benchmark.sh

#!/bin/bash

# ------------------------------------------------------------
# Configuration
# ------------------------------------------------------------
BASE_NAME="javahello"
PACKAGE_PATH="src/main/java/fr/univtln/bruno/demos/docker"

declare -A BUILDS=(
    ["01.mavenimage"]="mavenimage"
    ["02.mavenimagestage"]="mavenimagestage"
    ["03.dockercache"]="dockercache"
    ["05.manual"]="manual"
    ["06.jlink"]="jlink"
    ["06b.jlink-alpine"]="jlink-alpine"
    ["07.graalVM"]="graalvm"
)

ORDER=(
    "01.mavenimage"
    "02.mavenimagestage"
    "03.dockercache"
    "05.manual"
    "06.jlink"
    "06b.jlink-alpine"
    "07.graalVM"
)

echo "Here size means the final image size, while peak RAM is the maximum memory usage observed during runtime."
echo -e "\nBenchmark : Analyse de l'Efficience (Build vs Runtime)\n"
echo "| Image Tag | Build Cold | Build Warm | Build Incr. | Size | Peak RAM |"
echo "|:----------|:-----------|:-----------|:------------|:-----|:---------|"

for KEY in "${ORDER[@]}"; do
    TAG=${BUILDS[$KEY]}
    DOCKERFILE="Dockerfile.$KEY"
    FULL_TAG="$BASE_NAME:$TAG"

    [ ! -f "$DOCKERFILE" ] && continue

    # --------------------------------------------------------
    # 1. COLD BUILD (no cache)
    # --------------------------------------------------------
    B_START=$(date +%s)
    docker build --no-cache -t "$FULL_TAG" -f "$DOCKERFILE" . > /dev/null 2>&1
    COLD_TIME="$(( $(date +%s) - B_START ))s"

    # --------------------------------------------------------
    # 2. WARM BUILD (full cache)
    # --------------------------------------------------------
    B_START=$(date +%s)
    docker build -t "$FULL_TAG" -f "$DOCKERFILE" . > /dev/null 2>&1
    WARM_TIME="$(( $(date +%s) - B_START ))s"

    # --------------------------------------------------------
    # 3. INCREMENTAL BUILD (ServiceLoader – GraalVM aware)
    # --------------------------------------------------------
    FAKE_CLASS="Fake$(date +%s)"
    FAKE_JAVA="$PACKAGE_PATH/$FAKE_CLASS.java"

    SPI_DIR="src/main/resources/META-INF/services"
    SPI_FILE="$SPI_DIR/fr.univtln.bruno.demos.docker.Marker"

    mkdir -p "$SPI_DIR"

    cat > "$FAKE_JAVA" <<EOF
package fr.univtln.bruno.demos.docker;

public class $FAKE_CLASS implements Marker {
    @Override
    public void touch() {
        // noop
    }
}
EOF

    echo "fr.univtln.bruno.demos.docker.$FAKE_CLASS" > "$SPI_FILE"

    B_START=$(date +%s)
    docker build -t "$FULL_TAG" -f "$DOCKERFILE" . > /dev/null 2>&1
    INCR_TIME="$(( $(date +%s) - B_START ))s"

    # Nettoyage
    rm -f "$FAKE_JAVA" "$SPI_FILE"

    # --------------------------------------------------------
    # 4. RUNTIME STATS (Peak RAM via cgroups)
    # --------------------------------------------------------
    SIZE_STR=$(docker image inspect "$FULL_TAG" \
        --format '{{.Size}}' 2>/dev/null \
        | awk '{printf "%.1fMB", $1/1024/1024}')

    # Lancer le container
    CID=$(docker run -d "$FULL_TAG")
    docker wait "$CID" >/dev/null 2>&1

    # Trouver le cgroup du conteneur
    CGROUP_PATH=$(docker inspect --format '{{.Id}}' "$CID")

    # Peak RAM exact via cgroup v1 ou v2
    if [ -f "/sys/fs/cgroup/memory/docker/$CGROUP_PATH/memory.max_usage_in_bytes" ]; then
        PEAK_MEM_RAW=$(cat "/sys/fs/cgroup/memory/docker/$CGROUP_PATH/memory.max_usage_in_bytes")
    elif [ -f "/sys/fs/cgroup/docker/$CGROUP_PATH/memory.max" ]; then
        # cgroup v2
        PEAK_MEM_RAW=$(cat "/sys/fs/cgroup/docker/$CGROUP_PATH/memory.max")
    else
        PEAK_MEM_RAW=0
    fi
    PEAK_MEM_RAW=$(echo "$PEAK_MEM_RAW/1024/1024" | bc -l)

    docker rm -f "$CID" > /dev/null 2>&1

    # --------------------------------------------------------
    # Affichage Markdown pour Quarto
    # --------------------------------------------------------
    printf "| %-15s | %10s | %10s | %11s | %8s | %8.2f MB |\n" \
        "$TAG" "$COLD_TIME" "$WARM_TIME" "$INCR_TIME" \
        "$SIZE_STR" "$PEAK_MEM_RAW"
done

echo -e "\n*Note : Footprint Index = (RAM × 3) + (Size / 10). Plus l'indice est faible, plus l'image est efficiente.*"