task.yaml

summary: Check that snap download resumes after interruption

details: |
    Verify that when a snap download is interrupted mid-way, the partial
    download file is preserved and the subsequent download attempt resumes
    from where it left off using an HTTP Range header.

    The test uses the fakestore debug endpoint to force-kill the TCP
    connection after a configured number of bytes have been served,
    simulating a network interruption during download.

# ubuntu-14.04: systemd-run not supported
# ubuntu-core: needs curl
# TODO implement fakestore CLI for debug API calls
systems: [-ubuntu-14.04*, -ubuntu-core-*]

kill-timeout: 5m

environment:
    BLOB_DIR: $(pwd)/fake-store-blobdir

skip:
    - reason: This test needs test keys to be trusted
      if: |
        [ "$TRUST_TEST_KEYS" = "false" ]

restore: |
    snap remove --purge test-snap-resume || true
    "$TESTSTOOLS"/store-state teardown-fake-store "$BLOB_DIR"
    rm -rf test-snap test-snap-resume_1.0_all.snap
    rm -f /var/lib/snapd/snaps/test-snap-resume_*.snap.partial

debug: |
    ls -la /var/lib/snapd/snaps/test-snap-resume_* 2>/dev/null || true
    "$TESTSTOOLS"/journal-state get-log -u fakestore | tail -50 || true

execute: |
    "$TESTSTOOLS"/store-state setup-fake-store "$BLOB_DIR"

    snap ack "$TESTSLIB/assertions/testrootorg-store.account-key"

    # Create a snap large enough for partial download testing.
    # The snap needs to span multiple HTTP write chunks (~32KB each)
    # so the fakestore kill-after mechanism can interrupt mid-transfer.
    mkdir -p test-snap/meta
    cat > test-snap/meta/snap.yaml << 'EOF'
    name: test-snap-resume
    version: 1.0
    summary: Test snap for download resume
    description: A test snap with padding data for resume testing
    EOF
    # Using urandom data ensures squashfs cannot compress it away
    dd if=/dev/urandom of=test-snap/data.bin bs=1M count=100 2>/dev/null
    snap pack test-snap

    snap_file="test-snap-resume_1.0_all.snap"
    snap_size=$(stat -c %s "$snap_file")
    echo "Snap file size: $snap_size"

    "$TESTSTOOLS"/store-state make-snap-installable "$BLOB_DIR" "$snap_file"

    # Tell the fakestore to kill the download connection after 20MB.
    # This ensures some successful write chunks are delivered before the
    # connection is severed, leaving a meaningful partial file.
    kill_after=20971520
    curl --fail -s -X POST http://localhost:11028/debug \
        -d "{\"action\":\"kill-request\",\"kill-path\":\"/download/$snap_file\",\"kill-after\":$kill_after}"

    echo "First install attempt: expect failure due to interrupted download"
    not snap install test-snap-resume

    # Confirm the fakestore actually killed the connection
    "$TESTSTOOLS"/journal-state get-log -u fakestore | MATCH "/download/$snap_file was force killed, quota exceeded"

    # Verify a partial download file was preserved.
    # The fakestore assigns revision 1 by default.
    partial_path="/var/lib/snapd/snaps/test-snap-resume_1.snap.partial"
    test -f "$partial_path"

    partial_size=$(stat -c %s "$partial_path")
    test "$partial_size" -gt 0
    test "$partial_size" -lt "$snap_size"
    echo "Partial download preserved: $partial_size bytes of $snap_size total"
    partial_inode="$(stat -c '%i' "$partial_path")"
    mod_time="$(stat -c '%y' "$partial_path")"

    # Reset error injection
    curl --fail -s -X POST http://localhost:11028/debug \
        -d "{\"action\":\"reset\"}"

    # Make sure the logs for the fakestore are not polluted by previous snapd download
    # retries starting from last cursor.
    cursor=$("$TESTSTOOLS"/journal-state get-last-cursor)

    echo "Second install attempt: expect success with resumed download"
    snap install test-snap-resume

    # Verify the fakestore received a Range header on the resumed download,
    # confirming that snapd resumed from the partial file offset
    "$TESTSTOOLS"/journal-state get-log-from-cursor "$cursor" -u fakestore | MATCH "/download/$snap_file range request"

    # Verify snap is installed
    snap list test-snap-resume

    complete_path="/var/lib/snapd/snaps/test-snap-resume_1.snap"
    test -f "$complete_path"
    complete_inode="$(stat -c '%i' "$complete_path")"
    complete_mod_time="$(stat -c '%y' "$complete_path")"
    # same inode proves, file was renamed, not removed an recreated
    test "$partial_inode" = "$complete_inode"
    test "$mod_time" != "$complete_mod_time"