find version string in a more reliable way

.gitignore

@@ -1,5 +1,4 @@
 # build artifacts
-/pkg/util/version.go
 /build
 /.gopath/pkg/
 /.golangvend-cache/

Dockerfile

@@ -1,6 +1,6 @@
 FROM golang:1.8.3-alpine3.6 as builder
 WORKDIR /x/src/github.com/sapcc/swift-http-import/
-RUN apk add --no-cache curl make openssl && \
+RUN apk add --no-cache curl make openssl bash && \
     mkdir -p /pkg/bin/ && \
     curl -L https://github.com/Yelp/dumb-init/releases/download/v1.2.0/dumb-init_1.2.0_amd64 > /pkg/bin/dumb-init && \
     chmod +x /pkg/bin/dumb-init

Makefile

@@ -8,10 +8,8 @@ GO            := GOPATH=$(CURDIR)/.gopath GOBIN=$(CURDIR)/build go
 GO_BUILDFLAGS :=
 GO_LDFLAGS    := -s -w
 
-build/swift-http-import: pkg/util/version.go FORCE
-	$(GO) install $(GO_BUILDFLAGS) -ldflags '$(GO_LDFLAGS)' '$(PKG)'
-pkg/util/version.go: FORCE
-	util/find_version.sh
+build/swift-http-import: FORCE
+	$(GO) install $(GO_BUILDFLAGS) -ldflags '$(GO_LDFLAGS) -X github.com/sapcc/swift-http-import/pkg/util.Version=$(shell util/find_version.sh)' '$(PKG)'
 
 check: all
 	bash tests.sh http

pkg/util/version.go

@@ -0,0 +1,23 @@
+/*******************************************************************************
+*
+* Copyright 2018 SAP SE
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You should have received a copy of the License along with this
+* program. If not, you may obtain a copy of the License at
+*
+*     http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*
+*******************************************************************************/
+
+package util
+
+//Version is the version number of swift-http-import.
+var Version string

util/find_version.sh

@@ -1,25 +1,2 @@
-#!/bin/bash
-#
-# When run in the repository root directory, produces `pkg/util/version.go`.
-#
-
-if [ -d .git ]; then
-    # best option: use git-describe
-    VERSION="$(git describe --tags --dirty)"
-else
-    # second-best option: when running inside an unpacked release tarball, the
-    # root directory's name indicates the version, e.g. "swift-http-import-1.2"
-    root_basename="$(basename "$(readlink -f .)")"
-    if [[ $root_basename =~ swift-http-import-* ]]; then
-        VERSION="${root_basename/swift-http-import-/}"
-    else
-        echo "Cannot determine application version. The root directory basename should look like 'swift-http-import-1.2.3', but actually is '$root_basename'." >&2
-        exit 1
-    fi
-fi
-
-cat > pkg/util/version.go <<-EOF
-//WARNING: this file is autogenerated by util/find_version.sh
-package util
-const Version = "$VERSION"
-EOF
+#!/bin/sh
+awk '$1 == "#" && !/TBD/ { print $2 }' CHANGELOG.md | sed 's/^v//' | head -n1