Forward host environment variables to the emulator container

Author: gtsiolis

internal/container/start.go

@@ -96,6 +96,13 @@ func Start(ctx context.Context, rt runtime.Runtime, sink output.Sink, opts Start
 
 	tel := opts.Telemetry
 
+	var hostEnv []string
+	for _, e := range os.Environ() {
+		if strings.HasPrefix(e, "CI=") || (strings.HasPrefix(e, "LOCALSTACK_") && !strings.HasPrefix(e, "LOCALSTACK_AUTH_TOKEN=")) {
+			hostEnv = append(hostEnv, e)
+		}
+	}
+
 	containers := make([]runtime.ContainerConfig, len(opts.Containers))
 	for i, c := range opts.Containers {
 		image, err := c.Image()
@@ -128,6 +135,8 @@ func Start(ctx context.Context, rt runtime.Runtime, sink output.Sink, opts Start
 			"MAIN_CONTAINER_NAME="+containerName,
 		)
 
+		env = append(env, hostEnv...)
+
 		var binds []runtime.BindMount
 		if socketPath := rt.SocketPath(); socketPath != "" {
 			binds = append(binds, runtime.BindMount{HostPath: socketPath, ContainerPath: "/var/run/docker.sock"})

internal/container/start_test.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"errors"
 	"io"
+	"strings"
 	"testing"
 
 	"github.com/localstack/lstk/internal/log"
@@ -64,3 +65,26 @@ func TestServicePortRange_ReturnsExpectedPorts(t *testing.T) {
 	assert.Equal(t, "4559", ports[50].ContainerPort)
 	assert.Equal(t, "4559", ports[50].HostPort)
 }
+
+func TestFilterHostEnv(t *testing.T) {
+	tests := []struct {
+		name     string
+		env      string
+		expected bool
+	}{
+		{"CI is included", "CI=true", true},
+		{"LOCALSTACK_DISABLE_EVENTS is included", "LOCALSTACK_DISABLE_EVENTS=1", true},
+		{"LOCALSTACK_HOST is included", "LOCALSTACK_HOST=0.0.0.0", true},
+		{"LOCALSTACK_AUTH_TOKEN is excluded", "LOCALSTACK_AUTH_TOKEN=secret", false},
+		{"PATH is excluded", "PATH=/usr/bin", false},
+		{"HOME is excluded", "HOME=/root", false},
+		{"LOCALSTACK_BUILD_VERSION is included", "LOCALSTACK_BUILD_VERSION=3.0.0", true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := strings.HasPrefix(tt.env, "CI=") || (strings.HasPrefix(tt.env, "LOCALSTACK_") && !strings.HasPrefix(tt.env, "LOCALSTACK_AUTH_TOKEN="))
+			assert.Equal(t, tt.expected, got)
+		})
+	}
+}

test/integration/start_test.go

@@ -226,14 +226,34 @@ func TestStartCommandSetsUpContainerCorrectly(t *testing.T) {
 	})
 }
 
-// containerEnvToMap converts a Docker container's []string env to a map.
-func containerEnvToMap(envList []string) map[string]string {
-	m := make(map[string]string, len(envList))
-	for _, e := range envList {
-		k, v, _ := strings.Cut(e, "=")
-		m[k] = v
-	}
-	return m
+func TestStartCommandPassesCIAndLocalStackEnvVars(t *testing.T) {
+	requireDocker(t)
+	_ = env.Require(t, env.AuthToken)
+
+	cleanup()
+	t.Cleanup(cleanup)
+
+	t.Setenv("CI", "true")
+	t.Setenv("LOCALSTACK_DISABLE_EVENTS", "1")
+	t.Setenv("LOCALSTACK_AUTH_TOKEN", "host-token")
+
+	mockServer := createMockLicenseServer(true)
+	defer mockServer.Close()
+
+	ctx := testContext(t)
+	_, stderr, err := runLstk(t, ctx, "", env.With(env.APIEndpoint, mockServer.URL), "start")
+	require.NoError(t, err, "lstk start failed: %s", stderr)
+	requireExitCode(t, 0, err)
+
+	inspect, err := dockerClient.ContainerInspect(ctx, containerName)
+	require.NoError(t, err, "failed to inspect container")
+	require.True(t, inspect.State.Running)
+
+	envVars := containerEnvToMap(inspect.Config.Env)
+	assert.Equal(t, "true", envVars["CI"])
+	assert.Equal(t, "1", envVars["LOCALSTACK_DISABLE_EVENTS"])
+	assert.NotEmpty(t, envVars["LOCALSTACK_AUTH_TOKEN"])
+	assert.NotEqual(t, "host-token", envVars["LOCALSTACK_AUTH_TOKEN"], "host LOCALSTACK_AUTH_TOKEN should not be passed through")
 }
 
 // hasBindTarget checks if any bind mount targets the given container path.
@@ -247,6 +267,16 @@ func hasBindTarget(binds []string, containerPath string) bool {
 	return false
 }
 
+// containerEnvToMap converts a Docker container's []string env to a map.
+func containerEnvToMap(envList []string) map[string]string {
+	m := make(map[string]string, len(envList))
+	for _, e := range envList {
+		k, v, _ := strings.Cut(e, "=")
+		m[k] = v
+	}
+	return m
+}
+
 func cleanup() {
 	ctx := context.Background()
 	_ = dockerClient.ContainerStop(ctx, containerName, container.StopOptions{})