From 7cf22279d9499bfb7b2688cd2a6cb71617feba6e Mon Sep 17 00:00:00 2001 From: Paul Holzinger Date: Thu, 9 Sep 2021 14:05:25 +0200 Subject: Fix conmon attach socket buffer size The conmon buffer size is 8192, however the attach socket needs two extra bytes. The first byte of each message will be the STREAM type. The last byte is a null byte. So when we want to read 8192 message bytes we need to read 8193 bytes since the first one is special. check https://github.com/containers/conmon/blob/1ef246896b4f6566964ed861b98cd32d0e7bf7a2/src/ctr_stdio.c#L101-L107 This problem can be seen in podman-remote run/exec when it prints output with 8192 or more bytes. The output will miss the 8192 byte. Fixes #11496 Signed-off-by: Paul Holzinger --- test/system/075-exec.bats | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'test') diff --git a/test/system/075-exec.bats b/test/system/075-exec.bats index 3e8c3c1ea..b7367d153 100644 --- a/test/system/075-exec.bats +++ b/test/system/075-exec.bats @@ -101,4 +101,32 @@ load helpers run_podman rm $cid } +# #11496: podman-remote loses output +@test "podman exec/run - missing output" { + local bigfile=${PODMAN_TMPDIR}/bigfile + local newfile=${PODMAN_TMPDIR}/newfile + # create a big file, bigger than the 8K buffer size + base64 /dev/urandom | head -c 20K > $bigfile + + run_podman run --rm -v $bigfile:/tmp/test:Z $IMAGE cat /tmp/test + printf "%s" "$output" > $newfile + # use cmp to compare the files, this is very helpful since it will + # tell us the first wrong byte in case this fails + run cmp $bigfile $newfile + is "$output" "" "run output is identical with the file" + + run_podman run -d --stop-timeout 0 -v $bigfile:/tmp/test:Z $IMAGE sleep inf + cid="$output" + + run_podman exec $cid cat /tmp/test + printf "%s" "$output" > $newfile + # use cmp to compare the files, this is very helpful since it will + # tell us the first wrong byte in case this fails + run cmp $bigfile $newfile + is "$output" "" "exec output is identical with the file" + + # Clean up + run_podman rm -f $cid +} + # vim: filetype=sh -- cgit v1.2.3-54-g00ecf