* test: use `T.TempDir` to create temporary test directory
This commit replaces `ioutil.TempDir` with `t.TempDir` in tests. The
directory created by `t.TempDir` is automatically removed when the test
and all its subtests complete.
Prior to this commit, temporary directory created using `ioutil.TempDir`
needs to be removed manually by calling `os.RemoveAll`, which is omitted
in some tests. The error handling boilerplate e.g.
defer func() {
if err := os.RemoveAll(dir); err != nil {
t.Fatal(err)
}
}
is also tedious, but `t.TempDir` handles this for us nicely.
Reference: https://pkg.go.dev/testing#T.TempDir
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
* test: fix TestLogmon_Start_restart on Windows
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
* test: fix failing TestConsul_Integration
t.TempDir fails to perform the cleanup properly because the folder is
still in use
testing.go:967: TempDir RemoveAll cleanup: unlinkat /tmp/TestConsul_Integration2837567823/002/191a6f1a-5371-cf7c-da38-220fe85d10e5/web/secrets: device or resource busy
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
Although this operation is safe on linux, it is not safe on Windows when
using the named pipe interface. To provide a ~reasonable common api
abstraction, here we switch to returning File exists errors on the unix
api.
On unix platforms, it is safe to re-open fifo's for reading after the
first creation if the file is already a fifo, however this is not
possible on windows where this triggers a permissions error on the
socket path, as you cannot recreate it.
We can't transparently handle this in the CreateAndRead handle, because
the Access Is Denied error is too generic to reliably be an IO error.
Instead, we add an explict API for opening a reader to an existing FIFO,
and check to see if the fifo already exists inside the calling package
(e.g logmon)
This PR switches to using plain fifo files instead of golang structs
managed by containerd/fifo library.
The library main benefit is management of opening fifo files. In Linux,
a reader `open()` request would block until a writer opens the file (and
vice-versa). The library uses goroutines so that it's the first IO
operation that blocks.
This benefit isn't really useful for us: Given that logmon simply
streams output in a separate process, blocking of opening or first read
is effectively the same.
The library additionally makes further complications for managing state
and tracking read/write permission that seems overhead for our use,
compared to using a file directly.
Looking here, I made the following incidental changes:
* document that we do handle if fifo files are already created, as we
rely on that behavior for logmon restarts
* use type system to lock read vs write: currently, fifo library returns
`io.ReadWriteCloser` even if fifo is opened for writing only!
