feat(cache): dynamodb implementation (#953)

Signed-off-by: Catalin Hofnar <catalin.hofnar@gmail.com>

test/blackbox/helpers_cloud.bash

@@ -0,0 +1,44 @@
+ROOT_DIR=$(git rev-parse --show-toplevel)
+OS="${OS:-linux}"
+ARCH="${ARCH:-amd64}"
+ZOT_PATH=${ROOT_DIR}/bin/zot-${OS}-${ARCH}
+
+
+function verify_prerequisites {
+    if [ ! -f ${ZOT_PATH} ]; then
+        echo "you need to build ${ZOT_PATH} before running the tests" >&3
+        return 1
+    fi
+
+    if [ ! command -v skopeo &> /dev/null ]; then
+        echo "you need to install skopeo as a prerequisite to running the tests" >&3
+        return 1
+    fi
+
+    if [ ! command -v awslocal ] &>/dev/null; then
+        echo "you need to install aws cli as a prerequisite to running the tests" >&3
+        return 1
+    fi
+
+    return 0
+}
+
+function zot_serve_strace() {
+    local config_file=${1}
+    strace -o "strace.txt" -f -e trace=openat ${ZOT_PATH} serve ${config_file} &
+}
+
+function zot_stop() {
+    pkill zot
+}
+
+function wait_zot_reachable() {
+    zot_url=${1}
+    curl --connect-timeout 3 \
+        --max-time 3 \
+        --retry 10 \
+        --retry-delay 0 \
+        --retry-max-time 60 \
+        --retry-connrefused \
+        ${zot_url}
+}