feat: embed version info into binary (#298)

Author: johnstcn

.github/workflows/ci.yaml

@@ -99,24 +99,20 @@ jobs:
       - name: Build
         if: github.event_name == 'pull_request'
         run: |
-          VERSION=$(./scripts/version.sh)-dev-$(git rev-parse --short HEAD)
           BASE=ghcr.io/coder/envbuilder-preview
 
           ./scripts/build.sh \
             --arch=amd64 \
-            --base=$BASE \
-            --tag=$VERSION
+            --base=$BASE
 
       - name: Build and Push
         if: github.ref == 'refs/heads/main'
         run: |
-          VERSION=$(./scripts/version.sh)-dev-$(git rev-parse --short HEAD)
           BASE=ghcr.io/coder/envbuilder-preview
 
           ./scripts/build.sh \
             --arch=amd64 \
             --arch=arm64 \
             --arch=arm \
             --base=$BASE \
-            --tag=$VERSION \
             --push

buildinfo/version.go

@@ -0,0 +1,71 @@
+package buildinfo
+
+import (
+	"fmt"
+	"runtime/debug"
+	"sync"
+
+	"golang.org/x/mod/semver"
+)
+
+const (
+	noVersion       = "v0.0.0"
+	develPreRelease = "devel"
+)
+
+var (
+	buildInfo      *debug.BuildInfo
+	buildInfoValid bool
+	readBuildInfo  sync.Once
+
+	version     string
+	readVersion sync.Once
+
+	// Injected with ldflags at build time
+	tag string
+)
+
+func revision() (string, bool) {
+	return find("vcs.revision")
+}
+
+func find(key string) (string, bool) {
+	readBuildInfo.Do(func() {
+		buildInfo, buildInfoValid = debug.ReadBuildInfo()
+	})
+	if !buildInfoValid {
+		panic("could not read build info")
+	}
+	for _, setting := range buildInfo.Settings {
+		if setting.Key != key {
+			continue
+		}
+		return setting.Value, true
+	}
+	return "", false
+}
+
+// Version returns the semantic version of the build.
+// Use golang.org/x/mod/semver to compare versions.
+func Version() string {
+	readVersion.Do(func() {
+		revision, valid := revision()
+		if valid {
+			revision = "+" + revision[:7]
+		}
+		if tag == "" {
+			// This occurs when the tag hasn't been injected,
+			// like when using "go run".
+			// <version>-<pre-release>+<revision>
+			version = fmt.Sprintf("%s-%s%s", noVersion, develPreRelease, revision)
+			return
+		}
+		version = "v" + tag
+		// The tag must be prefixed with "v" otherwise the
+		// semver library will return an empty string.
+		if semver.Build(version) == "" {
+			version += revision
+		}
+	})
+	return version
+}

envbuilder.go

@@ -24,6 +24,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/coder/envbuilder/buildinfo"
 	"github.com/coder/envbuilder/constants"
 	"github.com/coder/envbuilder/git"
 	"github.com/coder/envbuilder/options"
@@ -89,7 +90,7 @@ func Run(ctx context.Context, opts options.Options) error {
 		}
 	}
 
-	opts.Logger(log.LevelInfo, "%s - Build development environments from repositories in a container", newColor(color.Bold).Sprintf("envbuilder"))
+	opts.Logger(log.LevelInfo, "%s %s - Build development environments from repositories in a container", newColor(color.Bold).Sprintf("envbuilder"), buildinfo.Version())
 
 	cleanupDockerConfigJSON, err := initDockerConfigJSON(opts.DockerConfigBase64)
 	if err != nil {
@@ -863,7 +864,7 @@ func RunCacheProbe(ctx context.Context, opts options.Options) (v1.Image, error)
 		}
 	}
 
-	opts.Logger(log.LevelInfo, "%s - Build development environments from repositories in a container", newColor(color.Bold).Sprintf("envbuilder"))
+	opts.Logger(log.LevelInfo, "%s %s - Build development environments from repositories in a container", newColor(color.Bold).Sprintf("envbuilder"), buildinfo.Version())
 
 	cleanupDockerConfigJSON, err := initDockerConfigJSON(opts.DockerConfigBase64)
 	if err != nil {

scripts/build.sh

@@ -6,7 +6,7 @@ set -euo pipefail
 archs=()
 push=false
 base="envbuilder"
-tag="latest"
+tag=""
 
 for arg in "$@"; do
   if [[ $arg == --arch=* ]]; then
@@ -30,6 +30,10 @@ if [ ${#archs[@]} -eq 0 ]; then
   archs=( "$current" ) 
 fi
 
+if [[ -z "${tag}"  ]]; then
+	tag=$(./version.sh)
+fi
+
 # We have to use docker buildx to tag multiple images with
 # platforms tragically, so we have to create a builder.
 BUILDER_NAME="envbuilder"
@@ -46,9 +50,11 @@ fi
 # Ensure the builder is bootstrapped and ready to use
 docker buildx inspect --bootstrap &> /dev/null
 
+ldflags=(-X "'github.com/coder/envbuilder/buildinfo.tag=$tag'")
+
 for arch in "${archs[@]}"; do
   echo "Building for $arch..."
-  GOARCH=$arch CGO_ENABLED=0 go build -o "./envbuilder-${arch}" ../cmd/envbuilder &
+  GOARCH=$arch CGO_ENABLED=0 go build -ldflags="${ldflags[*]}" -o "./envbuilder-${arch}" ../cmd/envbuilder &
 done
 wait
 
@@ -62,10 +68,12 @@ else
   args+=( --load )
 fi
 
+# coerce semver build tags into something docker won't complain about
+tag="${tag//\+/-}"
 docker buildx build --builder $BUILDER_NAME "${args[@]}" -t "${base}:${tag}" -t "${base}:latest" -f Dockerfile .
 
 # Check if archs contains the current. If so, then output a message!
 if [[ -z "${CI:-}" ]] && [[ " ${archs[*]} " =~ ${current} ]]; then
   docker tag "${base}:${tag}" envbuilder:latest
-  echo "Tagged $current as envbuilder:latest!"
+  echo "Tagged $current as ${base}:${tag} ${base}:latest!"
 fi

scripts/lib.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+# This script is meant to be sourced by other scripts. To source this script:
+#     # shellcheck source=scripts/lib.sh
+#     source "$(dirname "${BASH_SOURCE[0]}")/lib.sh"
+
+set -euo pipefail
+
+# Avoid sourcing this script multiple times to guard against when lib.sh
+# is used by another sourced script, it can lead to confusing results.
+if [[ ${SCRIPTS_LIB_IS_SOURCED:-0} == 1 ]]; then
+	return
+fi
+# Do not export to avoid this value being inherited by non-sourced
+# scripts.
+SCRIPTS_LIB_IS_SOURCED=1
+
+# We have to define realpath before these otherwise it fails on Mac's bash.
+SCRIPT="${BASH_SOURCE[1]:-${BASH_SOURCE[0]}}"
+SCRIPT_DIR="$(realpath "$(dirname "$SCRIPT")")"
+
+function project_root {
+	# Nix sets $src in derivations!
+	[[ -n "${src:-}" ]] && echo "$src" && return
+
+	# Try to use `git rev-parse --show-toplevel` to find the project root.
+	# If this directory is not a git repository, this command will fail.
+	git rev-parse --show-toplevel 2>/dev/null && return
+}
+
+PROJECT_ROOT="$(cd "$SCRIPT_DIR" && realpath "$(project_root)")"
+
+# cdroot changes directory to the root of the repository.
+cdroot() {
+	cd "$PROJECT_ROOT" || error "Could not change directory to '$PROJECT_ROOT'"
+}
+
+# log prints a message to stderr
+log() {
+	echo "$*" 1>&2
+}

scripts/version.sh

@@ -1,10 +1,78 @@
 #!/usr/bin/env bash
 
+# This script generates the version string used by Envbuilder, including for dev
+# versions. Note: the version returned by this script will NOT include the "v"
+# prefix that is included in the Git tag.
+#
+# If $ENVBUILDER_RELEASE is set to "true", the returned version will equal the
+# current git tag. If the current commit is not tagged, this will fail.
+#
+# If $ENVBUILDER_RELEASE is not set, the returned version will always be a dev
+# version.
+
 set -euo pipefail
-cd "$(dirname "${BASH_SOURCE[0]}")"
+# shellcheck source=scripts/lib.sh
+source "$(dirname "${BASH_SOURCE[0]}")/lib.sh"
+cdroot
+
+if [[ -n "${ENVBUILDER_FORCE_VERSION:-}" ]]; then
+	echo "${ENVBUILDER_FORCE_VERSION}"
+	exit 0
+fi
+
+# To make contributing easier, if there are no tags, we'll use a default
+# version.
+tag_list=$(git tag)
+if [[ -z ${tag_list} ]]; then
+	log
+	log "INFO(version.sh): It appears you've checked out a fork or shallow clone of Envbuilder."
+	log "INFO(version.sh): By default GitHub does not include tags when forking."
+	log "INFO(version.sh): We will use the default version 0.0.1 for this build."
+	log "INFO(version.sh): To pull tags from upstream, use the following commands:"
+	log "INFO(version.sh):   - git remote add upstream https://github.com/coder/envbuilder.git"
+	log "INFO(version.sh):   - git fetch upstream"
+	log
+	last_tag="v0.0.1"
+else
+	current_commit=$(git rev-parse HEAD)
+	# Try to find the last tag that contains the current commit
+	last_tag=$(git tag --contains "$current_commit" --sort=version:refname | head -n 1)
+	# If there is no tag that contains the current commit,
+	# get the latest tag sorted by semver.
+	if [[ -z "${last_tag}" ]]; then
+		last_tag=$(git tag --sort=version:refname | tail -n 1)
+	fi
+fi
+
+version="${last_tag}"
+
+# If the HEAD has extra commits since the last tag then we are in a dev version.
+#
+# Dev versions are denoted by the "-dev+" suffix with a trailing commit short
+# SHA.
+if [[ "${ENVBUILDER_RELEASE:-}" == *t* ]]; then
+	# $last_tag will equal `git describe --always` if we currently have the tag
+	# checked out.
+	if [[ "${last_tag}" != "$(git describe --always)" ]]; then
+		# make won't exit on $(shell cmd) failures, so we have to kill it :(
+		if [[ "$(ps -o comm= "${PPID}" || true)" == *make* ]]; then
+			log "ERROR: version.sh: the current commit is not tagged with an annotated tag"
+			kill "${PPID}" || true
+			exit 1
+		fi
+
+		error "version.sh: the current commit is not tagged with an annotated tag"
+	fi
+else
+	rev=$(git rev-parse --short HEAD)
+	version="0.0.0+dev-${rev}"
+	# If the git repo has uncommitted changes, mark the version string as 'dirty'.
+	dirty_files=$(git ls-files --other --modified --exclude-standard)
+	if [[ -n "${dirty_files}" ]]; then
+		version+="-dirty"
+	fi
+fi
 
-last_tag="$(git describe --tags --abbrev=0)"
-version="$last_tag"
 
 # Remove the "v" prefix.
 echo "${version#v}"