**Description**

I have noticed that the stable REST API doesn't have the ability to run a task (which is possible from the airflow web interface.
I think it would be nice to have either:
- Run task 
- Run all failing tasks (rerun from point of failure)
this ability for integrations.

**Use case / motivation**

I would like the ability to identify the failing tasks on a specific DAG Run and rerun only them.
I would like to do it remotely (non-interactive) using the REST API.
I could write a script that run only the failing tasks, but I couldn't find a way to "Run" a task, when I have the task instance ID.

**Are you willing to submit a PR?**

Not at this stage

**Related Issues**



airflow/models/dag.py
new_start = self.previous_schedule(last_start)
            if self.start_date:
                if new_start >= self.start_date:
                    self.start_date = new_start
            else:
                self.start_date = new_start
        next_run_date = None
        if not date_last_automated_dagrun:
            
            task_start_dates = [t.start_date for t in self.tasks if t.start_date]
            if task_start_dates:
                next_run_date = self.normalize_schedule(min(task_start_dates))
                self.log.debug("Next run date based on tasks %s", next_run_date)
        else:
            next_run_date = self.following_schedule(date_last_automated_dagrun)
        if date_last_automated_dagrun and next_run_date:
            while next_run_date <= date_last_automated_dagrun:
                next_run_date = self.following_schedule(next_run_date)
        
        if self.start_date:
            next_run_date = self.start_date if not next_run_date else max(next_run_date, self.start_date)
            if next_run_date == self.start_date:
                next_run_date = self.normalize_schedule(self.start_date)
            self.log.debug("Dag start date: %s. Next run date: %s", self.start_date, next_run_date)
        
        if next_run_date and self.end_date and next_run_date > self.end_date:
            return None
        
        
        task_end_dates = [t.end_date for t in self.tasks if t.end_date]