交叉编译net / http进行分发

Question

I have build the following code in a docker container with the following architecture:
cat /proc/version Linux version 3.16.7-tinycore64 (root@064f0e1ce709) (gcc version 4.7.2 (Debian 4.7.2-5) ) #1 SMP Tue Dec 16 23:03:39 UTC 2014

package main

import "fmt"

func main() {
    fmt.Println("Hello")
}

The binary distributed, runs with no problem on a busybox container, with the same architecture without installing golang.

The problem

When I do the same for the following code:

package main

import (
    "fmt"
    "net/http"
)

const (
    port = ":80"
)

var calls = 0

func HelloWorld(w http.ResponseWriter, r *http.Request) {
    calls++
    fmt.Fprintf(w, "Hello, world! You have called me %d times.
", calls)
}

func init() {
    fmt.Printf("Started server at http://localhost%v.
", port)
    http.HandleFunc("/", HelloWorld)
    http.ListenAndServe(port, nil)
}

func main() {}

Then I get:
ash: ./hello_world: not found

I might be missing some dependencies - like "net/http"?
But I thought the go build would build all into the binaries.
This is for both go build & go install.

Any idea?

Answer 1

The answer is most probably the one described in this article.

Some critical parts of the standard library use CGO [...] if you cross-compile Go to Darwin or Linux your programs won’t use the system DNS resolver. They also can’t use the native host certificate store. They also can’t look up the user’s home directory, either.

And CGO links against some standard system interfaces by default, dynamically.

The article suggests using gonative to fix the problem. If that's not your cup of tea, some people suggest using:

go build -ldflags "-linkmode external -extldflags -static" 

Also read: https://groups.google.com/d/topic/golang-nuts/H-NTwhQVp-8/discussion