Support Conditional Steps in Composite Actions (#1438)

* conditional support for composite actions

* Fix Conditional function evaluation

* Push launch.json temporarily

* Revert "Push launch.json temporarily"

* rename context

* Cleanup comments

* fix success/failure functions to run based on pre/main steps

* idea of step_status

* change to use steps context, WIP

* add inputs to possible if condition expressions

* use action_status

* pr cleanup

* Added right stages

* Test on stage in conditional functions

* Fix naming and formatting

* Fix tests

* Add success and failure L0s

* Remove comment

* Remove whitespace

* Undo formatting

* Add L0 for step-if parsing

* Add ADR

Co-authored-by: Thomas Boop <thboop@github.com>

docs/adrs/1438-conditional-composite.md

@@ -0,0 +1,71 @@
+# ADR 1438: Support Conditionals In Composite Actions
+
+**Date**: 2021-10-13
+
+**Status**: Accepted
+
+## Context
+
+We recently shipped composite actions, which allows you to reuse individual steps inside an action. 
+However, one of the [most requested features](https://github.com/actions/runner/issues/834) has been a way to support the `if` keyword.
+
+### Goals
+- We want to keep consistent with current behavior
+- We want to support conditionals via the `if` keyword
+- Our built in functions like `success` should be implementable without calling them, for example you can do `job.status == success` rather then `success()` currently.
+
+### How does composite currently work?
+
+Currently, we have limited conditional support in composite actions for `pre` and `post` steps. 
+These are based on the `job status`, and support keywords like `always()`, `failed()`, `success()` and `cancelled()`. 
+However, generic or main steps do **not** support conditionals.
+
+By default, in a regular workflow, a step runs on the `success()` condition. Which looks at the **job** **status**, sees if it is successful and runs.
+
+By default, in a composite action, main steps run until a single step fails in that composite action, then the composite action is halted early. It does **not** care about the job status.
+Pre, and post steps in composite actions use the job status to determine if they should run.
+
+### How do we go forward?
+
+Well, if we think about what composite actions are currently doing when invoking main steps, they are checking if the current composite action is successful. 
+Lets formalize that concept into a "real" idea.
+
+- We will add an `action_status` field to the github context to mimic the [job's context status](https://docs.github.com/en/actions/learn-github-actions/contexts#job-context).
+  - We have an existing concept that does this `action_path` which is only set for composite actions on the github context.
+- In a composite action during a main step, the `success()` function will check if `action_status == success`, rather then `job_status == success`. Failure will work the same way. 
+  - Pre and post steps in composite actions will not change, they will continue to check the job status.
+
+
+### Nested Scenario
+For nested composite actions, we will follow the existing behavior, you only care about your current composite action, not any parents. 
+For example, lets imagine a scenario with a simple nested composite action
+
+```
+- Job
+  - Regular Step
+  - Composite Action
+    - runs: exit 1
+    - if: always()
+      uses: A child composite action
+        - if: success()
+          runs: echo "this should print"
+        - runs: echo "this should also print"
+    - if: success()
+      runs: echo "this will not print as the current composite action has failed already"
+      
+```
+The child composite actions steps should run in this example, the child composite action has not yet failed, so it should run all steps until a step fails. This is consistent with how a composite action currently works in production if the main job fails but a composite action is invoked with `if:always()` or `if: failure()`
+
+### Other options explored
+We could add the `current_step_status` to the job context rather then `__status` to the steps context, however this comes with two major downsides:
+- We need to support the field for every type of step, because its non trivial to remove a field from the job context once it has been added (its readonly)
+  - For all actions besides composite it would only every be `success`
+  - Its weird to have a `current_step` value on the job context
+- We also explored a `__status` on the steps context.
+  - The `__` is required to prevent us from colliding with a step with id: status
+  - This felt wrong because the naming was not smooth, and did not fit into current conventions.
+
+### Consequences
+- github context has a new field for the status of the current composite action.
+- We support conditional's in composite actions
+- We keep the existing behavior for all users, but allow them to expand that functionality.

src/Runner.Worker/ActionManager.cs

@@ -1047,7 +1047,6 @@ namespace GitHub.Runner.Worker
                         }
                     }
 
-                    // TODO: remove once we remove the DistributedTask.EnableCompositeActions FF
                     foreach (var step in compositeAction.Steps)
                     {
                         if (string.IsNullOrEmpty(executionContext.Global.Variables.Get("DistributedTask.EnableCompositeActions")) && step.Reference.Type != Pipelines.ActionSourceType.Script)

src/Runner.Worker/ExecutionContext.cs

@@ -40,6 +40,7 @@ namespace GitHub.Runner.Worker
         string ScopeName { get; }
         string SiblingScopeName { get; }
         string ContextName { get; }
+        ActionRunStage Stage { get; }
         Task ForceCompleted { get; }
         TaskResult? Result { get; set; }
         TaskResult? Outcome { get; set; }
@@ -76,8 +77,8 @@ namespace GitHub.Runner.Worker
         // Initialize
         void InitializeJob(Pipelines.AgentJobRequestMessage message, CancellationToken token);
         void CancelToken();
-        IExecutionContext CreateChild(Guid recordId, string displayName, string refName, string scopeName, string contextName, Dictionary<string, string> intraActionState = null, int? recordOrder = null, IPagingLogger logger = null, bool isEmbedded = false, CancellationTokenSource cancellationTokenSource = null, Guid embeddedId = default(Guid), string siblingScopeName = null);
-        IExecutionContext CreateEmbeddedChild(string scopeName, string contextName, Guid embeddedId, Dictionary<string, string> intraActionState = null, string siblingScopeName = null);
+        IExecutionContext CreateChild(Guid recordId, string displayName, string refName, string scopeName, string contextName, ActionRunStage stage, Dictionary<string, string> intraActionState = null, int? recordOrder = null, IPagingLogger logger = null, bool isEmbedded = false, CancellationTokenSource cancellationTokenSource = null, Guid embeddedId = default(Guid), string siblingScopeName = null);
+        IExecutionContext CreateEmbeddedChild(string scopeName, string contextName, Guid embeddedId, ActionRunStage stage, Dictionary<string, string> intraActionState = null, string siblingScopeName = null);
 
         // logging
         long Write(string tag, string message);
@@ -144,6 +145,7 @@ namespace GitHub.Runner.Worker
         public string ScopeName { get; private set; }
         public string SiblingScopeName { get; private set; }
         public string ContextName { get; private set; }
+        public ActionRunStage Stage { get; private set; }
         public Task ForceCompleted => _forceCompleted.Task;
         public CancellationToken CancellationToken => _cancellationTokenSource.Token;
         public Dictionary<string, string> IntraActionState { get; private set; }
@@ -292,7 +294,7 @@ namespace GitHub.Runner.Worker
             Root.PostJobSteps.Push(step);
         }
 
-        public IExecutionContext CreateChild(Guid recordId, string displayName, string refName, string scopeName, string contextName, Dictionary<string, string> intraActionState = null, int? recordOrder = null, IPagingLogger logger = null, bool isEmbedded = false, CancellationTokenSource cancellationTokenSource = null, Guid embeddedId = default(Guid), string siblingScopeName = null)
+        public IExecutionContext CreateChild(Guid recordId, string displayName, string refName, string scopeName, string contextName, ActionRunStage stage, Dictionary<string, string> intraActionState = null, int? recordOrder = null, IPagingLogger logger = null, bool isEmbedded = false, CancellationTokenSource cancellationTokenSource = null, Guid embeddedId = default(Guid), string siblingScopeName = null)
         {
             Trace.Entering();
 
@@ -301,6 +303,7 @@ namespace GitHub.Runner.Worker
             child.Global = Global;
             child.ScopeName = scopeName;
             child.ContextName = contextName;
+            child.Stage = stage;
             child.EmbeddedId = embeddedId;
             child.SiblingScopeName = siblingScopeName;
             child.JobTelemetry = JobTelemetry;
@@ -351,9 +354,9 @@ namespace GitHub.Runner.Worker
         /// An embedded execution context shares the same record ID, record name, logger,
         /// and a linked cancellation token.
         /// </summary>
-        public IExecutionContext CreateEmbeddedChild(string scopeName, string contextName, Guid embeddedId, Dictionary<string, string> intraActionState = null, string siblingScopeName = null)
+        public IExecutionContext CreateEmbeddedChild(string scopeName, string contextName, Guid embeddedId, ActionRunStage stage, Dictionary<string, string> intraActionState = null, string siblingScopeName = null)
         {
-            return Root.CreateChild(_record.Id, _record.Name, _record.Id.ToString("N"), scopeName, contextName, logger: _logger, isEmbedded: true, cancellationTokenSource: CancellationTokenSource.CreateLinkedTokenSource(_cancellationTokenSource.Token), intraActionState: intraActionState, embeddedId: embeddedId, siblingScopeName: siblingScopeName);
+            return Root.CreateChild(_record.Id, _record.Name, _record.Id.ToString("N"), scopeName, contextName, stage, logger: _logger, isEmbedded: true, cancellationTokenSource: CancellationTokenSource.CreateLinkedTokenSource(_cancellationTokenSource.Token), intraActionState: intraActionState, embeddedId: embeddedId, siblingScopeName: siblingScopeName);
         }
 
         public void Start(string currentOperation = null)
@@ -944,7 +947,7 @@ namespace GitHub.Runner.Worker
             }
 
             var newGuid = Guid.NewGuid();
-            return CreateChild(newGuid, displayName, newGuid.ToString("N"), null, null, intraActionState, _childTimelineRecordOrder - Root.PostJobSteps.Count, siblingScopeName: siblingScopeName);
+            return CreateChild(newGuid, displayName, newGuid.ToString("N"), null, null, ActionRunStage.Post, intraActionState, _childTimelineRecordOrder - Root.PostJobSteps.Count, siblingScopeName: siblingScopeName);
         }
     }
 

src/Runner.Worker/Expressions/FailureFunction.cs

@@ -24,8 +24,19 @@ namespace GitHub.Runner.Worker.Expressions
             ArgUtil.NotNull(templateContext, nameof(templateContext));
             var executionContext = templateContext.State[nameof(IExecutionContext)] as IExecutionContext;
             ArgUtil.NotNull(executionContext, nameof(executionContext));
-            ActionResult jobStatus = executionContext.JobContext.Status ?? ActionResult.Success;
-            return jobStatus == ActionResult.Failure;
+
+            // Decide based on 'action_status' for composite MAIN steps and 'job.status' for pre, post and job-level steps
+            var isCompositeMainStep = executionContext.IsEmbedded && executionContext.Stage == ActionRunStage.Main;
+            if (isCompositeMainStep)
+            {
+                ActionResult actionStatus = EnumUtil.TryParse<ActionResult>(executionContext.GetGitHubContext("action_status")) ?? ActionResult.Success;
+                return actionStatus == ActionResult.Failure;
+            }
+            else
+            {
+                ActionResult jobStatus = executionContext.JobContext.Status ?? ActionResult.Success;
+                return jobStatus == ActionResult.Failure;
+            }
         }
     }
 }

src/Runner.Worker/Expressions/SuccessFunction.cs

@@ -24,8 +24,19 @@ namespace GitHub.Runner.Worker.Expressions
             ArgUtil.NotNull(templateContext, nameof(templateContext));
             var executionContext = templateContext.State[nameof(IExecutionContext)] as IExecutionContext;
             ArgUtil.NotNull(executionContext, nameof(executionContext));
-            ActionResult jobStatus = executionContext.JobContext.Status ?? ActionResult.Success;
-            return jobStatus == ActionResult.Success;
+
+            // Decide based on 'action_status' for composite MAIN steps and 'job.status' for pre, post and job-level steps
+            var isCompositeMainStep = executionContext.IsEmbedded && executionContext.Stage == ActionRunStage.Main;
+            if (isCompositeMainStep)
+            {
+                ActionResult actionStatus = EnumUtil.TryParse<ActionResult>(executionContext.GetGitHubContext("action_status")) ?? ActionResult.Success;
+                return actionStatus == ActionResult.Success;
+            }
+            else
+            {
+                ActionResult jobStatus = executionContext.JobContext.Status ?? ActionResult.Success;
+                return jobStatus == ActionResult.Success;
+            }
         }
     }
 }

src/Runner.Worker/Handlers/CompositeActionHandler.cs

@@ -125,7 +125,7 @@ namespace GitHub.Runner.Worker.Handlers
                     {
                         ArgUtil.NotNull(step, step.DisplayName);
                         var stepId = $"__{Guid.NewGuid()}";
-                        step.ExecutionContext = ExecutionContext.CreateEmbeddedChild(childScopeName, stepId, Guid.NewGuid());
+                        step.ExecutionContext = ExecutionContext.CreateEmbeddedChild(childScopeName, stepId, Guid.NewGuid(), stage);
                         embeddedSteps.Add(step);
                     }
                 }
@@ -144,7 +144,7 @@ namespace GitHub.Runner.Worker.Handlers
                     step.Stage = stage;
                     step.Condition = stepData.Condition;
                     ExecutionContext.Root.EmbeddedIntraActionState.TryGetValue(step.Action.Id, out var intraActionState);
-                    step.ExecutionContext = ExecutionContext.CreateEmbeddedChild(childScopeName, stepData.ContextName, step.Action.Id, intraActionState: intraActionState, siblingScopeName: siblingScopeName);
+                    step.ExecutionContext = ExecutionContext.CreateEmbeddedChild(childScopeName, stepData.ContextName, step.Action.Id, stage, intraActionState: intraActionState, siblingScopeName: siblingScopeName);
                     step.ExecutionContext.ExpressionValues["inputs"] = inputsData;
                     if (!String.IsNullOrEmpty(ExecutionContext.SiblingScopeName))
                     {
@@ -242,6 +242,10 @@ namespace GitHub.Runner.Worker.Handlers
                 step.ExecutionContext.ExpressionFunctions.Add(new FunctionInfo<FailureFunction>(PipelineTemplateConstants.Failure, 0, 0));
                 step.ExecutionContext.ExpressionFunctions.Add(new FunctionInfo<SuccessFunction>(PipelineTemplateConstants.Success, 0, 0));
 
+                // Set action_status to the success of the current composite action
+                var actionResult = ExecutionContext.Result?.ToActionResult() ?? ActionResult.Success;
+                step.ExecutionContext.SetGitHubContext("action_status", actionResult.ToString());
+
                 // Initialize env context
                 Trace.Info("Initialize Env context for embedded step");
 #if OS_WINDOWS
@@ -296,108 +300,100 @@ namespace GitHub.Runner.Worker.Handlers
                 CancellationTokenRegistration? jobCancelRegister = null;
                 try
                 {
-                    // For main steps just run the action
-                    if (stage == ActionRunStage.Main)
+                    // Register job cancellation call back only if job cancellation token not been fire before each step run
+                    if (!ExecutionContext.Root.CancellationToken.IsCancellationRequested)
+                    {
+                        // Test the condition again. The job was canceled after the condition was originally evaluated.
+                        jobCancelRegister = ExecutionContext.Root.CancellationToken.Register(() =>
+                        {
+                            // Mark job as cancelled
+                            ExecutionContext.Root.Result = TaskResult.Canceled;
+                            ExecutionContext.Root.JobContext.Status = ExecutionContext.Root.Result?.ToActionResult();
+                            
+                            step.ExecutionContext.Debug($"Re-evaluate condition on job cancellation for step: '{step.DisplayName}'.");
+                            var conditionReTestTraceWriter = new ConditionTraceWriter(Trace, null); // host tracing only
+                            var conditionReTestResult = false;
+                            if (HostContext.RunnerShutdownToken.IsCancellationRequested)
+                            {
+                                step.ExecutionContext.Debug($"Skip Re-evaluate condition on runner shutdown.");
+                            }
+                            else
+                            {
+                                try
+                                {
+                                    var templateEvaluator = step.ExecutionContext.ToPipelineTemplateEvaluator(conditionReTestTraceWriter);
+                                    var condition = new BasicExpressionToken(null, null, null, step.Condition);
+                                    conditionReTestResult = templateEvaluator.EvaluateStepIf(condition, step.ExecutionContext.ExpressionValues, step.ExecutionContext.ExpressionFunctions, step.ExecutionContext.ToExpressionState());
+                                }
+                                catch (Exception ex)
+                                {
+                                    // Cancel the step since we get exception while re-evaluate step condition
+                                    Trace.Info("Caught exception from expression when re-test condition on job cancellation.");
+                                    step.ExecutionContext.Error(ex);
+                                }
+                            }
+
+                            if (!conditionReTestResult)
+                            {
+                                // Cancel the step
+                                Trace.Info("Cancel current running step.");
+                                step.ExecutionContext.CancelToken();
+                            }
+                        });
+                    }
+                    else
+                    {
+                        if (ExecutionContext.Root.Result != TaskResult.Canceled)
+                        {
+                            // Mark job as cancelled
+                            ExecutionContext.Root.Result = TaskResult.Canceled;
+                            ExecutionContext.Root.JobContext.Status = ExecutionContext.Root.Result?.ToActionResult();
+                        }
+                    }
+                    // Evaluate condition
+                    step.ExecutionContext.Debug($"Evaluating condition for step: '{step.DisplayName}'");
+                    var conditionTraceWriter = new ConditionTraceWriter(Trace, step.ExecutionContext);
+                    var conditionResult = false;
+                    var conditionEvaluateError = default(Exception);
+                    if (HostContext.RunnerShutdownToken.IsCancellationRequested)
+                    {
+                        step.ExecutionContext.Debug($"Skip evaluate condition on runner shutdown.");
+                    }
+                    else
+                    {
+                        try
+                        {
+                            var templateEvaluator = step.ExecutionContext.ToPipelineTemplateEvaluator(conditionTraceWriter);
+                            var condition = new BasicExpressionToken(null, null, null, step.Condition);
+                            conditionResult = templateEvaluator.EvaluateStepIf(condition, step.ExecutionContext.ExpressionValues, step.ExecutionContext.ExpressionFunctions, step.ExecutionContext.ToExpressionState());
+                        }
+                        catch (Exception ex)
+                        {
+                            Trace.Info("Caught exception from expression.");
+                            Trace.Error(ex);
+                            conditionEvaluateError = ex;
+                        }
+                    }
+                    if (!conditionResult && conditionEvaluateError == null)
+                    {
+                        // Condition is false
+                        Trace.Info("Skipping step due to condition evaluation.");
+                        step.ExecutionContext.Result = TaskResult.Skipped;
+                        continue;
+                    }
+                    else if (conditionEvaluateError != null)
+                    {
+                        // Condition error
+                        step.ExecutionContext.Error(conditionEvaluateError);
+                        step.ExecutionContext.Result = TaskResult.Failed;
+                        ExecutionContext.Result = TaskResult.Failed;
+                        break;
+                    }
+                    else
                     {
                         await RunStepAsync(step);
                     }
-                    // We need to evaluate conditions for pre/post steps
-                    else
-                    {
-                        // Register job cancellation call back only if job cancellation token not been fire before each step run
-                        if (!ExecutionContext.Root.CancellationToken.IsCancellationRequested)
-                        {
-                            // Test the condition again. The job was canceled after the condition was originally evaluated.
-                            jobCancelRegister = ExecutionContext.Root.CancellationToken.Register(() =>
-                            {
-                                // Mark job as cancelled
-                                ExecutionContext.Root.Result = TaskResult.Canceled;
-                                ExecutionContext.Root.JobContext.Status = ExecutionContext.Root.Result?.ToActionResult();
-
-                                step.ExecutionContext.Debug($"Re-evaluate condition on job cancellation for step: '{step.DisplayName}'.");
-                                var conditionReTestTraceWriter = new ConditionTraceWriter(Trace, null); // host tracing only
-                                var conditionReTestResult = false;
-                                if (HostContext.RunnerShutdownToken.IsCancellationRequested)
-                                {
-                                    step.ExecutionContext.Debug($"Skip Re-evaluate condition on runner shutdown.");
-                                }
-                                else
-                                {
-                                    try
-                                    {
-                                        var templateEvaluator = step.ExecutionContext.ToPipelineTemplateEvaluator(conditionReTestTraceWriter);
-                                        var condition = new BasicExpressionToken(null, null, null, step.Condition);
-                                        conditionReTestResult = templateEvaluator.EvaluateStepIf(condition, step.ExecutionContext.ExpressionValues, step.ExecutionContext.ExpressionFunctions, step.ExecutionContext.ToExpressionState());
-                                    }
-                                    catch (Exception ex)
-                                    {
-                                        // Cancel the step since we get exception while re-evaluate step condition
-                                        Trace.Info("Caught exception from expression when re-test condition on job cancellation.");
-                                        step.ExecutionContext.Error(ex);
-                                    }
-                                }
-
-                                if (!conditionReTestResult)
-                                {
-                                    // Cancel the step
-                                    Trace.Info("Cancel current running step.");
-                                    step.ExecutionContext.CancelToken();
-                                }
-                            });
-                        }
-                        else
-                        {
-                            if (ExecutionContext.Root.Result != TaskResult.Canceled)
-                            {
-                                // Mark job as cancelled
-                                ExecutionContext.Root.Result = TaskResult.Canceled;
-                                ExecutionContext.Root.JobContext.Status = ExecutionContext.Root.Result?.ToActionResult();
-                            }
-                        }
-                        // Evaluate condition
-                        step.ExecutionContext.Debug($"Evaluating condition for step: '{step.DisplayName}'");
-                        var conditionTraceWriter = new ConditionTraceWriter(Trace, step.ExecutionContext);
-                        var conditionResult = false;
-                        var conditionEvaluateError = default(Exception);
-                        if (HostContext.RunnerShutdownToken.IsCancellationRequested)
-                        {
-                            step.ExecutionContext.Debug($"Skip evaluate condition on runner shutdown.");
-                        }
-                        else
-                        {
-                            try
-                            {
-                                var templateEvaluator = step.ExecutionContext.ToPipelineTemplateEvaluator(conditionTraceWriter);
-                                var condition = new BasicExpressionToken(null, null, null, step.Condition);
-                                conditionResult = templateEvaluator.EvaluateStepIf(condition, step.ExecutionContext.ExpressionValues, step.ExecutionContext.ExpressionFunctions, step.ExecutionContext.ToExpressionState());
-                            }
-                            catch (Exception ex)
-                            {
-                                Trace.Info("Caught exception from expression.");
-                                Trace.Error(ex);
-                                conditionEvaluateError = ex;
-                            }
-                        }
-                        if (!conditionResult && conditionEvaluateError == null)
-                        {
-                            // Condition is false
-                            Trace.Info("Skipping step due to condition evaluation.");
-                            step.ExecutionContext.Result = TaskResult.Skipped;
-                            continue;
-                        }
-                        else if (conditionEvaluateError != null)
-                        {
-                            // Condition error
-                            step.ExecutionContext.Error(conditionEvaluateError);
-                            step.ExecutionContext.Result = TaskResult.Failed;
-                            ExecutionContext.Result = TaskResult.Failed;
-                            break;
-                        }
-                        else
-                        {
-                            await RunStepAsync(step);
-                        }
-                    }
+                
                 }
                 finally
                 {
@@ -413,12 +409,6 @@ namespace GitHub.Runner.Worker.Handlers
                 {
                     Trace.Info($"Update job result with current composite step result '{step.ExecutionContext.Result}'.");
                     ExecutionContext.Result = TaskResultUtil.MergeTaskResults(ExecutionContext.Result, step.ExecutionContext.Result.Value);
-
-                    // We should run cleanup even if one of the cleanup step fails
-                    if (stage != ActionRunStage.Post)
-                    {
-                        break;
-                    }
                 }
             }
         }

src/Runner.Worker/JobExtension.cs

@@ -55,7 +55,7 @@ namespace GitHub.Runner.Worker
             ArgUtil.NotNull(message, nameof(message));
 
             // Create a new timeline record for 'Set up job'
-            IExecutionContext context = jobContext.CreateChild(Guid.NewGuid(), "Set up job", $"{nameof(JobExtension)}_Init", null, null);
+            IExecutionContext context = jobContext.CreateChild(Guid.NewGuid(), "Set up job", $"{nameof(JobExtension)}_Init", null, null, ActionRunStage.Pre);
 
             List<IStep> preJobSteps = new List<IStep>();
             List<IStep> jobSteps = new List<IStep>();
@@ -306,13 +306,13 @@ namespace GitHub.Runner.Worker
                             JobExtensionRunner extensionStep = step as JobExtensionRunner;
                             ArgUtil.NotNull(extensionStep, extensionStep.DisplayName);
                             Guid stepId = Guid.NewGuid();
-                            extensionStep.ExecutionContext = jobContext.CreateChild(stepId, extensionStep.DisplayName, null, null, stepId.ToString("N"));
+                            extensionStep.ExecutionContext = jobContext.CreateChild(stepId, extensionStep.DisplayName, null, null, stepId.ToString("N"), ActionRunStage.Pre);
                         }
                         else if (step is IActionRunner actionStep)
                         {
                             ArgUtil.NotNull(actionStep, step.DisplayName);
                             Guid stepId = Guid.NewGuid();
-                            actionStep.ExecutionContext = jobContext.CreateChild(stepId, actionStep.DisplayName, stepId.ToString("N"), null, null, intraActionStates[actionStep.Action.Id]);
+                            actionStep.ExecutionContext = jobContext.CreateChild(stepId, actionStep.DisplayName, stepId.ToString("N"), null, null, ActionRunStage.Pre, intraActionStates[actionStep.Action.Id]);
                         }
                     }
 
@@ -323,7 +323,7 @@ namespace GitHub.Runner.Worker
                         {
                             ArgUtil.NotNull(actionStep, step.DisplayName);
                             intraActionStates.TryGetValue(actionStep.Action.Id, out var intraActionState);
-                            actionStep.ExecutionContext = jobContext.CreateChild(actionStep.Action.Id, actionStep.DisplayName, actionStep.Action.Name, null, actionStep.Action.ContextName, intraActionState);
+                            actionStep.ExecutionContext = jobContext.CreateChild(actionStep.Action.Id, actionStep.DisplayName, actionStep.Action.Name, null, actionStep.Action.ContextName, ActionRunStage.Main, intraActionState);
                         }
                     }
 
@@ -394,7 +394,7 @@ namespace GitHub.Runner.Worker
             ArgUtil.NotNull(jobContext, nameof(jobContext));
 
             // create a new timeline record node for 'Finalize job'
-            IExecutionContext context = jobContext.CreateChild(Guid.NewGuid(), "Complete job", $"{nameof(JobExtension)}_Final", null, null);
+            IExecutionContext context = jobContext.CreateChild(Guid.NewGuid(), "Complete job", $"{nameof(JobExtension)}_Final", null, null, ActionRunStage.Post);
             using (var register = jobContext.CancellationToken.Register(() => { context.CancelToken(); }))
             {
                 try

src/Runner.Worker/action_yaml.json

@@ -123,6 +123,7 @@
                 "properties": {
                     "name": "string-steps-context",
                     "id": "non-empty-string",
+                    "if": "step-if",
                     "run": {
                         "type": "string-steps-context",
                         "required": true
@@ -141,6 +142,7 @@
                 "properties": {
                     "name": "string-steps-context",
                     "id": "non-empty-string",
+                    "if": "step-if",
                     "uses": {
                         "type": "non-empty-string",
                         "required": true
@@ -216,6 +218,24 @@
                 "loose-value-type": "string"
             }
         },
+        "step-if": {
+            "context": [
+              "github",
+              "inputs",
+              "strategy",
+              "matrix",
+              "steps",
+              "job",
+              "runner",
+              "env",
+              "always(0,0)",
+              "failure(0,0)",
+              "cancelled(0,0)",
+              "success(0,0)",
+              "hashFiles(1,255)"
+            ],
+            "string": {}
+        },
         "step-with": {
             "context": [
                 "github",

src/Sdk/DTPipelines/Pipelines/ObjectTemplating/PipelineTemplateConverter.cs

@@ -638,6 +638,7 @@ namespace GitHub.DistributedTask.Pipelines.ObjectTemplating
             new NamedValueInfo<NoOperationNamedValue>(PipelineTemplateConstants.Matrix),
             new NamedValueInfo<NoOperationNamedValue>(PipelineTemplateConstants.Steps),
             new NamedValueInfo<NoOperationNamedValue>(PipelineTemplateConstants.GitHub),
+            new NamedValueInfo<NoOperationNamedValue>(PipelineTemplateConstants.Inputs),
             new NamedValueInfo<NoOperationNamedValue>(PipelineTemplateConstants.Job),
             new NamedValueInfo<NoOperationNamedValue>(PipelineTemplateConstants.Runner),
             new NamedValueInfo<NoOperationNamedValue>(PipelineTemplateConstants.Env),

src/Test/L0/Worker/ActionManifestManagerL0.cs

@@ -626,6 +626,32 @@ namespace GitHub.Runner.Common.Tests.Worker
             {
                 Teardown();
             }
+        }        
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void Load_ConditionalCompositeAction()
+        {
+            try
+            {
+                //Arrange
+                Setup();
+
+                var actionManifest = new ActionManifestManager();
+                actionManifest.Initialize(_hc);
+
+                //Act
+                var result = actionManifest.Load(_ec.Object, Path.Combine(TestUtil.GetTestDataPath(), "conditional_composite_action.yml"));
+
+                //Assert
+                Assert.Equal("Conditional Composite", result.Name);
+                Assert.Equal(ActionExecutionType.Composite, result.Execution.ExecutionType);
+            }
+            finally
+            {
+                Teardown();
+            }
         }
 
         [Fact]

src/Test/L0/Worker/ExecutionContextL0.cs

@@ -193,9 +193,9 @@ namespace GitHub.Runner.Common.Tests.Worker
                 // Act.
                 jobContext.InitializeJob(jobRequest, CancellationToken.None);
 
-                var action1 = jobContext.CreateChild(Guid.NewGuid(), "action_1", "action_1", null, null);
+                var action1 = jobContext.CreateChild(Guid.NewGuid(), "action_1", "action_1", null, null, 0);
                 action1.IntraActionState["state"] = "1";
-                var action2 = jobContext.CreateChild(Guid.NewGuid(), "action_2", "action_2", null, null);
+                var action2 = jobContext.CreateChild(Guid.NewGuid(), "action_2", "action_2", null, null, 0);
                 action2.IntraActionState["state"] = "2";
 
 
@@ -291,8 +291,8 @@ namespace GitHub.Runner.Common.Tests.Worker
                 // Act.
                 jobContext.InitializeJob(jobRequest, CancellationToken.None);
 
-                var action1 = jobContext.CreateChild(Guid.NewGuid(), "action_1_pre", "action_1_pre", null, null);
-                var action2 = jobContext.CreateChild(Guid.NewGuid(), "action_1_main", "action_1_main", null, null);
+                var action1 = jobContext.CreateChild(Guid.NewGuid(), "action_1_pre", "action_1_pre", null, null, 0);
+                var action2 = jobContext.CreateChild(Guid.NewGuid(), "action_1_main", "action_1_main", null, null, 0);
 
                 var actionId = Guid.NewGuid();
                 var postRunner1 = hc.CreateService<IActionRunner>();

src/Test/L0/Worker/Expressions/ConditionFunctionsL0.cs

@@ -105,6 +105,36 @@ namespace GitHub.Runner.Common.Tests.Worker.Expressions
             }
         }
 
+        [Theory]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        [InlineData(ActionResult.Failure, ActionResult.Failure, true)]
+        [InlineData(ActionResult.Failure, ActionResult.Success, false)]
+        [InlineData(ActionResult.Success, ActionResult.Failure, true)]
+        [InlineData(ActionResult.Success, ActionResult.Success, false)]
+        [InlineData(ActionResult.Success, null, false)]
+        public void FailureFunctionComposite(ActionResult jobStatus, ActionResult? actionStatus, bool expected)
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange
+
+                var executionContext = InitializeExecutionContext(hc);
+                executionContext.Setup(x => x.GetGitHubContext("action_status")).Returns(actionStatus.ToString());
+                executionContext.Setup( x=> x.IsEmbedded).Returns(true);
+                executionContext.Setup( x=> x.Stage).Returns(ActionRunStage.Main);
+
+                _jobContext.Status = jobStatus;
+
+                // Act.
+                bool actual = Evaluate("failure()");
+
+                // Assert.
+                Assert.Equal(expected, actual);
+
+            }
+        }
+
         [Fact]
         [Trait("Level", "L0")]
         [Trait("Category", "Worker")]
@@ -134,12 +164,43 @@ namespace GitHub.Runner.Common.Tests.Worker.Expressions
             }
         }
 
+
+        [Theory]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        [InlineData(ActionResult.Failure, ActionResult.Failure, false)]
+        [InlineData(ActionResult.Failure, ActionResult.Success, true)]
+        [InlineData(ActionResult.Success, ActionResult.Failure, false)]
+        [InlineData(ActionResult.Success, ActionResult.Success, true)]
+        [InlineData(ActionResult.Success, null, true)]
+        public void SuccessFunctionComposite(ActionResult jobStatus, ActionResult? actionStatus, bool expected)
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange
+
+                var executionContext = InitializeExecutionContext(hc);
+                executionContext.Setup(x => x.GetGitHubContext("action_status")).Returns(actionStatus.ToString());
+                executionContext.Setup( x=> x.IsEmbedded).Returns(true);
+                executionContext.Setup( x=> x.Stage).Returns(ActionRunStage.Main);
+
+                _jobContext.Status = jobStatus;
+
+                // Act.
+                bool actual = Evaluate("success()");
+
+                // Assert.
+                Assert.Equal(expected, actual);
+
+            }
+        }
+
         private TestHostContext CreateTestContext([CallerMemberName] String testName = "")
         {
             return new TestHostContext(this, testName);
         }
 
-        private void InitializeExecutionContext(TestHostContext hc)
+        private Mock<IExecutionContext> InitializeExecutionContext(TestHostContext hc)
         {
             _jobContext = new JobContext();
 
@@ -149,6 +210,8 @@ namespace GitHub.Runner.Common.Tests.Worker.Expressions
 
             _templateContext = new TemplateContext();
             _templateContext.State[nameof(IExecutionContext)] = executionContext.Object;
+
+            return executionContext;
         }
 
         private bool Evaluate(string expression)

src/Test/TestData/conditional_composite_action.yml

@@ -0,0 +1,49 @@
+
+name: 'Conditional Composite'
+description: 'Test composite run step conditionals'
+inputs:
+  exit-code:
+    description: 'Action fails if set to non-zero'
+    default: '0'
+outputs:
+  default:
+    description: "Did step run with default?"
+    value: ${{ steps.default-conditional.outputs.default }}
+  success:
+    description: "Did step run with success?"
+    value: ${{ steps.success-conditional.outputs.success }}
+  failure:
+    description: "Did step run with failure?"
+    value: ${{ steps.failure-conditional.outputs.failure }}
+  always:
+    description: "Did step run with always?"
+    value: ${{ steps.always-conditional.outputs.always }}
+
+runs:
+    using: "composite"
+    steps:
+      - run: exit ${{ inputs.exit-code }}
+        shell: bash
+
+      - run: echo "::set-output name=default::true"
+        id: default-conditional
+        shell: bash
+
+      - run: echo "::set-output name=success::true"
+        id: success-conditional
+        shell: bash
+        if: success()
+
+      - run: echo "::set-output name=failure::true"
+        id: failure-conditional
+        shell: bash
+        if: failure()
+
+      - run: echo "::set-output name=always::true"
+        id: always-conditional
+        shell: bash
+        if: always()
+
+      - run: echo "failed"
+        shell: bash
+        if: ${{ inputs.exit-code == 1 && failure() }}