/// <summary>
/// Remove unused snapshots.
/// A snapshot is considered unused if it has not been accessed for at least
/// (MDHeartbeatPeriod + MDOldSnapshotHeartbeatMargin) minutes.
/// However, the last MDMinNumberOfSnapshotsToKeep snapshots will be kept regardless
/// of the access time.
/// </summary>
public void Purge(ILogger logger)
{
var allSnapshotPaths = _storage.GetInstalledAndInstallingSnapshots();
var threshold = DateTime.UtcNow - _heartbeatPeriod - _oldHeartbeatAgeMargin;
var pathSortedByAccessTime = allSnapshotPaths
.Select(path => Tuple.Create(path, GetSnapshotAccessTimeUtc(path, logger)))
.OrderBy(entry => entry.Item2)
.ToArray();
for (var i = 0; i < pathSortedByAccessTime.Length - _minNumberOfSnapshotsToKeep; ++i)
{
var creationTime = pathSortedByAccessTime[i].Item2;
if (creationTime > threshold)
{
break;
}
var pathToRemove = pathSortedByAccessTime[i].Item1;
try
{
var message = string.Format(PowerShellWorkerStrings.RemovingDependenciesFolder, pathToRemove);
logger.Log(isUserOnlyLog: false, LogLevel.Trace, message);
_storage.RemoveSnapshot(pathToRemove);
}
catch (IOException e)
{
var message = string.Format(PowerShellWorkerStrings.FailedToRemoveDependenciesFolder, pathToRemove, e.Message);
logger.Log(isUserOnlyLog: false, LogLevel.Warning, message, e);
}
}
}
public void InstallSnapshot(
IEnumerable <DependencyManifestEntry> dependencies,
string targetPath,
PowerShell pwsh,
DependencySnapshotInstallationMode installationMode,
ILogger logger)
{
var installingPath = CreateInstallingSnapshot(targetPath);
logger.Log(
isUserOnlyLog: false,
LogLevel.Trace,
string.Format(
PowerShellWorkerStrings.InstallingFunctionAppRequiredModules,
installingPath,
installationMode));
try
{
foreach (DependencyInfo module in GetExactVersionsOfDependencies(dependencies))
{
InstallModule(module, installingPath, pwsh, logger);
}
_snapshotContentLogger.LogDependencySnapshotContent(installingPath, logger);
switch (installationMode)
{
case DependencySnapshotInstallationMode.Optional:
// If the new snapshot turns out to be equivalent to the latest one,
// removing it helps us save storage space and avoid unnecessary worker restarts.
// It is ok to do that during background upgrade because the current
// worker already has a good enough snapshot, and nothing depends on
// the new snapshot yet.
PromoteToInstalledOrRemove(installingPath, targetPath, installationMode, logger);
break;
case DependencySnapshotInstallationMode.Required:
// Even if the new snapshot turns out to be equivalent to the latest one,
// removing it would not be safe because the current worker already depends
// on it, as it has the path to this snapshot already added to PSModulePath.
// As opposed to the background upgrade case, this snapshot is *required* for
// this worker to run, even though it occupies some space (until the workers
// restart and the redundant snapshots are purged).
PromoteToInstalled(installingPath, targetPath, installationMode, logger);
break;
default:
throw new ArgumentException($"Unexpected installation mode: {installationMode}", nameof(installationMode));
}
}
catch (Exception e)
{
var message = string.Format(
PowerShellWorkerStrings.FailedToInstallDependenciesSnapshot,
targetPath,
installationMode);
logger.Log(isUserOnlyLog: false, LogLevel.Warning, message, e);
_storage.RemoveSnapshot(installingPath);
throw;
}
finally
{
_moduleProvider.Cleanup(pwsh);
}
}
public void InstallSnapshot(
IEnumerable <DependencyManifestEntry> dependencies,
string targetPath,
PowerShell pwsh,
ILogger logger)
{
logger.Log(isUserOnlyLog: false, LogLevel.Trace, PowerShellWorkerStrings.InstallingFunctionAppDependentModules);
var installingPath = CreateInstallingSnapshot(targetPath);
try
{
foreach (DependencyInfo module in GetExactVersionsOfDependencies(dependencies))
{
logger.Log(isUserOnlyLog: false, LogLevel.Trace, string.Format(PowerShellWorkerStrings.StartedInstallingModule, module.Name, module.ExactVersion));
int tries = 1;
while (true)
{
try
{
_moduleProvider.SaveModule(pwsh, module.Name, module.ExactVersion, installingPath);
var message = string.Format(PowerShellWorkerStrings.ModuleHasBeenInstalled, module.Name, module.ExactVersion);
logger.Log(isUserOnlyLog: false, LogLevel.Trace, message);
break;
}
catch (Exception e)
{
string currentAttempt = GetCurrentAttemptMessage(tries);
var errorMsg = string.Format(PowerShellWorkerStrings.FailToInstallModule, module.Name, module.ExactVersion, currentAttempt, e.Message);
logger.Log(isUserOnlyLog: false, LogLevel.Error, errorMsg);
if (tries >= MaxNumberOfTries)
{
errorMsg = string.Format(PowerShellWorkerStrings.FailToInstallFuncAppDependencies, e.Message);
throw new DependencyInstallationException(errorMsg, e);
}
}
// Wait for 2^(tries-1) seconds between retries. In this case, it would be 1, 2, and 4 seconds, respectively.
var waitTimeSpan = TimeSpan.FromSeconds(Math.Pow(2, tries - 1));
Thread.Sleep(waitTimeSpan);
tries++;
}
}
_storage.PromoteInstallingSnapshotToInstalledAtomically(targetPath);
}
catch (Exception e)
{
var message = string.Format(PowerShellWorkerStrings.FailedToInstallDependenciesSnapshot, targetPath);
logger.Log(isUserOnlyLog: false, LogLevel.Warning, message, e);
_storage.RemoveSnapshot(installingPath);
throw;
}
finally
{
_moduleProvider.Cleanup(pwsh);
}
}