FSC Node CLI Reference

Overview

FSC nodes are Go applications that embed the Fabric Smart Client library. You create a custom node application that registers your views (business logic) and starts the FSC node.

Creating a Node Application

FSC nodes require a Go application that embeds the FSC library:

package main

import (
    "fmt"
    
    fscnode "github.com/hyperledger-labs/fabric-smart-client/node"
    sdk "github.com/hyperledger-labs/fabric-smart-client/platform/view/sdk/dig"
)

func main() {
    node := fscnode.New()
    if err := node.InstallSDK(sdk.NewSDK(node)); err != nil {
        panic(err)
    }
    node.Execute(func() error {
        fmt.Println("Hello World")
        return nil
    })
}

Build your node:

go build -o mynode .

Commands

node start

Start the FSC node.

Usage:

./mynode node start

Description:

Starts the FSC node that:

• Loads configuration from core.yaml
• Initializes the View SDK
• Handles graceful shutdown on signals

Configuration Required:

The node requires a core.yaml file in:

• Current directory, OR
• Directory specified by FSCNODE_CFG_PATH environment variable

See Configuration Guide for complete configuration options.

Examples:

1. Start with default configuration:

# Looks for ./core.yaml
./mynode node start

2. Start with custom configuration path:

export FSCNODE_CFG_PATH=/etc/fsc
./mynode node start

3. Start with profiling enabled:

export FSCNODE_PROFILER=true
./mynode node start

4. Start in background:

nohup ./mynode node start > node.log 2>&1 &

version

Display version information.

Usage:

./mynode version

Output:

node:
 Go version: go1.21.0
 OS/Arch: darwin/arm64

Description:

• Shows program name
• Displays Go version used to build
• Shows OS and architecture

Environment Variables

All environment variables use the FSCNODE_ prefix.

FSCNODE_CFG_PATH

Description: Path to directory containing core.yaml

Type: String (directory path)

Default: ./ (current directory)

Example:

export FSCNODE_CFG_PATH=/etc/fsc
./mynode node start

FSCNODE_PROFILER

Description: Enable Go profiling for performance analysis

Type: Boolean (true or false)

Default: false

Example:

export FSCNODE_PROFILER=true
./mynode node start

When enabled, the following profiling data files are written to the configuration directory:

• cpu.pprof - CPU profiling data
• mem-heap.pprof - Memory heap profiling
• mem-allocs.pprof - Memory allocations profiling
• mutex.pprof - Mutex contention profiling
• block.pprof - Blocking profiling

These files can be analyzed using Go's pprof tool, for example:

go tool pprof cpu.pprof

Signal Handling

The FSC node handles these signals for graceful shutdown:

Signal	Behavior
SIGINT (Ctrl+C)	Graceful shutdown
SIGTERM	Graceful shutdown

Graceful shutdown:

1. Stop accepting new requests
2. Complete in-flight operations
3. Close connections
4. Exit cleanly

Note: The signal handling uses Go's signal.NotifyContext for cross-platform compatibility. On Unix-like systems, both SIGINT and SIGTERM trigger graceful shutdown. On Windows, Ctrl+C and Ctrl+Break are handled appropriately.

Exit Codes

Code	Meaning
0	Clean shutdown
1	Error during startup or operation