store: make state (de)serialization internal

This hides the state hanlding in the store package. As before, it
can be disabled by passing `nil` instead of the path to the state
file.

Signed-off-by: Tom Gundersen <teg@jklm.no>

cmd/osbuild-composer/main.go

@@ -2,10 +2,8 @@ package main
 
 import (
 	"flag"
-	"io/ioutil"
 	"log"
 	"os"
-	"path/filepath"
 
 	"osbuild-composer/internal/jobqueue"
 	"osbuild-composer/internal/rpmmd"
@@ -15,13 +13,13 @@ import (
 	"github.com/coreos/go-systemd/activation"
 )
 
-const StateFile = "/var/lib/osbuild-composer/state.json"
-
 func main() {
 	var verbose bool
 	flag.BoolVar(&verbose, "v", false, "Print access log")
 	flag.Parse()
 
+	stateFile := "/var/lib/osbuild-composer/state.json"
+
 	listeners, err := activation.Listeners()
 	if err != nil {
 		panic(err)
@@ -55,60 +53,11 @@ func main() {
 		panic(err)
 	}
 
-	state, err := ioutil.ReadFile(StateFile)
-	if err != nil && !os.IsNotExist(err) {
-		log.Fatalf("cannot read state: %v", err)
-	}
-
-	stateChannel := make(chan []byte, 10)
-
-	store := store.New(state, stateChannel)
+	store := store.New(&stateFile)
 
 	jobAPI := jobqueue.New(logger, store)
 	weldrAPI := weldr.New(repo, packages, logger, store)
-	go func() {
-		for {
-			err := writeFileAtomically(StateFile, <-stateChannel, 0755)
-			if err != nil {
-				log.Fatalf("cannot write state: %v", err)
-			}
-		}
-	}()
 
 	go jobAPI.Serve(jobListener)
 	weldrAPI.Serve(weldrListener)
 }
-
-func writeFileAtomically(filename string, data []byte, mode os.FileMode) error {
-	dir, name := filepath.Dir(filename), filepath.Base(filename)
-
-	tmpfile, err := ioutil.TempFile(dir, name+"-*.tmp")
-	if err != nil {
-		return err
-	}
-
-	_, err = tmpfile.Write(data)
-	if err != nil {
-		os.Remove(tmpfile.Name())
-		return err
-	}
-
-	err = tmpfile.Chmod(mode)
-	if err != nil {
-		return err
-	}
-
-	err = tmpfile.Close()
-	if err != nil {
-		os.Remove(tmpfile.Name())
-		return err
-	}
-
-	err = os.Rename(tmpfile.Name(), filename)
-	if err != nil {
-		os.Remove(tmpfile.Name())
-		return err
-	}
-
-	return nil
-}

internal/jobqueue/api_test.go

@@ -88,7 +88,7 @@ func TestBasic(t *testing.T) {
 		//{"PATCH", "/job-queue/v1/jobs/ffffffff-ffff-ffff-ffff-ffffffffffff", `{"status":"FINISHED"}`, http.StatusNotAllowed, ``},
 	}
 
-	store := store.New(nil, nil)
+	store := store.New(nil)
 	api := jobqueue.New(nil, store)
 	for _, c := range cases {
 		id, _ := uuid.Parse("ffffffff-ffff-ffff-ffff-ffffffffffff")

internal/store/store.go

@@ -5,11 +5,13 @@ package store
 import (
 	"encoding/json"
 	"errors"
+	"io/ioutil"
 	"log"
 	"os"
 	"osbuild-composer/internal/blueprint"
 	"osbuild-composer/internal/job"
 	"osbuild-composer/internal/target"
+	"path/filepath"
 	"sort"
 	"sync"
 	"time"
@@ -26,7 +28,7 @@ type Store struct {
 
 	mu           sync.RWMutex // protects all fields
 	pendingJobs  chan job.Job
-	stateChannel chan<- []byte
+	stateChannel chan []byte
 }
 
 // A Compose represent the task of building one image. It contains all the information
@@ -48,14 +50,30 @@ type Image struct {
 	Mime string
 }
 
-func New(initialState []byte, stateChannel chan<- []byte) *Store {
+func New(stateFile *string) *Store {
 	var s Store
 
-	if initialState != nil {
-		err := json.Unmarshal(initialState, &s)
-		if err != nil {
-			log.Fatalf("invalid initial state: %v", err)
+	if stateFile != nil {
+		state, err := ioutil.ReadFile(*stateFile)
+		if state != nil {
+			err := json.Unmarshal(state, &s)
+			if err != nil {
+				log.Fatalf("invalid initial state: %v", err)
+			}
+		} else if !os.IsNotExist(err) {
+			log.Fatalf("cannot read state: %v", err)
 		}
+
+		s.stateChannel = make(chan []byte, 128)
+
+		go func() {
+			for {
+				err := writeFileAtomically(*stateFile, <-s.stateChannel, 0755)
+				if err != nil {
+					log.Fatalf("cannot write state: %v", err)
+				}
+			}
+		}()
 	}
 
 	if s.Blueprints == nil {
@@ -68,12 +86,45 @@ func New(initialState []byte, stateChannel chan<- []byte) *Store {
 		// TODO: push waiting/running composes to workers again
 		s.Composes = make(map[uuid.UUID]Compose)
 	}
-	s.stateChannel = stateChannel
 	s.pendingJobs = make(chan job.Job, 200)
 
 	return &s
 }
 
+func writeFileAtomically(filename string, data []byte, mode os.FileMode) error {
+	dir, name := filepath.Dir(filename), filepath.Base(filename)
+
+	tmpfile, err := ioutil.TempFile(dir, name+"-*.tmp")
+	if err != nil {
+		return err
+	}
+
+	_, err = tmpfile.Write(data)
+	if err != nil {
+		os.Remove(tmpfile.Name())
+		return err
+	}
+
+	err = tmpfile.Chmod(mode)
+	if err != nil {
+		return err
+	}
+
+	err = tmpfile.Close()
+	if err != nil {
+		os.Remove(tmpfile.Name())
+		return err
+	}
+
+	err = os.Rename(tmpfile.Name(), filename)
+	if err != nil {
+		os.Remove(tmpfile.Name())
+		return err
+	}
+
+	return nil
+}
+
 func (s *Store) change(f func()) {
 	s.mu.Lock()
 	defer s.mu.Unlock()

internal/weldr/api_test.go

@@ -153,13 +153,13 @@ func TestBasic(t *testing.T) {
 	}
 
 	for _, c := range cases {
-		api := weldr.New(repo, packages, nil, store.New(nil, nil))
+		api := weldr.New(repo, packages, nil, store.New(nil))
 		testRoute(t, api, "GET", c.Path, ``, c.ExpectedStatus, c.ExpectedJSON)
 	}
 }
 
 func TestBlueprints(t *testing.T) {
-	api := weldr.New(repo, packages, nil, store.New(nil, nil))
+	api := weldr.New(repo, packages, nil, store.New(nil))
 
 	testRoute(t, api, "POST", "/api/v0/blueprints/new",
 		`{"name":"test","description":"Test","packages":[{"name":"httpd","version":"2.4.*"}],"version":"0.0.0"}`,
@@ -182,7 +182,7 @@ func TestBlueprints(t *testing.T) {
 }
 
 func TestCompose(t *testing.T) {
-	api := weldr.New(repo, packages, nil, store.New(nil, nil))
+	api := weldr.New(repo, packages, nil, store.New(nil))
 
 	testRoute(t, api, "POST", "/api/v0/blueprints/new",
 		`{"name":"test","description":"Test","packages":[{"name":"httpd","version":"2.4.*"}],"version":"0.0.0"}`,