cmds to handle signal traps correctly #161

The providers now have a clean up that needs to happen before the
binary exits. This is handle by trapping terminal signals and running
the clean up routines. The initial way we were doing this was not
correct.

atlas/atlas.go

@@ -48,7 +48,7 @@ func (a *Atlas) AllMaps() []Map {
 
 //	SeedMapTile will generate a tile and persist it to the
 //	configured cache backend
-func (a *Atlas) SeedMapTile(m Map, z, x, y uint64) error {
+func (a *Atlas) SeedMapTile(ctx context.Context, m Map, z, x, y uint64) error {
 	//	confirm we have a cache backend
 	if a.cacher == nil {
 		return ErrMissingCache
@@ -57,7 +57,7 @@ func (a *Atlas) SeedMapTile(m Map, z, x, y uint64) error {
 	tile := slippy.NewTile(z, x, y, float64(m.TileBuffer), m.SRID)
 
 	//	encode the tile
-	b, err := m.Encode(context.Background(), tile)
+	b, err := m.Encode(ctx, tile)
 	if err != nil {
 		return err
 	}
@@ -159,8 +159,8 @@ func SetCache(c cache.Interface) {
 
 //	SeedMapTile will generate a tile and persist it to the
 //	configured cache backend for the DefaultAtlas
-func SeedMapTile(m Map, z, x, y uint64) error {
-	return DefaultAtlas.SeedMapTile(m, z, x, y)
+func SeedMapTile(ctx context.Context, m Map, z, x, y uint64) error {
+	return DefaultAtlas.SeedMapTile(ctx, m, z, x, y)
 }
 
 //	PurgeMapTile will purge a map tile from the configured cache backend

cmd/tegola/cmd/cache.go

@@ -1,8 +1,8 @@
 package cmd
 
 import (
+	"context"
 	"fmt"
-	"log"
 	"runtime"
 	"strconv"
 	"strings"
@@ -11,10 +11,14 @@ import (
 
 	"github.com/spf13/cobra"
 
+	gdcmd "github.com/gdey/cmd"
+
 	"github.com/terranodo/tegola"
 	"github.com/terranodo/tegola/atlas"
 	"github.com/terranodo/tegola/cache"
+	"github.com/terranodo/tegola/internal/log"
 	"github.com/terranodo/tegola/maths/webmercator"
+	"github.com/terranodo/tegola/provider"
 )
 
 var (
@@ -56,6 +60,8 @@ var cacheCmd = &cobra.Command{
 		return nil
 	},
 	Run: func(cmd *cobra.Command, args []string) {
+		defer gdcmd.New().Complete()
+		gdcmd.OnComplete(provider.Cleanup)
 		var err error
 		var maps []atlas.Map
 
@@ -157,8 +163,16 @@ var cacheCmd = &cobra.Command{
 		for i := 0; i < cacheConcurrency; i++ {
 			//	spin off a worker listening on a channel
 			go func(tiler chan MapTile) {
+				ctx, cancel := context.WithCancel(context.Background())
+				go func() {
+					<-gdcmd.Cancelled()
+					cancel()
+				}()
 				//	range our channel to listen for jobs
 				for mt := range tiler {
+					if gdcmd.IsCancelled() {
+						continue
+					}
 					//	we will only have a single command arg so we can switch on index 0
 					switch args[0] {
 					case "seed":
@@ -197,7 +211,7 @@ var cacheCmd = &cobra.Command{
 							}
 							//	if we have a cache hit, then skip processing this tile
 							if hit {
-								log.Printf("cache seed set to not overwrite existing tiles. skipping map (%v) tile (%v/%v/%v)", mt.MapName, mt.Tile.Z, mt.Tile.X, mt.Tile.Y)
+								log.Infof("cache seed set to not overwrite existing tiles. skipping map (%v) tile (%v/%v/%v)", mt.MapName, mt.Tile.Z, mt.Tile.X, mt.Tile.Y)
 								continue
 							}
 						}
@@ -208,18 +222,19 @@ var cacheCmd = &cobra.Command{
 						}
 
 						//	seed the tile
-						if err = atlas.SeedMapTile(m, uint64(mt.Tile.Z), uint64(mt.Tile.X), uint64(mt.Tile.Y)); err != nil {
-							log.Fatalf("error seeding tile (%+v): %v", mt.Tile, err)
+						if err = atlas.SeedMapTile(ctx, m, uint64(mt.Tile.Z), uint64(mt.Tile.X), uint64(mt.Tile.Y)); err != nil {
+							log.Errorf("error seeding tile (%+v): %v", mt.Tile, err)
+							break
 						}
 
 						//	TODO: this is a hack to get around large arrays not being garbage collected
 						//	https://github.com/golang/go/issues/14045 - should be addressed in Go 1.11
 						runtime.GC()
 
-						log.Printf("seeding map (%v) tile (%v/%v/%v) took: %v", mt.MapName, mt.Tile.Z, mt.Tile.X, mt.Tile.Y, time.Now().Sub(t))
+						log.Infof("seeding map (%v) tile (%v/%v/%v) took: %v", mt.MapName, mt.Tile.Z, mt.Tile.X, mt.Tile.Y, time.Now().Sub(t))
 
 					case "purge":
-						log.Printf("purging map (%v) tile (%v/%v/%v)", mt.MapName, mt.Tile.Z, mt.Tile.X, mt.Tile.Y)
+						log.Infof("purging map (%v) tile (%v/%v/%v)", mt.MapName, mt.Tile.Z, mt.Tile.X, mt.Tile.Y)
 
 						//	lookup the Map
 						m, err := atlas.GetMap(mt.MapName)
@@ -229,7 +244,8 @@ var cacheCmd = &cobra.Command{
 
 						//	purge the tile
 						if err = atlas.PurgeMapTile(m, mt.Tile); err != nil {
-							log.Fatalf("error purging tile (%+v): %v", mt.Tile, err)
+							log.Errorf("error purging tile (%+v): %v", mt.Tile, err)
+							break
 						}
 					}
 				}
@@ -238,8 +254,8 @@ var cacheCmd = &cobra.Command{
 				wg.Done()
 			}(tiler)
 		}
-
 		//	iterate our zoom range
+	ZoomLoop:
 		for i := range zooms {
 
 			topLeft := *tegola.NewTileLatLong(zooms[i], bounds[1], bounds[0])
@@ -258,8 +274,13 @@ var cacheCmd = &cobra.Command{
 							MapName: maps[m].Name,
 							Tile:    tegola.NewTile(zooms[i], x, y),
 						}
+						select {
+						case tiler <- mapTile:
+						case <-gdcmd.Cancelled():
+							log.Info("cancel recieved; cleaning up…")
+							break ZoomLoop
+						}
 
-						tiler <- mapTile
 					}
 				}
 			}

cmd/tegola/cmd/root.go

@@ -71,9 +71,6 @@ func initConfig() {
 		log.Fatal(err)
 	}
 
-	// setup provider tear down.
-	setupTrap()
-
 	// init our providers
 	providers, err := initProviders(conf.Providers)
 	if err != nil {

cmd/tegola/cmd/server.go

@@ -1,7 +1,12 @@
 package cmd
 
 import (
+	"context"
+	"time"
+
+	gdcmd "github.com/gdey/cmd"
 	"github.com/spf13/cobra"
+	"github.com/terranodo/tegola/provider"
 	"github.com/terranodo/tegola/server"
 )
 
@@ -15,7 +20,9 @@ var serverCmd = &cobra.Command{
 	Short: "Use tegola as a tile server",
 	Long:  `Use tegola as a vector tile server. Maps tiles will be served at /maps/:map_name/:z/:x/:y`,
 	Run: func(cmd *cobra.Command, args []string) {
+		gdcmd.New()
 		initConfig()
+		gdcmd.OnComplete(provider.Cleanup)
 
 		//	check config for server port setting
 		//	if you set the port via the comand line it will override the port setting in the config
@@ -38,6 +45,14 @@ var serverCmd = &cobra.Command{
 		}
 
 		//	start our webserver
-		server.Start(serverPort)
+		srv := server.Start(serverPort)
+		gdcmd.OnComplete(func() {
+			ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
+			defer cancel() // releases resources if slowOperation completes before timeout elapses
+			srv.Shutdown(ctx)
+		})
+		<-gdcmd.Cancelled()
+		gdcmd.Complete()
+
 	},
 }

cmd/xyz2svg/cmd/draw.go

@@ -131,6 +131,7 @@ func drawCommand(cmd *cobra.Command, args []string) {
 			panic(err)
 		}
 	}
+	provider.Cleanup()
 }
 
 func drawFeatures(pname string, tiler provider.Tiler, layers []string, gid int, dfn *drawFilename) error {

cmd/xyz2svg/cmd/root.go

@@ -48,7 +48,6 @@ func init() {
 func initProviders(providers []map[string]interface{}) (prvs map[string]provider.Tiler, err error) {
 
 	prvs = make(map[string]provider.Tiler)
-	setupTrap()
 
 	// iterate providers
 	for _, p := range providers {

provider/provider.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/terranodo/tegola/geom"
+	"github.com/terranodo/tegola/internal/log"
 )
 
 type Tile interface {
@@ -91,6 +92,7 @@ func For(name string, config map[string]interface{}) (Tiler, error) {
 }
 
 func Cleanup() {
+	log.Info("cleaning up providers")
 	for _, p := range providers {
 		if p.cleanup != nil {
 			p.cleanup()

server/server.go

@@ -35,7 +35,7 @@ var (
 )
 
 //	Start starts the tile server binding to the provided port
-func Start(port string) {
+func Start(port string) *http.Server {
 	Atlas = atlas.DefaultAtlas
 
 	//	notify the user the server is starting
@@ -64,7 +64,9 @@ func Start(port string) {
 	group.UsingContext().Handler("GET", "/*path", http.FileServer(assetFS()))
 
 	//	start our server
-	log.Fatal(http.ListenAndServe(port, r))
+	srv := &http.Server{Addr: port, Handler: r}
+	go func() { log.Error(srv.ListenAndServe()) }()
+	return srv
 }
 
 //	determines the hostname:port to return based on the following hierarchy