support runner.arch (#1290)

* support runner.arch

Signed-off-by: Fabian Kammel <fk@edgeless.systems>

* add arch to runner definition

Signed-off-by: Fabian Kammel <fk@edgeless.systems>

* get architecture from docker

Signed-off-by: Fabian Kammel <fk@edgeless.systems>

* Update pkg/container/docker_run.go

Co-authored-by: ChristopherHX <christopher.homberger@web.de>

* lint: goimport file

Signed-off-by: Fabian Kammel <fk@edgeless.systems>
Co-authored-by: Casey Lee <caseypl@amazon.com>
Co-authored-by: ChristopherHX <christopher.homberger@web.de>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

pkg/container/docker_run.go

@@ -276,6 +276,26 @@ func GetHostInfo(ctx context.Context) (info types.Info, err error) {
 	return info, nil
 }
 
+// Arch fetches values from docker info and translates architecture to
+// GitHub actions compatible runner.arch values
+// https://github.com/github/docs/blob/main/data/reusables/actions/runner-arch-description.md
+func RunnerArch(ctx context.Context) string {
+	info, err := GetHostInfo(ctx)
+	if err != nil {
+		return ""
+	}
+
+	archMapper := map[string]string{
+		"x86_64":  "X64",
+		"386":     "x86",
+		"aarch64": "arm64",
+	}
+	if arch, ok := archMapper[info.Architecture]; ok {
+		return arch
+	}
+	return info.Architecture
+}
+
 func (cr *containerReference) connect() common.Executor {
 	return func(ctx context.Context) error {
 		if cr.cli != nil {

pkg/runner/action.go

@@ -346,6 +346,7 @@ func newStepContainer(ctx context.Context, step step, image string, cmd []string
 
 	envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_TOOL_CACHE", "/opt/hostedtoolcache"))
 	envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_OS", "Linux"))
+	envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_ARCH", container.RunnerArch(ctx)))
 	envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_TEMP", "/tmp"))
 
 	binds, mounts := rc.GetBindsAndMounts()

pkg/runner/expression.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/nektos/act/pkg/common"
+	"github.com/nektos/act/pkg/container"
 	"github.com/nektos/act/pkg/exprparser"
 	"gopkg.in/yaml.v3"
 )
@@ -47,6 +48,7 @@ func (rc *RunContext) NewExpressionEvaluator(ctx context.Context) ExpressionEval
 		Steps: rc.getStepsContext(),
 		Runner: map[string]interface{}{
 			"os":         "Linux",
+			"arch":       container.RunnerArch(ctx),
 			"temp":       "/tmp",
 			"tool_cache": "/opt/hostedtoolcache",
 		},
@@ -92,6 +94,7 @@ func (rc *RunContext) NewStepExpressionEvaluator(ctx context.Context, step step)
 		Steps:  rc.getStepsContext(),
 		Runner: map[string]interface{}{
 			"os":         "Linux",
+			"arch":       container.RunnerArch(ctx),
 			"temp":       "/tmp",
 			"tool_cache": "/opt/hostedtoolcache",
 		},

pkg/runner/run_context.go

@@ -149,6 +149,7 @@ func (rc *RunContext) startJobContainer() common.Executor {
 
 		envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_TOOL_CACHE", "/opt/hostedtoolcache"))
 		envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_OS", "Linux"))
+		envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_ARCH", container.RunnerArch(ctx)))
 		envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_TEMP", "/tmp"))
 
 		binds, mounts := rc.GetBindsAndMounts()

pkg/runner/step_docker.go

@@ -105,6 +105,7 @@ func (sd *stepDocker) newStepContainer(ctx context.Context, image string, cmd []
 
 	envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_TOOL_CACHE", "/opt/hostedtoolcache"))
 	envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_OS", "Linux"))
+	envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_ARCH", container.RunnerArch(ctx)))
 	envList = append(envList, fmt.Sprintf("%s=%s", "RUNNER_TEMP", "/tmp"))
 
 	binds, mounts := rc.GetBindsAndMounts()