feat: add release workflow, --version flag, and $RSHELL_VERSION

.github/workflows/release.yml

@@ -0,0 +1,58 @@
+name: Release
+
+on:
+  workflow_dispatch:
+
+permissions:
+  contents: write
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    environment: release
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          fetch-depth: 0
+
+      - name: Compute next version
+        id: version
+        run: |
+          # Find the latest semver tag.
+          LATEST=$(git tag --list 'v[0-9]*.[0-9]*.[0-9]*' --sort=-v:refname | head -1)
+          if [ -z "$LATEST" ]; then
+            echo "::error::No existing version tags found."
+            exit 1
+          fi
+
+          # Strip the leading "v" and split into components.
+          CURRENT="${LATEST#v}"
+          IFS='.' read -r MAJOR MINOR PATCH <<< "$CURRENT"
+
+          PATCH=$((PATCH + 1))
+
+          NEXT="${MAJOR}.${MINOR}.${PATCH}"
+          echo "current=$CURRENT" >> "$GITHUB_OUTPUT"
+          echo "next=$NEXT" >> "$GITHUB_OUTPUT"
+          echo "Releasing: v$CURRENT → v$NEXT (patch bump)"
+
+      - name: Check tag does not already exist
+        run: |
+          if git rev-parse "v${{ steps.version.outputs.next }}" >/dev/null 2>&1; then
+            echo "::error::Tag v${{ steps.version.outputs.next }} already exists."
+            exit 1
+          fi
+
+      - name: Tag and push
+        run: |
+          git tag "v${{ steps.version.outputs.next }}"
+          git push origin main "v${{ steps.version.outputs.next }}"
+
+      - name: Create GitHub release
+        run: |
+          gh release create "v${{ steps.version.outputs.next }}" \
+            --title "v${{ steps.version.outputs.next }}" \
+            --generate-notes
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

cmd/rshell/main.go

@@ -17,6 +17,7 @@ import (
 	"time"
 
 	"github.com/DataDog/rshell/internal/interpoption"
+	"github.com/DataDog/rshell/internal/version"
 	"github.com/DataDog/rshell/interp"
 	"github.com/spf13/cobra"
 )
@@ -40,6 +41,7 @@ func run(ctx context.Context, args []string, stdin io.Reader, stdout, stderr io.
 	cmd := &cobra.Command{
 		Use:           "rshell [file ...]",
 		Short:         "A restricted shell interpreter for AI agents",
+		Version:       version.Version,
 		SilenceUsage:  true,
 		SilenceErrors: true,
 		Args:          cobra.ArbitraryArgs,

cmd/rshell/main_test.go

@@ -154,6 +154,18 @@ func TestHelp(t *testing.T) {
 	assert.NotContains(t, stdout, "--command", "-c/--command should be hidden from help")
 }
 
+// TestVersion verifies that --version exits 0 and prints the version.
+// In tests rshell is the main module, so debug.ReadBuildInfo returns "(devel)"
+// and the version falls back to "dev". When imported as a library (e.g. by the
+// Datadog Agent) it reports the real version from go.mod — see
+// TestBuildVersionAsDependency in internal/version/.
+func TestVersion(t *testing.T) {
+	code, stdout, _ := runCLI(t, "--version")
+	t.Logf("stdout: %q", stdout)
+	assert.Equal(t, 0, code)
+	assert.Equal(t, "rshell version dev\n", stdout)
+}
+
 func TestFileArg(t *testing.T) {
 	dir := t.TempDir()
 	script := filepath.Join(dir, "test.sh")

internal/version/testdata/depcheck/go.mod

@@ -0,0 +1,15 @@
+module depcheck
+
+go 1.25.6
+
+require github.com/DataDog/rshell v0.0.10
+
+require (
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/prometheus-community/pro-bing v0.8.0 // indirect
+	github.com/spf13/pflag v1.0.10 // indirect
+	golang.org/x/net v0.52.0 // indirect
+	golang.org/x/sync v0.20.0 // indirect
+	golang.org/x/sys v0.42.0 // indirect
+	mvdan.cc/sh/v3 v3.13.0 // indirect
+)

internal/version/testdata/depcheck/go.sum

@@ -0,0 +1,34 @@
+github.com/DataDog/rshell v0.0.10 h1:1jFuWzxxBNCv4tec1Rn1yZJrj9p3ZK7sRZEaHdxUk0Q=
+github.com/DataDog/rshell v0.0.10/go.mod h1:e6IP68xHScumYqM/9dT9y5H41EmStHDVEyCZKv5mEt4=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-quicktest/qt v1.101.0 h1:O1K29Txy5P2OK0dGo59b7b0LR6wKfIhttaAhHUyn7eI=
+github.com/go-quicktest/qt v1.101.0/go.mod h1:14Bz/f7NwaXPtdYEgzsx46kqSxVwTbzVZsDC26tQJow=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus-community/pro-bing v0.8.0 h1:CEY/g1/AgERRDjxw5P32ikcOgmrSuXs7xon7ovx6mNc=
+github.com/prometheus-community/pro-bing v0.8.0/go.mod h1:Idyxz8raDO6TgkUN6ByiEGvWJNyQd40kN9ZUeho3lN0=
+github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
+github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
+github.com/spf13/pflag v1.0.10 h1:4EBh2KAYBwaONj6b2Ye1GiHfwjqyROoF4RwYO+vPwFk=
+github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+golang.org/x/net v0.52.0 h1:He/TN1l0e4mmR3QqHMT2Xab3Aj3L9qjbhRm78/6jrW0=
+golang.org/x/net v0.52.0/go.mod h1:R1MAz7uMZxVMualyPXb+VaqGSa3LIaUqk0eEt3w36Sw=
+golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
+golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
+golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
+golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+mvdan.cc/sh/v3 v3.13.0 h1:dSfq/MVsY4w0Vsi6Lbs0IcQquMVqLdKLESAOZjuHdLg=
+mvdan.cc/sh/v3 v3.13.0/go.mod h1:KV1GByGPc/Ho0X1E6Uz9euhsIQEj4hwyKnodLlFLoDM=

internal/version/testdata/depcheck/main.go

@@ -0,0 +1,30 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2026-present Datadog, Inc.
+
+// Program depcheck prints the rshell version as seen from an external module
+// that imports rshell as a dependency. Used by TestBuildVersionAsDependency.
+package main
+
+import (
+	"fmt"
+	"runtime/debug"
+
+	_ "github.com/DataDog/rshell/interp" // ensure rshell appears in deps
+)
+
+func main() {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		fmt.Println("NO_BUILD_INFO")
+		return
+	}
+	for _, dep := range info.Deps {
+		if dep.Path == "github.com/DataDog/rshell" {
+			fmt.Println(dep.Version)
+			return
+		}
+	}
+	fmt.Println("NOT_FOUND")
+}

internal/version/version.go

@@ -0,0 +1,41 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2026-present Datadog, Inc.
+
+// Package version exposes the build version of rshell.
+//
+// When rshell is imported as a library (e.g. by the Datadog Agent), Version
+// is read from Go's embedded dependency info via [debug.ReadBuildInfo].
+package version
+
+import "runtime/debug"
+
+const modulePath = "github.com/DataDog/rshell"
+
+// Version is the build version string.
+var Version = buildVersion()
+
+// buildVersion reads the rshell version from Go's embedded build info.
+// When rshell is a dependency (e.g. in the Datadog Agent), the version
+// from go.mod is embedded automatically. For standalone builds it returns "dev".
+// Can be overridden via ldflags:
+//
+//	go build -ldflags "-X github.com/DataDog/rshell/internal/version.Version=custom"
+func buildVersion() string {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "dev"
+	}
+	// When built as a standalone binary, check the main module.
+	if info.Main.Path == modulePath && info.Main.Version != "" && info.Main.Version != "(devel)" {
+		return info.Main.Version
+	}
+	// When imported as a library, find ourselves in the dependency list.
+	for _, dep := range info.Deps {
+		if dep.Path == modulePath {
+			return dep.Version
+		}
+	}
+	return "dev"
+}

internal/version/version_test.go

@@ -0,0 +1,64 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2026-present Datadog, Inc.
+
+package version
+
+import (
+	"os/exec"
+	"strings"
+	"testing"
+)
+
+func TestVersionNotEmpty(t *testing.T) {
+	// In normal test runs (go test), buildVersion returns "dev" because
+	// the module is the main module built as (devel). That's fine — we
+	// just verify it's never empty.
+	if Version == "" {
+		t.Fatal("Version must not be empty")
+	}
+}
+
+func TestBuildVersionFallback(t *testing.T) {
+	// When running tests, the module is the main module so ReadBuildInfo
+	// returns (devel) for Main.Version. buildVersion should return "dev".
+	v := buildVersion()
+	if v == "" {
+		t.Fatal("buildVersion() must not return empty string")
+	}
+	if v != "dev" {
+		t.Logf("buildVersion() = %q (expected 'dev' in test, got something else — ldflags?)", v)
+	}
+}
+
+// TestBuildVersionAsDependency verifies that debug.ReadBuildInfo() reports
+// the correct version when rshell is imported as a dependency by another
+// module. This is the primary use case (the Datadog Agent imports rshell).
+//
+// The test uses testdata/depcheck/ — a standalone Go module that depends on
+// a published version of rshell (v0.0.10). The depcheck program doesn't use
+// rshell's version package — it only blank-imports rshell/interp so that
+// rshell appears in the binary's dependency list, then calls ReadBuildInfo()
+// to verify the version is present. This tests the Go embedding mechanism
+// that our buildVersion() relies on, not rshell's code itself, so the
+// specific version imported doesn't matter.
+func TestBuildVersionAsDependency(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping: requires building an external module")
+	}
+
+	// Build and run the depcheck program directly from testdata.
+	run := exec.Command("go", "run", ".")
+	run.Dir = "testdata/depcheck"
+	out, err := run.Output()
+	if err != nil {
+		t.Fatalf("go run failed: %v", err)
+	}
+
+	got := strings.TrimSpace(string(out))
+	const want = "v0.0.10"
+	if got != want {
+		t.Fatalf("expected version %q from build info deps, got %q", want, got)
+	}
+}

interp/api.go

@@ -28,6 +28,7 @@ import (
 
 	"github.com/DataDog/rshell/allowedpaths"
 	"github.com/DataDog/rshell/builtins"
+	"github.com/DataDog/rshell/internal/version"
 )
 
 // runnerConfig holds the immutable configuration of a [Runner].
@@ -421,6 +422,7 @@ func (r *Runner) Reset() {
 	}
 	r.writeEnv = &overlayEnviron{parent: r.Env}
 	r.setVarString("PWD", r.Dir)
+	r.setVarString("RSHELL_VERSION", version.Version)
 	// IFS is intentionally mutable: scripts may set it to customise field splitting,
 	// which is standard POSIX behaviour. Callers that provide a custom ExecHandler
 	// should be aware that a script can set IFS to a non-whitespace value (e.g.

tests/scenarios/shell/environment/rshell_version_is_set.yaml

@@ -0,0 +1,9 @@
+description: "RSHELL_VERSION is set (like BASH_VERSION in bash)"
+skip_assert_against_bash: true
+input:
+  script: |+
+    echo "$RSHELL_VERSION"
+expect:
+  stdout: |+
+    dev
+  exit_code: 0