我已經按照在本地完美運行的 youtube 教程創建了一個簡單的 API。將應用程序容器化并運行容器后，我無法訪問 http://localhost:8080 上的 API。我猜它與我在 dockerfile 中使用的端口設置有關，但我不確定。main.go 文件：package mainimport (    "net/http"    "github.com/gin-gonic/gin"    "errors")type phone struct{    ID       string `json:"id"`    Model    string `json:"model"`    Year     string `json:"year"`    Quantity int    `json:"quantity"`}var phones = []phone{    {ID: "1", Model: "iPhone 11", Year: "2019", Quantity: 4},    {ID: "2", Model: "iPhone 6", Year: "2014", Quantity: 9},    {ID: "3", Model: "iPhone X", Year: "2017", Quantity: 2},}func phoneById(c *gin.Context) {    id := c.Param("id")    phone, err := getPhoneById(id)    if err != nil {        c.IndentedJSON(http.StatusNotFound, gin.H{"message": "Phone not found."})        return    }    c.IndentedJSON(http.StatusOK, phone)}func checkoutPhone(c *gin.Context) {    id, ok := c.GetQuery("id")    if !ok {        c.IndentedJSON(http.StatusBadRequest, gin.H{"Message": "Missing id query paramater"})        return    }    phone, err := getPhoneById(id)    if err != nil {        c.IndentedJSON(http.StatusBadRequest, gin.H{"Message": "Phone not found"})        return    }    if phone.Quantity <= 0 {        c.IndentedJSON(http.StatusBadRequest, gin.H{"Message": "Phone not available."})        return    }    phone.Quantity -= 1    c.IndentedJSON(http.StatusOK, phone)}func returnPhone(c *gin.Context) {    id, ok := c.GetQuery("id")    if !ok {        c.IndentedJSON(http.StatusBadRequest, gin.H{"Message": "Missing id query paramater"})        return    }    phone, err := getPhoneById(id)    if err != nil {        c.IndentedJSON(http.StatusBadRequest, gin.H{"Message": "Phone not found"})        return    }    if phone.Quantity <= 0 {        c.IndentedJSON(http.StatusBadRequest, gin.H{"Message": "Phone not available."})        return    }    phone.Quantity += 1    c.IndentedJSON(http.StatusOK, phone)}