Merge pull request #11503 from Luap99/remote-attach

Fix conmon attach socket buffer size

2 files changed, 31 insertions, 1 deletions

diff --git a/libpod/oci_conmon_linux.go b/libpod/oci_conmon_linux.go
index 353e6af71..c00d83f95 100644
--- a/libpod/oci_conmon_linux.go
+++ b/libpod/oci_conmon_linux.go
@@ -46,7 +46,9 @@ import (
 const (
 	// This is Conmon's STDIO_BUF_SIZE. I don't believe we have access to it
 	// directly from the Go code, so const it here
-	bufferSize = conmonConfig.BufSize
+	// Important: The conmon attach socket uses an extra byte at the beginning of each
+	// message to specify the STREAM so we have to increase the buffer size by one
+	bufferSize = conmonConfig.BufSize + 1
 )
 
 // ConmonOCIRuntime is an OCI runtime managed by Conmon.
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