test/system: Make tests non-destructive

This allows to run the test suite without having to worry about blasting
the whole local state of Podman.

This is done by creating a configuration file with a custom path for the
storage of Podman and specifying the config file using an env var.

The used location for the temporary storage is located either under
XDG_CACHE_HOME and if the one is not defined, $HOME/.cache is used
instead. The data are namespaced. This follows the XDG Base Directory
Specification[0]. Other locations could be /tmp or /run but those
locations usually use tmpfs and that filesystem can not be used by
Podman[1] due to missing features in tmpfs.

https://github.com/containers/toolbox/pull/818

[0] https://specifications.freedesktop.org/basedir-spec/latest/index.html
[1] https://github.com/containers/podman/issues/10693#issuecomment-863007516

test/system/000-setup.bats

@@ -3,6 +3,8 @@
 load 'libs/helpers'
 
 @test "test suite: Setup" {
+    # Setup container storage paths
+    setup_containers_store
     # Cache the default image for the system
     _pull_and_cache_distro_image $(get_system_id) $(get_system_version) || die
     # Cache all images that will be needed during the tests

test/system/100-root.bats

@@ -6,6 +6,7 @@ load 'libs/helpers'
 
 setup() {
   check_xdg_runtime_dir
+  setup_containers_store  
   cleanup_containers
 }
 

test/system/101-create.bats

@@ -6,6 +6,7 @@ load 'libs/helpers'
 
 setup() {
   check_xdg_runtime_dir
+  setup_containers_store
   cleanup_containers
 }
 

test/system/102-list.bats

@@ -6,6 +6,7 @@ load 'libs/helpers'
 
 setup() {
   check_xdg_runtime_dir
+  setup_containers_store
   cleanup_all
 }
 

test/system/103-container.bats

@@ -6,6 +6,7 @@ load 'libs/helpers'
 
 setup() {
   check_xdg_runtime_dir
+  setup_containers_store
   cleanup_containers
 }
 

test/system/104-run.bats

@@ -6,6 +6,7 @@ load 'libs/helpers'
 
 setup() {
   check_xdg_runtime_dir
+  setup_containers_store
   cleanup_containers
 }
 

test/system/105-enter.bats

@@ -6,6 +6,7 @@ load 'libs/helpers'
 
 setup() {
   check_xdg_runtime_dir
+  setup_containers_store
   cleanup_containers
 }
 

test/system/106-rm.bats

@@ -6,6 +6,7 @@ load 'libs/helpers'
 
 setup() {
   check_xdg_runtime_dir
+  setup_containers_store
   cleanup_containers
 }
 

test/system/107-rmi.bats

@@ -6,6 +6,7 @@ load 'libs/helpers'
 
 setup() {
   check_xdg_runtime_dir
+  setup_containers_store
   cleanup_all
 }
 

test/system/999-teardown.bats

@@ -4,4 +4,5 @@ load 'libs/helpers'
 
 @test "test suite: Teardown" {
   _clean_cached_images
+  _clean_temporary_storage
 }

test/system/README.md

@@ -5,8 +5,8 @@ These tests are built with BATS (Bash Automated Testing System).
 The tests are meant to ensure that Toolbox's functionality remains stable
 throughout updates of both Toolbox and Podman/libpod.
 
-**Warning**: The tests are not executed in an isolated environment. Running the
-tests will clear all podman state (delete all containers, images, etc).
+The tests are set up in a way that does not affect the host environment.
+Running them won't remove any existing containers or images.
 
 ## Dependencies
 

test/system/libs/helpers.bash

@@ -2,14 +2,19 @@
 
 load 'libs/bats-support/load'
 
+# Helpful globals
+readonly TEMP_BASE_DIR="${XDG_CACHE_HOME:-$HOME/.cache}/toolbox"
+readonly TEMP_STORAGE_DIR="${TEMP_BASE_DIR}/system-test-storage"
+
+readonly IMAGE_CACHE_DIR="${BATS_RUN_TMPDIR}/image-cache"
+readonly ROOTLESS_PODMAN_STORE_DIR="${TEMP_STORAGE_DIR}/storage"
+readonly PODMAN_STORE_CONFIG_FILE="${TEMP_STORAGE_DIR}/store.conf"
+
 # Podman and Toolbox commands to run
 readonly PODMAN=${PODMAN:-podman}
 readonly TOOLBOX=${TOOLBOX:-toolbox}
 readonly SKOPEO=$(command -v skopeo)
 
-# Helpful globals
-readonly IMAGE_CACHE_DIR="${BATS_RUN_TMPDIR}/image-cache"
-
 # Images
 declare -Ag IMAGES=([busybox]="quay.io/toolbox_tests/busybox" \
                    [fedora]="registry.fedoraproject.org/fedora-toolbox" \
@@ -26,6 +31,19 @@ function cleanup_containers() {
 }
 
 
+function _setup_containers_store() {
+  mkdir -p ${TEMP_STORAGE_DIR}
+  # Setup a storage config file for PODMAN
+  echo -e "[storage]\n  driver = \"overlay\"\n  rootless_storage_path = \"${ROOTLESS_PODMAN_STORE_DIR}\"\n" > ${PODMAN_STORE_CONFIG_FILE}
+  export CONTAINERS_STORAGE_CONF=${PODMAN_STORE_CONFIG_FILE}
+}
+
+
+function _clean_temporary_storage() {
+  rm -rf ${TEMP_STORAGE_DIR}
+}
+
+
 # Pulls an image using Podman and saves it to a image dir using Skopeo
 #
 # Parameters
@@ -133,7 +151,8 @@ function pull_distro_image() {
     return
   fi
 
-  run $SKOPEO copy "dir:${IMAGE_CACHE_DIR}/${image_archive}" "containers-storage:${image}"
+  # https://github.com/containers/skopeo/issues/547 for the options for containers-storage
+  run $SKOPEO copy "dir:${IMAGE_CACHE_DIR}/${image_archive}" "containers-storage:[overlay@$ROOTLESS_PODMAN_STORE_DIR+$ROOTLESS_PODMAN_STORE_DIR]${image}"
   if [ "$status" -ne 0 ]; then
     echo "Failed to load image ${image} from cache ${IMAGE_CACHE_DIR}/${image_archive}"
     assert_success