Refactor code to handle case when API key is not provided

Dockerfile

@@ -1,32 +1,27 @@
-# Use the official Go image
-FROM golang:1.19 AS build
+# Use the official Golang image to create a build artifact.
+FROM golang:1.19 as builder
 
 # Set the working directory
 WORKDIR /app
 
-# Copy go mod and sum files
-COPY go.mod go.sum ./
+# Copy the Go Modules manifests
+COPY go.mod go.mod
+COPY go.sum go.sum
 
 # Download dependencies
 RUN go mod download
 
-# Copy source code
+# Copy the source code
 COPY . .
 
-# Build the application
-RUN go build -o main .
+# Build
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -o /app/main .
 
-# Use a lightweight image for deployment
-FROM alpine:latest AS runtime
+# Use a minimal image for deployment
+FROM alpine:latest
 
-# Install necessary libraries
-RUN apk --no-cache add ca-certificates
+# Copy the binary
+COPY --from=builder /app/main /app/main
 
-# Copy binary
-COPY --from=build /app/main /app/
-
-# Set the working directory
-WORKDIR /app
-
-# Run the application
-CMD [". --download-only"]
+# This is the entry point, specify your flags here
+ENTRYPOINT [ "/app/main", "--download-only" ]

config.go

@@ -14,6 +14,11 @@ type Config struct {
 }
 
 func getOrCreateAPIKey() string {
+	apiKey := os.Getenv("NASA_API_KEY")
+	if apiKey != "" {
+		return apiKey
+	}
+
 	filePathName := "Keys.json"
 	config, err := readConfig(filePathName)
 	if err != nil {
@@ -42,7 +47,7 @@ func getOrCreateAPIKey() string {
 		log.Fatalf("Error reading Keys.json: %v", err)
 	}
 
-	apiKey := config.APIKey
+	apiKey = config.APIKey
 	return apiKey
 }
 

main.go

@@ -22,7 +22,10 @@ type NasaAPOD struct {
 const apiURL = "https://api.nasa.gov/planetary/apod"
 
 func main() {
-	apiKey := getOrCreateAPIKey()
+	apiKey := os.Getenv("NASA_API_KEY")
+	if apiKey == "" {
+		apiKey = getOrCreateAPIKey()
+	}
 
 	start, end, downloadOnly := parseArgumentsForDateRange()