00-svg-test.go

package main

// This is a demo application that uses the jujusvg library to build a bundle SVG
// from a given bundle.yaml file.

import (
	"io/ioutil"
	"log"
	"os"
	"strings"

	// Import the jujusvg library and the juju charm library
	"github.com/juju/jujusvg"
	"gopkg.in/juju/charm.v4"
)

// iconURL takes a reference to a charm and returns the URL for that charm's icon.
// In this case, we're using the manage.jujucharms.com API to provide the icon's URL.
func iconURL(ref *charm.Reference) string {
	return "https://manage.jujucharms.com/api/3/charm/" + ref.Path() + "/file/icon.svg"
}

func main() {
	// First, we need to read our bundle data into a []byte
	bundle_data, err := ioutil.ReadFile("bundle.yaml")
	if err != nil {
		log.Fatalf("Error reading bundle: %s\n", err)
	}

	// Next, generate a charm.Bundle from the bytearray by passing it to ReadNewBundleData.
	// This gives us an in-memory object representation of the bundle that we can pass to jujusvg
	bundle, err := charm.ReadBundleData(strings.NewReader(string(bundle_data)))
	if err != nil {
		log.Fatalf("Error parsing bundle: %s\n", err)
	}

	// Next, build a canvas of the bundle.  This is a simplified version of a charm.Bundle
	// that contains just the position information and charm icon URLs necessary to build
	// the SVG representation of the bundle
	canvas, err := jujusvg.NewFromBundle(bundle, iconURL)
	if err != nil {
		log.Fatalf("Error generating canvas: %s\n", err)
	}

	// Finally, marshal that canvas as SVG to os.Stdout; this will print the SVG data
	// required to generate an image of the bundle.
	canvas.Marshal(os.Stdout)
}

bundle.yaml

services:
  mongodb:
    charm: "cs:precise/mongodb-21"
    num_units: 1
    annotations:
      "gui-x": "940.5"
      "gui-y": "388.7698359714502"
    constraints: "mem=2G cpu-cores=1"
  elasticsearch:
    charm: "cs:~charming-devs/precise/elasticsearch-2"
    num_units: 1
    annotations:
      "gui-x": "490.5"
      "gui-y": "369.7698359714502"
    constraints: "mem=2G cpu-cores=1"
  charmworld:
    charm: "cs:~juju-jitsu/precise/charmworld-58"
    num_units: 1
    expose: true
    annotations:
      "gui-x": "813.5"
      "gui-y": "112.23016402854975"
    options:
      charm_import_limit: -1
      source: "lp:~bac/charmworld/ingest-local-charms"
      revno: 511
relations:
  - - "charmworld:essearch"
    - "elasticsearch:essearch"
  - - "charmworld:database"
    - "mongodb:database"
series: precise