/// <summary>Recover an already existing container.</summary>
/// <remarks>
/// Recover an already existing container. This is a blocking call and returns
/// only when the container exits. Note that the container must have been
/// activated prior to this call.
/// </remarks>
/// <param name="user">the user of the container</param>
/// <param name="containerId">The ID of the container to reacquire</param>
/// <returns>The exit code of the pre-existing container</returns>
/// <exception cref="System.IO.IOException"/>
/// <exception cref="System.Exception"></exception>
public virtual int ReacquireContainer(string user, ContainerId containerId)
{
Path pidPath = GetPidFilePath(containerId);
if (pidPath == null)
{
Log.Warn(containerId + " is not active, returning terminated error");
return(ContainerExecutor.ExitCode.Terminated.GetExitCode());
}
string pid = null;
pid = ProcessIdFileReader.GetProcessId(pidPath);
if (pid == null)
{
throw new IOException("Unable to determine pid for " + containerId);
}
Log.Info("Reacquiring " + containerId + " with pid " + pid);
while (IsContainerProcessAlive(user, pid))
{
Sharpen.Thread.Sleep(1000);
}
// wait for exit code file to appear
string exitCodeFile = ContainerLaunch.GetExitCodeFile(pidPath.ToString());
FilePath file = new FilePath(exitCodeFile);
int sleepMsec = 100;
int msecLeft = 2000;
while (!file.Exists() && msecLeft >= 0)
{
if (!IsContainerActive(containerId))
{
Log.Info(containerId + " was deactivated");
return(ContainerExecutor.ExitCode.Terminated.GetExitCode());
}
Sharpen.Thread.Sleep(sleepMsec);
msecLeft -= sleepMsec;
}
if (msecLeft < 0)
{
throw new IOException("Timeout while waiting for exit code from " + containerId);
}
try
{
return(System.Convert.ToInt32(FileUtils.ReadFileToString(file).Trim()));
}
catch (FormatException e)
{
throw new IOException("Error parsing exit code from pid " + pid, e);
}
}
/// <summary>Get the process-identifier for the container</summary>
/// <param name="containerID"/>
/// <returns>
/// the processid of the container if it has already launched,
/// otherwise return null
/// </returns>
public virtual string GetProcessId(ContainerId containerID)
{
string pid = null;
Path pidFile = pidFiles[containerID];
if (pidFile == null)
{
// This container isn't even launched yet.
return(pid);
}
try
{
pid = ProcessIdFileReader.GetProcessId(pidFile);
}
catch (IOException e)
{
Log.Error("Got exception reading pid from pid-file " + pidFile, e);
}
return(pid);
}
/// <summary>
/// Loop through for a time-bounded interval waiting to
/// read the process id from a file generated by a running process.
/// </summary>
/// <param name="pidFilePath">File from which to read the process id</param>
/// <returns>Process ID</returns>
/// <exception cref="System.Exception"/>
private string GetContainerPid(Path pidFilePath)
{
string containerIdStr = ConverterUtils.ToString(container.GetContainerId());
string processId = null;
Log.Debug("Accessing pid for container " + containerIdStr + " from pid file " + pidFilePath
);
int sleepCounter = 0;
int sleepInterval = 100;
// loop waiting for pid file to show up
// until our timer expires in which case we admit defeat
while (true)
{
processId = ProcessIdFileReader.GetProcessId(pidFilePath);
if (processId != null)
{
Log.Debug("Got pid " + processId + " for container " + containerIdStr);
break;
}
else
{
if ((sleepCounter * sleepInterval) > maxKillWaitTime)
{
Log.Info("Could not get pid for " + containerIdStr + ". Waited for " + maxKillWaitTime
+ " ms.");
break;
}
else
{
++sleepCounter;
Sharpen.Thread.Sleep(sleepInterval);
}
}
}
return(processId);
}
