Sending GET requests from user input within Docker? - docker

Question

I'm using Golang and trying to take user input from the CLI and send it as a GET request to localhost:8080 but I can't work out how to do it. I currently have the following and am using a Docker container:
func main() {
fmt.Println("Enter desired input: ")
// Get user input
var input string
fmt.Scanln(&input)
http.HandleFunc("/", doSomething)
log.Fatal(http.ListenAndServe(":8081", nil))
resp, err := http.Get("http://localhost:8080/?input=" + input)
// Print response out here
}
func doSomething(w http.ResponseWriter, r *http.Request) {
query := r.URL.Query().Get("input")
// Send response
}
Docker file:
FROM golang:1.12.0-alpine3.9
RUN mkdir /app
ADD . /app
WORKDIR /app
RUN go build -o main .
CMD ["/app/main"]
I then start the Docker container:
docker run -it -p 8080:8081 go-app
I would like to enter in numbers in the CLI and then return a response from the HTTP server. How can I do this as the above solution doesn't work (since it doesn't make the GET request within the main() method).

Answer 1

Run the http server in a different goroutine
package main
import (
"fmt"
"log"
"net/http"
)
func main() {
fmt.Println("Enter desired input: ")
// Get user input
var input string
fmt.Scanln(&input)
l, err := net.Listen("tcp", ":8080")
if err != nil {
log.Fatal(err)
}
go func() {
http.HandleFunc("/", doSomething)
log.Fatal(http.Serve(l, nil))
}()
resp, err := http.Get("http://localhost:8080/?input=" + input)
if err != nil {
log.Fatal(err)
}
fmt.Printf("Resp: %v\n", resp)
// Print response out here
}
func doSomething(w http.ResponseWriter, r *http.Request) {
query := r.URL.Query().Get("input")
fmt.Println(query)
// Send response
}