Update Vagrantfile for testing SELinux

`vagrant up` will build and install containerd and all dependencies,
setting up proper SELinux contexts on the runc and containerd binaries.
The VM is configured to be SELinux Enforcing by default but this gets
changed during various CI passes via a matrix param to Disabled and
Permissive before running tests. I have an open PR to fix the
container-selinux policy for containerd at
https://github.com/containers/container-selinux/pull/98 which once
accepted we will want to update the CI matrix to use Enforcing mode
instead of Permissive.

All tests currently pass in SELinux permissive mode with containerd
configured with `enable_selinux=true`. To see which tests are failing
with SELinux enforcing and an already spun up VM:
`SELINUX=Enforcing vagrant up --provision-with=selinux,test-cri`
To test SELinux enforcing in a new VM:
`vagrant destroy -force; SELINUX=Enforcing vagrant up --provision-with=shell,selinux,test-cri`

The `selinux` shell provisioner, parameterized by the SELINUX envvar,
will configure the system as you would expect, with the side effect that
containerd is configured with `enable_selinux=true` via
`/etc/containerd/config.toml` for Permissive or Enforcing modes and
`enable_selinux=false` when SELINUX=Disabled.

Provided that virtualization is suported, this Vagrantfile and provisioners
make it easy to test containerd/cri for conformance under SELinux on
non-SELinux systems.

Signed-off-by: Jacob Blain Christen <jacob@rancher.com>

script/setup/config-containerd

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+
+#   Copyright The containerd Authors.
+
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+
+#       http://www.apache.org/licenses/LICENSE-2.0
+
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+#
+# establishes /etc/containerd/config.toml
+# parameterized by the current SELinux mode
+#
+set -eux -o pipefail
+
+enable_selinux=false
+
+if type -p getenforce &>/dev/null && [[ $(getenforce) != Disabled ]]; then
+  enable_selinux=true
+fi
+
+mkdir -p /etc/containerd
+
+cat << EOF | sudo tee /etc/containerd/config.toml
+version = 2
+[plugins]
+  [plugins."io.containerd.grpc.v1.cri"]
+    enable_selinux = ${enable_selinux}
+EOF

script/setup/config-selinux

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+
+#   Copyright The containerd Authors.
+
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+
+#       http://www.apache.org/licenses/LICENSE-2.0
+
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+#
+# set the desired SELinux mode via envvar
+#
+set -eux -o pipefail
+
+if ! type -p getenforce setenforce &>/dev/null; then
+  echo SELinux is Disabled
+  exit 0
+fi
+
+case "${SELINUX}" in
+  Disabled)
+    if mountpoint -q /sys/fs/selinux; then
+      setenforce 0
+      umount -v /sys/fs/selinux
+    fi
+    ;;
+  Enforcing)
+    mountpoint -q /sys/fs/selinux || mount -o rw,relatime -t selinuxfs selinuxfs /sys/fs/selinux
+    setenforce 1
+    ;;
+  Permissive)
+    mountpoint -q /sys/fs/selinux || mount -o rw,relatime -t selinuxfs selinuxfs /sys/fs/selinux
+    setenforce 0
+    ;;
+  *)
+    echo "SELinux mode not supported: ${SELINUX}" >&2
+    exit 1
+    ;;
+esac
+
+echo SELinux is $(getenforce)

script/setup/install-critools

@@ -27,3 +27,6 @@ cd "$GOPATH"/src/github.com/kubernetes-sigs/cri-tools
 git checkout $CRITEST_COMMIT
 make
 sudo make install
+cat << EOF | sudo tee /etc/crictl.yaml
+runtime-endpoint: unix:///run/containerd/containerd.sock
+EOF

script/setup/install-runc

@@ -36,7 +36,7 @@ function install_crun() {
 	chmod +x /usr/local/sbin/runc
 }
 
-: ${RUNC_FLAVOR=runc}
+: ${RUNC_FLAVOR:=runc}
 case ${RUNC_FLAVOR} in
 runc) install_runc ;;
 crun) install_crun ;;