Add a version command to print the version of toxstatus and sqlite

.github/workflows/build.yaml

@@ -21,3 +21,10 @@ jobs:
       - name: Build
         run: |
           nix build --print-build-logs
+      - name: Check version number
+        if: startsWith(github.ref_name, 'v')
+        run: |
+          if ! ./result/bin/toxstatus version | grep -q '${{ github.ref_name }}'; then
+            echo "Version information doesn't match"
+            exit 1
+          fi

cmd/toxstatus/cmd/version.go

@@ -0,0 +1,45 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/Tox/ToxStatus/internal/version"
+	sqlite3 "github.com/mattn/go-sqlite3"
+	"github.com/spf13/cobra"
+)
+
+var (
+	versionCmd = &cobra.Command{
+		Use:   "version",
+		Short: "Version information",
+		Run:   startVersion,
+	}
+)
+
+func init() {
+	Root.AddCommand(versionCmd)
+}
+
+func startVersion(cmd *cobra.Command, args []string) {
+	vs, err := version.String()
+	if err != nil {
+		exitWithError(err.Error())
+		return
+	}
+
+	sqliteVersion, _, _ := sqlite3.Version()
+
+	fmt.Print(vs)
+	if ts := version.HumanRevisionTime(); ts != "" {
+		fmt.Printf(" (%s)", ts)
+	}
+	fmt.Println()
+	fmt.Printf("sqlite: %s \n", sqliteVersion)
+	fmt.Println("https://github.com/Tox/ToxStatus (GPLv3)")
+}
+
+func exitWithError(s string) {
+	fmt.Fprintf(os.Stderr, "error: %s\n", s)
+	os.Exit(1)
+}

flake.nix

@@ -6,18 +6,28 @@
   outputs = { self, nixpkgs, flake-utils }:
     flake-utils.lib.eachDefaultSystem (system: let
       pkgs = nixpkgs.legacyPackages.${system};
+      toxStatusVersion = "2.0.0-alpha1";
     in {
       packages = flake-utils.lib.flattenTree rec {
         default = toxstatus;
         toxstatus = with pkgs; buildGoModule rec {
-          name = "toxstatus";
+          pname = "toxstatus";
+          version = toxStatusVersion;
           src = ./.;
 
           subPackages = [ "cmd/toxstatus" ];
           vendorHash = "sha256-cE8L7vuf3msMplL6BfQ4gt1rELMIFswDu9mfSXJ9VAs=";
 
           tags = ["sqlite_foreign_keys"];
 
+          ldflags = let
+            pkgPath = "github.com/Tox/ToxStatus/internal/version";
+          in [
+            "-X ${pkgPath}.Number=${version}"
+            "-X ${pkgPath}.Revision=${self.shortRev or "dirty"}"
+            "-X ${pkgPath}.RevisionTime=${toString self.lastModified}"
+          ];
+
           doCheck = false;
         };
       };

internal/version/version.go

@@ -0,0 +1,30 @@
+package version
+
+import (
+	"fmt"
+	"strconv"
+	"time"
+)
+
+var (
+	Number       string
+	Revision     string
+	RevisionTime string
+)
+
+func String() (string, error) {
+	if Number == "" {
+		return "toxstatus: development build", nil
+	}
+
+	return fmt.Sprintf("toxstatus: v%s-%s", Number, Revision), nil
+}
+
+func HumanRevisionTime() string {
+	secs, err := strconv.ParseInt(RevisionTime, 10, 64)
+	if err != nil {
+		return ""
+	}
+
+	return time.Unix(secs, 0).UTC().String()
+}