PHPアプリケーションのコンテナ化

PHPをコンテナ化する理由

FPMとApacheのベースイメージ

# Base image choice in your Dockerfile
FROM php:8.3-fpm-alpine AS base

# Why alpine? ~30MB base vs ~140MB Debian.
# Tradeoff: musl libc, occasional native-extension friction.

拡張機能をインストールする

FROM php:8.3-fpm-alpine

# Grab the helper that resolves build deps automatically
ADD https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions /usr/local/bin/

RUN chmod +x /usr/local/bin/install-php-extensions && \
    install-php-extensions \
        pdo_mysql \
        opcache \
        intl \
        zip \
        redis \
        bcmath

イメージ内のComposer

COPY --from=composer:2 /usr/bin/composer /usr/bin/composer

WORKDIR /app

# Cache-friendly: deps layer invalidates only when lock changes
COPY composer.json composer.lock ./
RUN composer install \
        --no-dev \
        --no-scripts \
        --no-autoloader \
        --prefer-dist

COPY . .
RUN composer dump-autoload --optimize --classmap-authoritative

php.iniを調整する

# Activate production ini
RUN mv "$PHP_INI_DIR/php.ini-production" "$PHP_INI_DIR/php.ini"

# Custom overrides win because conf.d loads last
COPY docker/php/zz-app.ini $PHP_INI_DIR/conf.d/zz-app.ini

OPcacheの上書きファイル

; docker/php/zz-app.ini
memory_limit = 256M
expose_php = Off

opcache.enable = 1
opcache.enable_cli = 0
opcache.memory_consumption = 256
opcache.interned_strings_buffer = 16
opcache.max_accelerated_files = 20000
opcache.validate_timestamps = 0
opcache.preload = /app/preload.php
opcache.preload_user = www-data

非rootで実行する

# Make runtime-writable dirs owned by the runtime user
RUN chown -R www-data:www-data /app/var /app/storage 2>/dev/null || true

USER www-data

EXPOSE 9000
CMD ["php-fpm"]

ヘルスチェック

# In www.conf pool config:
;   ping.path = /ping
;   ping.response = pong

# Dockerfile HEALTHCHECK using cgi-fcgi
RUN install-php-extensions @composer >/dev/null 2>&1 || true

HEALTHCHECK --interval=10s --timeout=3s --retries=3 \
  CMD SCRIPT_NAME=/ping SCRIPT_FILENAME=/ping REQUEST_METHOD=GET \
      cgi-fcgi -bind -connect 127.0.0.1:9000 || exit 1

Dockerfileを組み立てる

FROM php:8.3-fpm-alpine

ADD https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions /usr/local/bin/
RUN chmod +x /usr/local/bin/install-php-extensions && \
    install-php-extensions pdo_mysql opcache intl zip redis

COPY --from=composer:2 /usr/bin/composer /usr/bin/composer
WORKDIR /app

RUN mv "$PHP_INI_DIR/php.ini-production" "$PHP_INI_DIR/php.ini"
COPY docker/php/zz-app.ini $PHP_INI_DIR/conf.d/

COPY composer.json composer.lock ./
RUN composer install --no-dev --no-scripts --no-autoloader --prefer-dist
COPY . .
RUN composer dump-autoload --optimize --classmap-authoritative && \
    chown -R www-data:www-data /app/var

USER www-data
EXPOSE 9000
CMD ["php-fpm"]

ビルドを検証する

<?php
// Run inside the container: php verify.php
echo 'PHP ' . PHP_VERSION . PHP_EOL;

$required = ['pdo_mysql', 'opcache', 'intl', 'zip'];
foreach ($required as $ext) {
    printf("%-12s %s\n", $ext, extension_loaded($ext) ? 'OK' : 'MISSING');
}

var_dump((bool) ini_get('opcache.enable'));
?>

ビルドコンテキストを整理する

# .dockerignore
.git
.gitignore
vendor/
node_modules/
.env
.env.*
tests/
*.md
docker-compose*.yml
storage/logs/*
var/cache/*

確認

まとめ