Correct Windows plugin restart when Reattach info is stale #6092
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The Reattach info Nomad stores can get stale, whereby the pid no longer refers to a live process. This has happened to me regularly (but not always) when troubleshooting plugin initialization and handshaking as I'm frequently starting and killing nomad. On Windows, when the go-plugin code calls FindProcess with as stale pid, the following error is always returned: os.SyscallError - 'OpenProcess: the paremter is incorrect' On Unix systems, FindProcess never returns an error, at least as presently defined in the go source code. In order for Nomad to recognize this condition we need to bubble up the ErrProcesNotFound error, with which we can then futher propogate the SingletonPluginExited error from singleton.go. With these changes in place, whenever a stale pid is found in the Reattach info, Nomad now properly restarts the plugin exe.
|
|
endocrimes
reviewed
Sep 1, 2019
| @@ -780,7 +780,10 @@ func (c *Client) reattach() (net.Addr, error) { | |||
| // Verify the process still exists. If not, then it is an error | |||
| p, err := os.FindProcess(c.config.Reattach.Pid) | |||
| if err != nil { | |||
| return nil, err | |||
| // On Unix systems, FindProcess never returns an error. | |||
There was a problem hiding this comment.
Could you please open this diff on hashicorp/go-plugin
There was a problem hiding this comment.
It is already there:
hashicorp/go-plugin#125
|
That fix to |
|
I'm going to lock this pull request because it has been closed for 120 days ⏳. This helps our maintainers find and focus on the active contributions. |
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The Reattach info Nomad stores can get stale, whereby the pid no
longer refers to a live process.
This has happened to me regularly (but not always) when
troubleshooting plugin initialization and handshaking as I'm
frequently starting and killing nomad.
On Windows, when the go-plugin code calls FindProcess with a stale
pid, the following error is always returned:
os.SyscallError - 'OpenProcess: the paremter is incorrect'
On Unix systems, FindProcess never returns an error, at least as
presently defined in the go source code.
In order for Nomad to recognize this condition we need to bubble up
the ErrProcesNotFound error, with which we can then futher propogate
the SingletonPluginExited error from singleton.go.
With these changes in place, whenever a stale pid is found in the
Reattach info, Nomad now properly restarts the plugin exe.