Files
mgmt/pgraph/graphviz.go
James Shubin 4de75373dd pgraph: Use pointers for unique vertex identifiers
This will build more accurate graphs, since we could have duplicated
vertex names for distinct vertices. This now builds the correct
topology, even if the labels are duplicated.
2019-04-29 16:08:36 -04:00

122 lines
3.4 KiB
Go

// Mgmt
// Copyright (C) 2013-2019+ James Shubin and the project contributors
// Written by James Shubin <james@shubin.ca> and the project contributors
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package pgraph // TODO: this should be a subpackage
import (
"fmt"
"io/ioutil"
"os"
"os/exec"
"strconv"
"syscall"
)
// Graphviz outputs the graph in graphviz format.
// https://en.wikipedia.org/wiki/DOT_%28graph_description_language%29
func (g *Graph) Graphviz() (out string) {
//digraph g {
// label="hello world";
// node [shape=box];
// A [label="A"];
// B [label="B"];
// C [label="C"];
// D [label="D"];
// E [label="E"];
// A -> B [label=f];
// B -> C [label=g];
// D -> E [label=h];
//}
out += fmt.Sprintf("digraph \"%s\" {\n", g.GetName())
out += fmt.Sprintf("\tlabel=\"%s\";\n", g.GetName())
//out += "\tnode [shape=box];\n"
str := ""
for i := range g.Adjacency() { // reverse paths
v1 := strconv.Quote(i.String()) // 1st vertex
out += fmt.Sprintf("\t\"%p\" [label=%s];\n", i, v1)
for j := range g.Adjacency()[i] {
k := g.Adjacency()[i][j]
//v2 := strconv.Quote(j.String()) // 2nd vertex
e := strconv.Quote(k.String()) // edge
// use str for clearer output ordering
//if fmtBoldFn(k) { // TODO: add this sort of formatting
// str += fmt.Sprintf("\t\"%s\" -> \"%s\" [label=\"%s\",style=bold];\n", i, j, k)
//} else {
str += fmt.Sprintf("\t\"%p\" -> \"%p\" [label=%s];\n", i, j, e)
//}
}
}
out += str
out += "}\n"
return
}
// ExecGraphviz writes out the graphviz data and runs the correct graphviz
// filter command.
func (g *Graph) ExecGraphviz(program, filename, hostname string) error {
switch program {
case "dot", "neato", "twopi", "circo", "fdp":
default:
return fmt.Errorf("invalid graphviz program selected")
}
if filename == "" {
return fmt.Errorf("no filename given")
}
if hostname != "" {
filename = fmt.Sprintf("%s@%s", filename, hostname)
}
// run as a normal user if possible when run with sudo
uid, err1 := strconv.Atoi(os.Getenv("SUDO_UID"))
gid, err2 := strconv.Atoi(os.Getenv("SUDO_GID"))
err := ioutil.WriteFile(filename, []byte(g.Graphviz()), 0644)
if err != nil {
return fmt.Errorf("error writing to filename")
}
if err1 == nil && err2 == nil {
if err := os.Chown(filename, uid, gid); err != nil {
return fmt.Errorf("error changing file owner")
}
}
path, err := exec.LookPath(program)
if err != nil {
return fmt.Errorf("the Graphviz program is missing")
}
out := fmt.Sprintf("%s.png", filename)
cmd := exec.Command(path, "-Tpng", fmt.Sprintf("-o%s", out), filename)
if err1 == nil && err2 == nil {
cmd.SysProcAttr = &syscall.SysProcAttr{}
cmd.SysProcAttr.Credential = &syscall.Credential{
Uid: uint32(uid),
Gid: uint32(gid),
}
}
_, err = cmd.Output()
if err != nil {
return fmt.Errorf("error writing to image")
}
return nil
}