Graph REST API #116

api/graph.go

@@ -0,0 +1,56 @@
+package api
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"github.com/gin-gonic/gin"
+	"github.com/smira/aptly/graph"
+)
+
+// GET /api/graph
+func apiGraph(c *gin.Context) {
+	var (
+		err      error
+		output []byte
+	)
+
+	graph, err := graph.BuildGraph(context)
+	if err != nil {
+		c.JSON(500, err)
+		return
+	}
+
+	buf := bytes.NewBufferString(graph.String())
+
+	command := exec.Command("dot", "-Tpng")
+	command.Stderr = os.Stderr
+
+	stdin, err := command.StdinPipe()
+	if err != nil {
+		c.Fail(500, err)
+		return
+	}
+
+	_, err = io.Copy(stdin, buf)
+	if err != nil {
+		c.Fail(500, err)
+		return
+	}
+
+	err = stdin.Close()
+	if err != nil {
+		c.Fail(500, err)
+		return
+	}
+
+	output, err = command.Output()
+	if err != nil {
+		c.Fail(500, fmt.Errorf("unable to execute dot: %s (is graphviz package installed?)", err))
+		return
+	}
+
+	c.Data(200, "image/png", output)
+}