method invoked when the node is ready to start the service
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// - Stop() error - method invoked when the node terminates the service
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type SampleLifecycle struct{}
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func (s *SampleLifecycle) Start() error { fmt.Println("Service starting..."); return nil }
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func (s *SampleLifecycle) Stop() error { fmt.Println("Service stopping..."); return nil }
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func ExampleLifecycle() {
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// Create a network node to run protocols with the default values.
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stack, err := node.New(&node.Config{})
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if err != nil {
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log.Fatalf("Failed to create network node: %v", err)
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}
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defer stack.Close()
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// Create and register a simple network Lifecycle.
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service := new(SampleLifecycle)
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stack.RegisterLifecycle(service)
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// Boot up the entire protocol stack, do a restart and terminate
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if err := stack.Start(); err != nil {
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log.Fatalf("Failed to start the protocol stack: %v", err)
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}
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if err := stack.Close(); err != nil {
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log.Fatalf("Failed to stop the protocol stack: %v", err)
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}
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// Output:
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// Service starting...
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// Service stopping...
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}
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