[Fix #1604] Shell refactor

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowApplication.java

@@ -70,6 +70,7 @@
 import java.util.Optional;
 import java.util.ServiceLoader;
 import java.util.ServiceLoader.Provider;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -112,6 +113,7 @@ public class WorkflowApplication implements AutoCloseable {
   private final AllStrategyCorrelationInfoFactory allStrategyCorrelationInfoFactory;
   private final WorkflowLifeCycleCloudEventFactory lifeCycleCloudEventFactory;
   private final ScheduledExecutorService schedulerExecutorService;
+  private final Set<String> allowedCommands;
 
   private WorkflowApplication(Builder builder) {
     this.taskFactory = builder.taskFactory;
@@ -147,6 +149,7 @@ private WorkflowApplication(Builder builder) {
     this.allStrategyCorrelationInfoFactory = builder.allStrategyCorrelationInfoFactory;
     this.lifeCycleCloudEventFactory = builder.lifeCycleCloudEventFactory;
     this.schedulerExecutorService = builder.schedulerExecutorService;
+    this.allowedCommands = Collections.unmodifiableSet(builder.allowedCommands);
   }
 
   public TaskExecutorFactory taskFactory() {
@@ -274,6 +277,7 @@ public SchemaValidator getValidator(SchemaInline inline) {
     private WorkflowLifeCycleCloudEventFactory lifeCycleCloudEventFactory;
     private CronResolverFactory cronResolverFactory;
     private ScheduledExecutorService schedulerExecutorService;
+    private Set<String> allowedCommands = new HashSet<>();
 
     private Builder() {
       ServiceLoader.load(NamedWorkflowAdditionalObject.class)
@@ -396,6 +400,16 @@ public Builder withModelFactory(WorkflowModelFactory modelFactory) {
       return this;
     }
 
+    public Builder withAllowedCommand(String command) {
+      this.allowedCommands.add(command);
+      return this;
+    }
+
+    public Builder withAllowedCommands(Collection<String> commands) {
+      this.allowedCommands.addAll(commands);
+      return this;
+    }
+
     public Builder withContextFactory(WorkflowModelFactory contextFactory) {
       this.contextFactory = contextFactory;
       return this;
@@ -690,4 +704,8 @@ public AllStrategyCorrelationInfoFactory allStrategyCorrelationInfoFactory() {
   public WorkflowLifeCycleCloudEventFactory lifeCycleCloudEventFactory() {
     return lifeCycleCloudEventFactory;
   }
+
+  public Set<String> allowedCommands() {
+    return allowedCommands;
+  }
 }

impl/core/src/main/java/io/serverlessworkflow/impl/executors/RunShellExecutor.java

@@ -23,23 +23,23 @@
 import io.serverlessworkflow.impl.WorkflowModel;
 import io.serverlessworkflow.impl.WorkflowValueResolver;
 import io.serverlessworkflow.impl.scripts.ScriptUtils;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 
 public class RunShellExecutor implements CallableTask {
   private final WorkflowValueResolver<String> shellCommand;
-  private final Map<WorkflowValueResolver<String>, Optional<WorkflowValueResolver<String>>>
-      shellArguments;
+  private final List<WorkflowValueResolver<String>> shellArguments;
   private final Optional<WorkflowValueResolver<Map<String, Object>>> shellEnv;
   private final Optional<ProcessReturnType> returnType;
 
   public RunShellExecutor(
       WorkflowValueResolver<String> shellCommand,
-      Map<WorkflowValueResolver<String>, Optional<WorkflowValueResolver<String>>> shellArguments,
+      List<WorkflowValueResolver<String>> shellArguments,
       Optional<WorkflowValueResolver<Map<String, Object>>> shellEnv,
       Optional<ProcessReturnType> returnType) {
-    super();
     this.shellCommand = shellCommand;
     this.shellArguments = shellArguments;
     this.shellEnv = shellEnv;
@@ -49,16 +49,21 @@ public RunShellExecutor(
   @Override
   public CompletableFuture<WorkflowModel> apply(
       WorkflowContext workflowContext, TaskContext taskContext, WorkflowModel model) {
-    StringBuilder commandBuilder =
-        new StringBuilder(shellCommand.apply(workflowContext, taskContext, model));
-    for (var entry : shellArguments.entrySet()) {
-      commandBuilder.append(" ").append(entry.getKey().apply(workflowContext, taskContext, model));
-      entry
-          .getValue()
-          .ifPresent(
-              v -> commandBuilder.append("=").append(v.apply(workflowContext, taskContext, model)));
+
+    String command = shellCommand.apply(workflowContext, taskContext, model);
+    if (!workflowContext.definition().application().allowedCommands().contains(command)) {
+      return CompletableFuture.failedFuture(
+          new SecurityException(
+              "Command "
+                  + command
+                  + " is not allowed. Please verify the set of allowed commands passed to the application"));
     }
-    ProcessBuilder builder = new ProcessBuilder("sh", "-c", commandBuilder.toString());
+
+    List<String> commandAndArgs = new ArrayList<>();
+    commandAndArgs.add(command);
+    shellArguments.forEach(f -> commandAndArgs.add(f.apply(workflowContext, taskContext, model)));
+
+    ProcessBuilder builder = new ProcessBuilder(commandAndArgs);
     shellEnv.ifPresent(
         map -> ScriptUtils.addEnviromment(builder, map.apply(workflowContext, taskContext, model)));
 

impl/core/src/main/java/io/serverlessworkflow/impl/executors/RunShellExecutorBuilder.java

@@ -20,10 +20,8 @@
 import io.serverlessworkflow.api.types.Shell;
 import io.serverlessworkflow.impl.WorkflowDefinition;
 import io.serverlessworkflow.impl.WorkflowUtils;
-import java.util.LinkedHashMap;
-import java.util.Map;
+import java.util.List;
 import java.util.Optional;
-import java.util.stream.Collectors;
 
 public class RunShellExecutorBuilder implements RunnableTaskBuilder<RunShell> {
 
@@ -37,19 +35,10 @@ public CallableTask build(RunShell taskConfiguration, WorkflowDefinition definit
         WorkflowUtils.buildStringFilter(
             definition.application(), taskConfiguration.getShell().getCommand()),
         shell.getArguments() != null
-            ? shell.getArguments().getAdditionalProperties().entrySet().stream()
-                .collect(
-                    Collectors.toMap(
-                        e -> WorkflowUtils.buildStringFilter(definition.application(), e.getKey()),
-                        e ->
-                            e.getValue() != null
-                                ? Optional.of(
-                                    WorkflowUtils.buildStringFilter(
-                                        definition.application(), e.getValue().toString()))
-                                : Optional.empty(),
-                        (x, y) -> y,
-                        LinkedHashMap::new))
-            : Map.of(),
+            ? shell.getArguments().stream()
+                .map(s -> WorkflowUtils.buildStringFilter(definition.application(), s))
+                .toList()
+            : List.of(),
         shell.getEnvironment() != null
             ? Optional.of(
                 WorkflowUtils.buildMapResolver(