fix return 404 if state does not exist

Co-authored-by: Tobias Krischer <tobikris@users.noreply.github.com>

pkg/server/handler.go

@@ -2,6 +2,7 @@ package server
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -130,7 +131,11 @@ func Get(w http.ResponseWriter, r *http.Request, state *terraform.State, store s
 	log.Debugf("get state with id %s", state.ID)
 	stateID := state.ID
 	state, err := store.GetState(state.ID)
-	if err != nil {
+	if errors.Is(err, storage.ErrStateNotFound) {
+		log.Debugf("state with id %s does not exist", stateID)
+		HTTPResponse(w, r, http.StatusNotFound, err.Error())
+		return
+	} else if err != nil {
 		log.Warnf("failed to get state with id %s: %v", stateID, err)
 		HTTPResponse(w, r, http.StatusBadRequest, err.Error())
 		return

pkg/storage/filesystem/filesystem.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/nimbolus/terraform-backend/pkg/storage"
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
@@ -35,13 +36,7 @@ func (f *FileSystemStorage) SaveState(s *terraform.State) error {
 
 func (f *FileSystemStorage) GetState(id string) (*terraform.State, error) {
 	if _, err := os.Stat(f.getFileName(id)); errors.Is(err, os.ErrNotExist) {
-		f, err := os.Create(f.getFileName(id))
-		if err != nil {
-			return nil, err
-		}
-		defer f.Close()
-
-		return &terraform.State{}, nil
+		return nil, storage.ErrStateNotFound
 	}
 
 	d, err := os.ReadFile(f.getFileName(id))

pkg/storage/postgres/postgres.go

@@ -3,10 +3,12 @@ package postgres
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
 	"time"
 
 	pgclient "github.com/nimbolus/terraform-backend/pkg/client/postgres"
+	"github.com/nimbolus/terraform-backend/pkg/storage"
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
@@ -70,7 +72,9 @@ func (p *PostgresStorage) GetState(id string) (*terraform.State, error) {
 	s := &terraform.State{}
 
 	err := p.db.QueryRow(`SELECT state_data FROM `+p.table+` WHERE state_id = $1`, id).Scan(&s.Data)
-	if err != nil {
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, storage.ErrStateNotFound
+	} else if err != nil {
 		return nil, err
 	}
 

pkg/storage/s3/s3.go

@@ -8,6 +8,7 @@ import (
 	"github.com/minio/minio-go/v7"
 	"github.com/minio/minio-go/v7/pkg/credentials"
 
+	"github.com/nimbolus/terraform-backend/pkg/storage"
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
@@ -67,7 +68,7 @@ func (s *S3Storage) GetState(id string) (*terraform.State, error) {
 	buf := new(bytes.Buffer)
 	if _, err := buf.ReadFrom(obj); err != nil {
 		if minio.ToErrorResponse(err).Code == "NoSuchKey" {
-			return state, nil
+			return nil, storage.ErrStateNotFound
 		}
 		return state, err
 	}

pkg/storage/storage.go

@@ -1,9 +1,15 @@
 package storage
 
 import (
+	"errors"
+
 	"github.com/nimbolus/terraform-backend/pkg/terraform"
 )
 
+var (
+	ErrStateNotFound = errors.New("state does not exist")
+)
+
 type Storage interface {
 	GetName() string
 	SaveState(s *terraform.State) error

pkg/storage/util/storagetest.go

@@ -1,6 +1,7 @@
 package util
 
 import (
+	"errors"
 	"testing"
 
 	"github.com/spf13/viper"
@@ -21,6 +22,11 @@ func StorageTest(t *testing.T, s storage.Storage) {
 		Data:    []byte("test"),
 	}
 
+	nonExisting, err := s.GetState(state.ID)
+	if nonExisting != nil || !errors.Is(err, storage.ErrStateNotFound) {
+		t.Error("non existing state should return ErrStateNotFound")
+	}
+
 	if err := s.SaveState(state); err != nil {
 		t.Error(err)
 	}