Release binaries named fmsg, and fmsg --version

.github/workflows/release.yml

@@ -0,0 +1,59 @@
+name: Release
+
+# Builds the fmsg binary for each platform and attaches the archives to the
+# GitHub release. Runs when a release is published; run it by hand with a tag
+# to (re)build an existing release's binaries.
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: Release tag to build, e.g. v0.3.0
+        required: true
+
+permissions:
+  contents: write
+
+jobs:
+  binaries:
+    runs-on: ubuntu-latest
+    env:
+      TAG: ${{ github.event.release.tag_name || inputs.tag }}
+    steps:
+      - uses: actions/checkout@v7
+        with:
+          ref: ${{ env.TAG }}
+
+      - name: Set up Go
+        uses: actions/setup-go@v7
+        with:
+          go-version: "1.27.x"
+
+      - name: Build
+        run: |
+          set -euo pipefail
+          mkdir -p dist
+          for target in linux/amd64 linux/arm64 darwin/amd64 darwin/arm64 windows/amd64 windows/arm64; do
+            os=${target%/*}
+            arch=${target#*/}
+            bin=fmsg
+            [ "$os" = windows ] && bin=fmsg.exe
+            out="build/${os}_${arch}"
+            mkdir -p "$out"
+            CGO_ENABLED=0 GOOS=$os GOARCH=$arch go build -trimpath \
+              -ldflags "-s -w -X github.com/markmnl/fmsg-cli/cmd.version=$TAG" \
+              -o "$out/$bin" .
+            cp LICENSE README.md "$out/"
+            if [ "$os" = windows ]; then
+              (cd "$out" && zip -q "$GITHUB_WORKSPACE/dist/fmsg_${os}_${arch}.zip" "$bin" LICENSE README.md)
+            else
+              tar -C "$out" -czf "dist/fmsg_${os}_${arch}.tar.gz" "$bin" LICENSE README.md
+            fi
+          done
+          (cd dist && sha256sum * > checksums.txt)
+
+      - name: Upload to the release
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: gh release upload "$TAG" dist/* --clobber

README.md

@@ -5,11 +5,26 @@
 
 Command-line interface to [fmsg-webapi](https://github.com/markmnl/fmsg-webapi) fronting a fmsgd instance.
 
-## Requirements
+## Install
 
-- Go 1.27 or newer
+Download the `fmsg` binary for your platform from the
+[latest release](https://github.com/markmnl/fmsg-cli/releases/latest), e.g. on
+Linux (x86-64):
 
-## Build
+```sh
+curl -fsSL https://github.com/markmnl/fmsg-cli/releases/latest/download/fmsg_linux_amd64.tar.gz | tar -xz fmsg
+sudo mv fmsg /usr/local/bin/
+fmsg --version
+```
+
+Archives are named `fmsg_<os>_<arch>` for `linux`, `darwin` (macOS) and
+`windows` (a `.zip`), on `amd64` and `arm64`; `checksums.txt` has their
+SHA-256 sums. Publishing a GitHub release builds and attaches them
+(`.github/workflows/release.yml`).
+
+## Build from source
+
+Requires Go 1.27 or newer.
 
 ```sh
 go build -o fmsg

cmd/root.go

@@ -6,15 +6,33 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"runtime/debug"
 	"slices"
 	"unicode"
 
 	"github.com/spf13/cobra"
 )
 
+// version is set by release builds with
+// -ldflags "-X github.com/markmnl/fmsg-cli/cmd.version=v1.2.3".
+var version = ""
+
+// buildVersion reports the release version, falling back to the module
+// version recorded by `go install ...@version`, then "dev".
+func buildVersion() string {
+	if version != "" {
+		return version
+	}
+	if info, ok := debug.ReadBuildInfo(); ok && info.Main.Version != "" && info.Main.Version != "(devel)" {
+		return info.Main.Version
+	}
+	return "dev"
+}
+
 var rootCmd = &cobra.Command{
-	Use:   "fmsg",
-	Short: "fmsg — command-line interface to an fmsg messaging server",
+	Use:     "fmsg",
+	Version: buildVersion(),
+	Short:   "fmsg — command-line interface to an fmsg messaging server",
 	Long: `fmsg is a CLI that communicates with an fmsg-webapi server.
 
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