workdir presence checks

A container's workdir can be specified via the CLI via `--workdir` and
via an image config with the CLI having precedence.

Since images have a tendency to specify workdirs without necessarily
shipping the paths with the root FS, make sure that Podman creates the
workdir.  When specified via the CLI, do not create the path, but check
for its existence and return a human-friendly error.

NOTE: `crun` is performing a similar check that would yield exit code
127.  With this change, however, Podman performs the check and yields
exit code 126.  Since this is specific to `crun`, I do not consider it
to be a breaking change of Podman.

Fixes: #9040
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

2 files changed, 24 insertions, 1 deletions

diff --git a/test/system/030-run.bats b/test/system/030-run.bats
index 29dc95dc3..dcf1da370 100644
--- a/test/system/030-run.bats
+++ b/test/system/030-run.bats
@@ -589,4 +589,25 @@ json-file | f
     is "${lines[1]}" "$rand" "Container runs successfully despite warning"
 }
 
+@test "podman run - check workdir" {
+    # Workdirs specified via the CLI are not created on the root FS.
+    run_podman 126 run --rm --workdir /i/do/not/exist $IMAGE pwd
+    # Note: remote error prepends an attach error.
+    is "$output" "Error: .*workdir \"/i/do/not/exist\" does not exist on container.*"
+
+    testdir=$PODMAN_TMPDIR/volume
+    mkdir -p $testdir
+    randomcontent=$(random_string 10)
+    echo "$randomcontent" > $testdir/content
+
+    # Workdir does not exist on the image but is volume mounted.
+    run_podman run --rm --workdir /IamNotOnTheImage -v $testdir:/IamNotOnTheImage $IMAGE cat content
+    is "$output" "$randomcontent" "cat random content"
+
+    # Workdir does not exist on the image but is created by the runtime as it's
+    # a subdir of a volume.
+    run_podman run --rm --workdir /IamNotOntheImage -v $testdir/content:/IamNotOntheImage/foo $IMAGE cat foo
+    is "$output" "$randomcontent" "cat random content"
+}
+
 # vim: filetype=sh
diff --git a/test/system/070-build.bats b/test/system/070-build.bats
index 9e5e3ee1d..cee28658f 100644
--- a/test/system/070-build.bats
+++ b/test/system/070-build.bats
@@ -163,10 +163,12 @@ EOF
 https_proxy=https-proxy-in-env-file
 EOF
 
+    # NOTE: it's important to not create the workdir.
+    # Podman will make sure to create a missing workdir
+    # if needed. See #9040.
     cat >$tmpdir/Containerfile <<EOF
 FROM $IMAGE
 LABEL $label_name=$label_value
-RUN mkdir $workdir
 WORKDIR $workdir
 
 # Test for #7094 - chowning of invalid symlinks