如何在GCP云功能内加载本地资产？

Question

I'm building a tiny GCP cloud function in Golang that returns a generated PNG file when calling it via HTTP. I deployed my code via ZIP-Upload in the Google Cloud Console. Currently it gets called properly and the code gets compiled etc. But in my code I have to load several local files - a font and a .png image. I bundled those in the ZIP I uploaded and the files are visible in the Source-View in GCP. All files (images, fonts and go-files) are within the same directory.

When calling the cloud function the log states the following:

2019/01/21 14:59:31 open /english.png: no such file or directory

I tried to change the way i build the path to the file in go. I already used /german.png statically, used several attempts to build the path dynamically.

I'm not 100 percent sure if this is the way to go, but it is my first experiment with "serverless" and i am willing to get it done the "right" way.

import "github.com/fogleman/gg"


func main() {
    ex, err := os.Executable()
    if err != nil {
        panic(err)
    }
    executableDir := filepath.Dir(ex)

    img, err :=gg.LoadPNG(path.Join(executableDir, "./english.png"))
    if err != nil {
        log.Fatal(err)
    }
}

Currently the file can not be found in any attempt i made. Maybe the path the images get "deployed" into are different from the ones i tried - i have not found any note on that in the documentation. I'd obviously expect it to be loaded properly.

Answer 1

I created http functions with the following structure:

api
|--test.txt
|--api.go

And wrote simple function to reply with file content:

package api

import (
    "io/ioutil"
    "net/http"
)

// FileTest func
func FileTest(w http.ResponseWriter, r *http.Request) {
    content, err := ioutil.ReadFile("./test.txt")
    if err != nil {
        w.WriteHeader(http.StatusInternalServerError)
        w.Write([]byte(err.Error()))
        return
    }

    w.Write(content)
}

It returns the file content without any problems. https://us-central1-clickshield24m.cloudfunctions.net/api

So in your case I would try change the path to gg.LoadPNG("./english.png")