Enable building container images with Drone

.drone.yml

@@ -0,0 +1,18 @@
+---
+kind: pipeline
+name: default
+steps:
+- name: docker
+  image: plugins/docker
+  settings:
+    registry: atdr-writer.meo.ws
+    username:
+      from_secret: atdr_user
+    password:
+      from_secret: atdr_pass
+    repo: atdr-writer.meo.ws/archiveteam/transfer.sh
+    dockerfile: Containerfile
+    purge: true
+    auto_tag: false
+    tags:
+    - latest

Dockerfile → Containerfile

@@ -1,6 +1,6 @@
 # Default to Go 1.13
 ARG GO_VERSION=1.13
-FROM golang:${GO_VERSION}-alpine as build
+FROM docker.io/library/golang:${GO_VERSION}-alpine as build
 
 # Necessary to run 'go get' and to compile the linked binary
 RUN apk add git musl-dev
@@ -12,7 +12,7 @@ WORKDIR /go/src/github.com/dutchcoders/transfer.sh
 ENV GO111MODULE=on
 
 # build & install server
-RUN go get -u ./... && CGO_ENABLED=0 go build -ldflags -a -tags netgo -ldflags '-w -extldflags "-static"' -o /go/bin/transfersh github.com/dutchcoders/transfer.sh
+RUN go get ./... && CGO_ENABLED=0 go build -ldflags -a -tags netgo -ldflags '-w -extldflags "-static"' -o /go/bin/transfersh github.com/dutchcoders/transfer.sh
 
 FROM scratch AS final
 LABEL maintainer="Andrea Spacca <andrea.spacca@gmail.com>"