Совсем все починил.

Dockerfile

@@ -8,4 +8,5 @@ RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -installsuffix cgo -o prev
 FROM alpine:latest
 WORKDIR /
 COPY --from=builder /app/previewer .
+RUN mkdir -p /assets/cache
 CMD ["/previewer"]

Makefile

@@ -1,8 +1,5 @@
-docker-build:
-	sudo docker build -t previewer .
-
-build:
-	go build -o bin ./cmd/main.go
+lint: install-lint-deps
+	golangci-lint run ./previewer/... ./internal/...
 
 unit-test:
 	go test -race ./internal/...
@@ -10,8 +7,15 @@ unit-test:
 integration-test:
 	go test -v ./cmd/...
 
-lint: install-lint-deps
-	golangci-lint run ./previewer/... ./internal/...
+build:
+	go build -o bin ./cmd/main.go
+
+
+docker-build:
+	sudo docker build -t previewer .
+
+docker-run:
+	sudo docker run -p 8080:8080 previewer
 
 install-lint-deps:
 	rm -rf $(shell go env GOPATH)/bin/golangci-lint

internal/cache/cache.go

@@ -32,7 +32,11 @@ type Item struct {
 
 func NewCache(capacity int, path string) Cache {
 	if _, err := ioutil.ReadDir(path); err != nil {
-		log.Fatalf("cache directory %s not exists: %s", path, err.Error())
+		log.Printf("cache directory %s not exists. Try to create.\n", path)
+		err = os.MkdirAll(path, 0777)
+		if err != nil {
+			log.Fatalf("can't create cache directory %s: %s", path, err.Error())
+		}
 	}
 	return &lruCache{
 		capacity: capacity,

internal/config/config.go

@@ -49,7 +49,7 @@ func (c *Config) SetDefault() {
 	c.Cache = struct {
 		Capacity    int
 		StoragePath string
-	}{Capacity: 20, StoragePath: "../assets/cache"}
+	}{Capacity: 20, StoragePath: "./assets/cache"}
 	c.Query = struct{ Timeout int }{Timeout: 15}
 	c.Log = struct {
 		File       string

internal/logger/logger.go

@@ -38,7 +38,7 @@ func New(conf Config) (Interface, error) {
 
 	c := amitralog.Configuration{
 		EnableConsole:     !conf.MuteStdout,
-		ConsoleLevel:      amitralog.Fatal,
+		ConsoleLevel:      amitralog.Debug,
 		ConsoleJSONFormat: false,
 		EnableFile:        true,
 		FileLevel:         strings.ToLower(conf.Level),