Merge pull request #270 from sosedoff/data-export

Database export

pkg/api/api.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	neturl "net/url"
+	"strings"
 	"time"
 
 	"github.com/gin-gonic/gin"
@@ -398,3 +399,32 @@ func GetInfo(c *gin.Context) {
 
 	c.JSON(200, info)
 }
+
+// Export database or table data
+func DataExport(c *gin.Context) {
+	db := DB(c)
+
+	info, err := db.Info()
+	if err != nil {
+		c.JSON(400, Error{err.Error()})
+		return
+	}
+
+	dump := client.Dump{
+		Table: strings.TrimSpace(c.Request.FormValue("table")),
+	}
+
+	formattedInfo := info.Format()[0]
+	filename := formattedInfo["current_database"].(string)
+	if dump.Table != "" {
+		filename = filename + "_" + dump.Table
+	}
+
+	attachment := fmt.Sprintf(`attachment; filename="%s.sql.gz"`, filename)
+	c.Header("Content-Disposition", attachment)
+
+	err = dump.Export(db.ConnectionString, c.Writer)
+	if err != nil {
+		c.JSON(400, Error{err.Error()})
+	}
+}

pkg/api/routes.go

@@ -47,5 +47,6 @@ func SetupRoutes(router *gin.Engine) {
 		api.POST("/explain", ExplainQuery)
 		api.GET("/history", GetHistory)
 		api.GET("/bookmarks", GetBookmarks)
+		api.GET("/export", DataExport)
 	}
 }

pkg/client/dump.go

@@ -0,0 +1,37 @@
+package client
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os/exec"
+)
+
+type Dump struct {
+	Table string
+}
+
+func (d *Dump) Export(url string, writer io.Writer) error {
+	errOutput := bytes.NewBuffer(nil)
+
+	opts := []string{
+		"--no-owner",      // skip restoration of object ownership in plain-text format
+		"--clean",         // clean (drop) database objects before recreating
+		"--compress", "6", // compression level for compressed formats
+	}
+
+	if d.Table != "" {
+		opts = append(opts, []string{"--table", d.Table}...)
+	}
+
+	opts = append(opts, url)
+
+	cmd := exec.Command("pg_dump", opts...)
+	cmd.Stdout = writer
+	cmd.Stderr = errOutput
+
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("error: %s. output: %s", err.Error(), errOutput.Bytes())
+	}
+	return nil
+}