feat: update the way test artifacts are downloaded and used

The old setup used `build/img` as the base directory
for artifacts pulled from S3. In S3 the artifacts directory
contains 1 subdirectory per architecture (x86_64 and aarch64).
This was causing final local artifacts path to be `build/img/x86_64`
or `build/img/aarch64`.

This commit changes the structure a to have a separate `build/artifacts`
directory with subdirectories containing different versions of
artifacts. The path to currently used artifacts will be placed in
`build/current_artifacts` file. This make is easy to switch between
multiple versions of artifacts without a need to delete/download them.
This also opens a door for A/B testing of artifacts.

Signed-off-by: Egor Lazarchuk <yegorlz@amazon.co.uk>

Author: ShadowCurse

tests/README.md

@@ -452,9 +452,9 @@ there. `pytest` will bring them into scope for all your tests.
 
 `Q4:` *I want to use more/other microvm test images, but I don't want to add
 them to the common s3 bucket.*\
-`A4:` Add your custom images to the `build/img` subdirectory in the Firecracker
-source tree. This directory is bind-mounted in the container and used as a local
-image cache.
+`A4:` Add your custom images to the `build/artifacts` subdirectory in the
+Firecracker source tree. This directory is bind-mounted in the container and
+used as a local image cache.
 
 `Q5:` *How can I get live logger output from the tests?*\
 `A5:` Accessing **pytest.ini** will allow you to modify logger settings.

tests/conftest.py

@@ -22,7 +22,6 @@
 import inspect
 import json
 import os
-import platform
 import shutil
 import sys
 import tempfile
@@ -346,9 +345,13 @@ def get(self, _netns_id):
     for netns in netns_fcty._all:
         netns._cleanup_orig()
 
+@pytest.fixture(scope="session")
+def current_artifacts_path():
+    with open("/firecracker/build/current_artifacts", "r", encoding="utf-8") as ca:
+        yield ca.read().strip()
 
 @pytest.fixture()
-def microvm_factory(request, record_property, results_dir, netns_factory):
+def microvm_factory(request, record_property, results_dir, netns_factory, current_artifacts_path):
     """Fixture to create microvms simply."""
 
     binary_dir = request.config.getoption("--binary-dir") or DEFAULT_BINARY_DIR
@@ -399,7 +402,7 @@ def microvm_factory(request, record_property, results_dir, netns_factory):
             uvm_data.joinpath("host-dmesg.log").write_text(
                 utils.run_cmd(["dmesg", "-dPx"]).stdout
             )
-            shutil.copy(f"/firecracker/build/img/{platform.machine()}/id_rsa", uvm_data)
+            shutil.copy(f"{current_artifacts_path}/id_rsa", uvm_data)
             if Path(uvm.screen_log).exists():
                 shutil.copy(uvm.screen_log, uvm_data)
 

tests/framework/defs.py

@@ -32,10 +32,13 @@
 
 SUPPORTED_HOST_KERNELS = ["5.10", "6.1"]
 
-IMG_DIR = Path(DEFAULT_TEST_SESSION_ROOT_PATH) / "img"
+ARTIFACT_DIR = Path(DEFAULT_TEST_SESSION_ROOT_PATH) / "current_artifacts"
 
 # fall-back to the local directory
-if not IMG_DIR.exists():
-    IMG_DIR = LOCAL_BUILD_PATH / "img"
-
-ARTIFACT_DIR = IMG_DIR / platform.machine()
+if not ARTIFACT_DIR.exists():
+    current_artifacts_dir = (
+        open(Path(LOCAL_BUILD_PATH) / "current_artifacts", "r", encoding="utf-8")
+        .read()
+        .strip()
+    )
+    ARTIFACT_DIR = LOCAL_BUILD_PATH / current_artifacts_dir

tools/devtool

@@ -116,7 +116,11 @@ CTR_TEST_RESULTS_DIR="${CTR_FC_ROOT_DIR}/test_results"
 CTR_CARGO_TARGET_DIR="$CTR_FC_BUILD_DIR/cargo_target"
 
 # Path to the microVM images cache dir
-MICROVM_IMAGES_DIR="build/img"
+LOCAL_ARTIFACTS_DIR="build/artifacts"
+
+# File with a single line specifing the name of the
+# currently used artifacts
+LOCAL_ARTIFACTS_CURRENT_DIR_FILE="build/current_artifacts"
 
 # Full path to the public key mapping on the guest
 PUB_KEY_PATH=/root/.ssh/id_rsa.pub
@@ -138,6 +142,13 @@ DEFAULT_ARTIFACTS_S3_BUCKET=s3://spec.ccfc.min/firecracker-ci
 # Query default S3 bucket with artifacts and return the most recient path
 get_newest_s3_artifacts() {
   echo $(aws s3 ls $DEFAULT_ARTIFACTS_S3_BUCKET/ --no-sign-request | grep "PRE" | sort -k2 | tail -1 | awk -v bucket="$DEFAULT_ARTIFACTS_S3_BUCKET" '{print bucket "/" $2}')
+  # echo "s3://spec.ccfc.min/firecracker-ci/v1.15"
+}
+# Function to return local path to artifacts. Accepts the url from function above
+# as an argument.
+get_local_artifacts_path() {
+    local path=$1
+    echo $LOCAL_ARTIFACTS_DIR/"${path//\//-}"
 }
 
 
@@ -567,7 +578,7 @@ cmd_distclean() {
 
 cmd_download_ci_artifacts() {
     if [ "$1" = "--force" ]; then
-        rm -rf $FC_BUILD_DIR/img
+        rm -rf $ARTIFACTS_DIR
     fi
 
     ensure_ci_artifacts
@@ -579,15 +590,21 @@ ensure_ci_artifacts() {
     fi
 
     # Fetch all the artifacts so they are local
-    S3_URL=$(get_newest_s3_artifacts)/$(uname -m)
-    say "Fetching CI artifacts from S3: " $S3_URL
-    ARTIFACTS=$MICROVM_IMAGES_DIR/$(uname -m)
-    if [ ! -d "$ARTIFACTS" ]; then
-        mkdir -pv $ARTIFACTS
-        aws s3 sync --no-sign-request "$S3_URL" "$ARTIFACTS"
-        ok_or_die "Failed to download CI artifacts using awscli!"
-        cmd_sh "./tools/setup-ci-artifacts.sh"
+    local artifacts_s3_url=$(get_newest_s3_artifacts)
+    local artifacts_s3_url_arch=$artifacts_s3_url/$(uname -m)
+    local artifacts_local_path=$(get_local_artifacts_path $artifacts_s3_url)/$(uname -m)
+
+    if [ ! -d "$artifacts_local_path" ]; then
+        say "Fetching artifacts from S3: " $artifacts_s3_url_arch " into: " $artifacts_local_path
+        mkdir -pv $artifacts_local_path
+        aws s3 sync --no-sign-request "$artifacts_s3_url_arch" "$artifacts_local_path"
+        ok_or_die "Failed to download artifacts using awscli!"
+        cmd_sh "./tools/setup-ci-artifacts.sh" $artifacts_local_path
+    else
+        say "Found existing artifacts " $artifacts_s3_url_arch " at: " $artifacts_local_path
     fi
+
+    echo $artifacts_local_path > $LOCAL_ARTIFACTS_CURRENT_DIR_FILE
 }
 
 apply_linux_61_tweaks() {

tools/setup-ci-artifacts.sh

@@ -9,7 +9,7 @@ TOOLS_DIR=$(dirname $0)
 source "$TOOLS_DIR/functions"
 
 say "Setup CI artifacts"
-cd build/img/$(uname -m)
+cd $1
 
 say "Fix executable permissions"
 find "firecracker" -type f |xargs chmod -c 755

tools/test.sh

@@ -32,7 +32,7 @@ if [ -f $CGROUP/cgroup.controllers -a -e $CGROUP/cgroup.type ]; then
 fi
 
 say "Copy CI artifacts to /srv, so hardlinks work"
-cp -ruvf build/img /srv
+cp -ruvfL $(cat build/current_artifacts) /srv/current_artifacts
 
 cd tests
 export PYTEST_ADDOPTS="${PYTEST_ADDOPTS:-} --pdbcls=IPython.terminal.debugger:TerminalPdb"