ensure CI builds the latest commit

The Go proxy is highly unlikely to be up to date already when a commit is pushed.

2 files changed, 9 insertions, 7 deletions

diff --git a/Dockerfile b/Dockerfile
index 44edb5f..62ac15e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,12 +1,14 @@
 FROM --platform=${BUILDPLATFORM} golang:1.21.4
 
-ARG version=latest
+ARG VERSION
 ARG BUILDPLATFORM
 ARG BUILDARCH
 ARG TARGETARCH
 
+COPY . /go/src/github.com/HimbeerserverDE/mt-multiserver-proxy
+
 RUN mkdir /usr/local/mt-multiserver-proxy
-RUN GOARCH=${TARGETARCH} go install github.com/HimbeerserverDE/mt-multiserver-proxy/cmd/...@${version}
+RUN GOARCH=${TARGETARCH} go install github.com/HimbeerserverDE/mt-multiserver-proxy/cmd/...@${VERSION:-`(cd /go/src/github.com/HimbeerserverDE/mt-multiserver-proxy && TZ=UTC git --no-pager show --quiet --abbrev=12 --date='format-local:%Y%m%d%H%M%S' --format='v0.0.0-%cd-%h')`}
 RUN if [ "${TARGETARCH}" = "${BUILDARCH}" ]; then mv /go/bin/mt-* /usr/local/mt-multiserver-proxy/; else mv /go/bin/linux_${TARGETARCH}/mt-* /usr/local/mt-multiserver-proxy/; fi
 
 VOLUME ["/usr/local/mt-multiserver-proxy"]
diff --git a/doc/docker.md b/doc/docker.md
index 6af77c5..9ff9c38 100644
--- a/doc/docker.md
+++ b/doc/docker.md
@@ -1,8 +1,7 @@
 # Docker
 
 This repository contains a `Dockerfile` at its root.
-It can be used to build the most recent release version
-or a development version into an image.
+It can be used to build a release or development version into an image.
 
 ## Build
 
@@ -15,14 +14,14 @@ The images are intended to be built by the default buildx builder.
 
 ### Regular
 
-To build an image of the latest commit, run the following command
+To build an image of the current commit, run the following command
 from the repository root:
 
 ```
 docker buildx build -t mt-multiserver-proxy --load .
 ```
 
-This is the version most people will want.
+This works well with CI because it doesn't rely on the Go proxy being up-to-date.
 
 It is also possible to build a specific version into an image:
 
@@ -30,7 +29,8 @@ It is also possible to build a specific version into an image:
 docker buildx build -t mt-multiserver-proxy --load --build-arg version=VERSION .
 ```
 
-where `VERSION` is a Go pseudo-version.
+where `VERSION` is a Go pseudo-version or `latest` for the latest version
+known by the Go proxy.
 
 ### Development