aptly/api/graph.go

95 lines
2.4 KiB
Go

package api
import (
"bytes"
"fmt"
"io"
"mime"
"os"
"os/exec"
"github.com/aptly-dev/aptly/deb"
"github.com/gin-gonic/gin"
)
// @Summary Graph Output
// @Description **Generate dependency graph**
// @Description
// @Description Command graph generates graph of dependencies:
// @Description
// @Description * between snapshots and mirrors (what mirror was used to create each snapshot)
// @Description * between snapshots and local repos (what local repo was used to create snapshot)
// @Description * between snapshots (pulling, merging, etc.)
// @Description * between snapshots, local repos and published repositories (how snapshots were published).
// @Description
// @Description Graph is rendered to PNG file using graphviz package.
// @Description
// @Description Example URL: `http://localhost:8080/api/graph.svg?layout=vertical`
// @Tags Status
// @Produce image/png, image/svg+xml
// @Param ext path string true "ext specifies desired file extension, e.g. .png, .svg."
// @Param layout query string false "Change between a `horizontal` (default) and a `vertical` graph layout."
// @Success 200 {object} []byte "Output"
// @Failure 404 {object} Error "Not Found"
// @Failure 500 {object} Error "Internal Server Error"
// @Router /api/graph.{ext} [get]
func apiGraph(c *gin.Context) {
var (
err error
output []byte
)
ext := c.Params.ByName("ext")
layout := c.Request.URL.Query().Get("layout")
factory := context.NewCollectionFactory()
graph, err := deb.BuildGraph(factory, layout)
if err != nil {
c.JSON(500, err)
return
}
buf := bytes.NewBufferString(graph.String())
if ext == "dot" || ext == "gv" {
// If the raw dot data is requested, return it as string.
// This allows client-side rendering rather than server-side.
c.String(200, buf.String())
return
}
command := exec.Command("dot", "-T"+ext)
command.Stderr = os.Stderr
stdin, err := command.StdinPipe()
if err != nil {
AbortWithJSONError(c, 500, err)
return
}
_, err = io.Copy(stdin, buf)
if err != nil {
AbortWithJSONError(c, 500, err)
return
}
err = stdin.Close()
if err != nil {
AbortWithJSONError(c, 500, err)
return
}
output, err = command.Output()
if err != nil {
AbortWithJSONError(c, 500, fmt.Errorf("unable to execute dot: %s (is graphviz package installed?)", err))
return
}
mimeType := mime.TypeByExtension("." + ext)
if mimeType == "" {
mimeType = "application/octet-stream"
}
c.Data(200, mimeType, output)
}