go-graphviz 
Go bindings for Graphviz ( port of version 2.40.1 )
Features
- No need to install Graphviz library ( ~
brew install graphviz~ or ~apt-get install graphviz~ ) - Supports parsing for DOT language
- Supports rendering graph in pure Go
- Supports switch renderer to your own
- Supports type safed property setting
gvccgraphcdtare available as sub package
Currently supported Layout
circo dot fdp neato nop nop1 nop2 osage patchwork sfdp twopi
Currently supported format
dot svg png jpg
Installation
$ go get github.com/goccy/go-graphviz
Synopsis
1. Write DOT Graph in Go
package main
import (
"bytes"
"fmt"
"log"
"github.com/goccy/go-graphviz"
)
func main() {
g := graphviz.New()
graph, err := g.Graph()
if err != nil {
log.Fatal(err)
}
defer func() {
if err := graph.Close(); err != nil {
log.Fatal(err)
}
g.Close()
}()
n, err := graph.CreateNode("n")
if err != nil {
log.Fatal(err)
}
m, err := graph.CreateNode("m")
if err != nil {
log.Fatal(err)
}
e, err := graph.CreateEdge("e", n, m)
if err != nil {
log.Fatal(err)
}
e.SetLabel("e")
var buf bytes.Buffer
if err := g.Render(graph, "dot", &buf); err != nil {
log.Fatal(err)
}
fmt.Println(buf.String())
}
2. Parse DOT Graph
path := "/path/to/dot.gv"
b, err := ioutil.ReadFile(path)
if err != nil {
log.Fatal(err)
}
graph, err := graphviz.ParseBytes(b)
3. Render Graph
g := graphviz.New()
graph, err := g.Graph()
if err != nil {
log.Fatal(err)
}
// create your graph
// 1. write encoded PNG data to buffer
var buf bytes.Buffer
if err := g.Render(graph, graphviz.PNG, &buf); err != nil {
log.Fatal(err)
}
// 2. get as image.Image instance
image, err := g.RenderImage(graph)
if err != nil {
log.Fatal(err)
}
// 3. write to file directly
if err := g.RenderFilename(graph, graphviz.PNG, "/path/to/graph.png"); err != nil {
log.Fatal(err)
}
Tool
dot
Installation
$ go get github.com/goccy/go-graphviz/cmd/dot
Usage
Usage:
dot [OPTIONS]
Application Options:
-T= specify output format ( currently supported: dot svg png jpg ) (default: dot)
-K= specify layout engine ( currently supported: circo dot fdp neato nop nop1 nop2 osage patchwork sfdp twopi )
-o= specify output file name
Help Options:
-h, --help Show this help message
How it works
go-graphviz has four layers.
graphvizpackage provides facade interface for manipulating all features of graphviz librarygvccgraphcdtare sub packages ( FYI: C library section in https://www.graphviz.org/documentation )internal/ccallpackage provides bridge interface between Go and Cgo-graphvizincludes full graphviz sources
License
MIT