Changed build.sh from bash to pure sh (I see no bash-specifics in there). Added Dockerfile based on golang:alpine

Signed-off-by: Marcel Parciak <marcel.parciak@gmail.com>

Dockerfile

@@ -0,0 +1,13 @@
+FROM golang:alpine
+
+LABEL maintainer="marcel.parciak@mgmail.com"
+ENV TOKEN ""
+
+WORKDIR /etc/postwoman-proxy
+
+COPY . /etc/postwoman-proxy
+RUN ./build.sh linux server
+
+EXPOSE 9159/tcp
+
+CMD ["sh", "-c", "/etc/postwoman-proxy/out/linux-server/postwoman-proxy-server --host 0.0.0.0:9159 --token $TOKEN"]

build.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 if [ $# -lt 1 ]; then
   echo "Usage: $0 <darwin|linux|windows> [<server|desktop>]"