ECS / EC2 Metadata entrypoint example

Dockerfile

FROM golang:1.4

COPY entrypoint.sh /entrypoint.sh
COPY main.go main.go
RUN go build -o main main.go
RUN chmod +x /entrypoint.sh

EXPOSE 8080
ENTRYPOINT ["/entrypoint.sh"]
CMD ["./main"]

entrypoint.sh

#!/bin/sh
export HOST=$(curl --retry 5 --connect-timeout 3 -s 169.254.169.254/latest/meta-data/local-hostname)
export LOCAL_IP=$(curl --retry 5 --connect-timeout 3 -s 169.254.169.254/latest/meta-data/local-ipv4)
exec "$@"

main.go

package main

import (
	"encoding/json"
	"log"
	"net/http"
	"os"
)

func main() {
	log.Fatal(http.ListenAndServe(":8080", http.HandlerFunc(func(resp http.ResponseWriter, req *http.Request) {
		resp.Header().Set("Content-Type", "application/json")
		body, err := json.Marshal(map[string]string{"hostname": os.Getenv("HOST"), "localIp": os.Getenv("LOCAL_IP")})
		if err != nil {
			panic(err)
		}
		resp.Write(body)
	})))
}

task-definition.json

{
	"family": "test-hostenv-entrypoint",
	"containerDefinitions": [{
		"name": "test",
		"image": "euank/play:2015-08-10",
		"memory": 50,
		"portMappings": [{
			"containerPort": 8080,
			"hostPort": 8080
		}]
	}]
}

Thank for this, I will try later today. The issue I have had in my attempts is the session the export of the variables is placed. I am using a Spring/Java jar file. Needing to get the env variables into the properties files.