为什么docker在docker容器中找不到JSON文件的Env变量？

Question

当我想添加一个带有 JSON 文件路径的环境变量作为GOOGLE_APPLICATION_CREDENTIALS凭据时遇到问题

我的文件系统是这样的：

Dockerfile
-app
   main.go
   -domain
     go files inside domain folder
   -repositories
     go files inside repositories folder
     firebase-services.json file credentials inside repositories folder
-ui
  html, css, js & images inside ui folder

我的dockerfile是

FROM golang:alpine

# Set necessary environmet variables needed for our image
ENV GO111MODULE=on \
    CGO_ENABLED=0 \
    GOOS=linux \
    GOARCH=amd64 \
    GIN_MODE=release \
    GOOGLE_APPLICATION_CREDENTIALS='/build/app/repositories/firebase-services.json'

# Copy the code into the container
COPY ui /ui/

# Move to working directory /build
WORKDIR /build

# Copy the code from /app to the build folder into the container
COPY app .

# Configure the build (go.mod and go.sum are already copied with prior step)
RUN go mod download

# Build the application
RUN go build -o main .

WORKDIR /app

# Copy binary from build to main folder
RUN cp /build/main .

# Export necessary port
EXPOSE 8000

# Command to run when starting the container
CMD ["/app/main"]

我尝试了GOOGLE_APPLICATION_CREDENTIALS所有内容，放置了相对路径、完整路径（在我的电脑中）、我正在创建的构建文件夹......但是当我运行容器时，总是得到Failed to create client: dialing: google: error getting credentials using GOOGLE_APPLICATION_CREDENTIALS environment variable: open /build/app/repositories/firebase-services.json: not a directory的答案Failed to create client: dialing: google: error getting credentials using GOOGLE_APPLICATION_CREDENTIALS environment variable: open /build/app/repositories/firebase-services.json: not a directory

我缺少什么？ 路径应该是什么？