embed version into docker image

Dockerfile

@@ -1,8 +1,10 @@
 FROM golang AS build
 
+ARG GIT_DESC=undefined
+
 WORKDIR /go/src/github.com/Snawoot/hola-proxy
 COPY . .
-RUN CGO_ENABLED=0 go build -a -tags netgo -ldflags '-s -w -extldflags "-static"'
+RUN CGO_ENABLED=0 go build -a -tags netgo -ldflags '-s -w -extldflags "-static" -X main.version=$GIT_DESC'
 ADD https://curl.haxx.se/ca/cacert.pem /certs.crt
 RUN chmod 0644 /certs.crt
 

hooks/build

@@ -0,0 +1,2 @@
+#!/bin/bash
+docker build --build-arg GIT_DESC="$(git describe)" -f "$DOCKERFILE_PATH" -t "$IMAGE_NAME" .