docker-php-extensions-knowledge
Docker PHP extensions knowledge base. Provides installation patterns for common extensions, build dependency management, and PECL usage.
Best use case
docker-php-extensions-knowledge is best used when you need a repeatable AI agent workflow instead of a one-off prompt.
Docker PHP extensions knowledge base. Provides installation patterns for common extensions, build dependency management, and PECL usage.
Teams using docker-php-extensions-knowledge should expect a more consistent output, faster repeated execution, less prompt rewriting.
When to use this skill
- You want a reusable workflow that can be run more than once with consistent structure.
When not to use this skill
- You only need a quick one-off answer and do not need a reusable workflow.
- You cannot install or maintain the underlying files, dependencies, or repository context.
Installation
Claude Code / Cursor / Codex
Manual Installation
- Download SKILL.md from GitHub
- Place it in
.claude/skills/docker-php-extensions-knowledge/SKILL.mdinside your project - Restart your AI agent — it will auto-discover the skill
How docker-php-extensions-knowledge Compares
| Feature / Agent | docker-php-extensions-knowledge | Standard Approach |
|---|---|---|
| Platform Support | Not specified | Limited / Varies |
| Context Awareness | High | Baseline |
| Installation Complexity | Unknown | N/A |
Frequently Asked Questions
What does this skill do?
Docker PHP extensions knowledge base. Provides installation patterns for common extensions, build dependency management, and PECL usage.
Where can I find the source code?
You can find the source code on GitHub using the link provided at the top of the page.
SKILL.md Source
# Docker PHP Extensions Knowledge Base
Patterns for installing, building, and managing PHP extensions in Docker containers.
## Extension Categories
| Category | Extensions | Purpose |
|----------|-----------|---------|
| **Core** | opcache, intl, mbstring, bcmath | Performance, i18n, math |
| **Database** | pdo_pgsql, pdo_mysql, pgsql, mysqli | Database connectivity |
| **Cache** | redis, apcu, memcached | Caching layers |
| **Crypto** | sodium, openssl | Encryption, hashing |
| **Image** | gd, imagick | Image processing |
| **Archive** | zip, zlib, bz2 | Compression |
| **Message** | amqp, pcntl | Queues, process control |
| **Debug** | xdebug, pcov | Debugging, coverage |
| **Serialization** | igbinary, msgpack | Fast serialization |
## Installation Methods
### Method 1: docker-php-ext-install (Built-in Extensions)
```dockerfile
# Extensions bundled with PHP source
RUN docker-php-ext-install -j$(nproc) \
opcache \
intl \
pdo_pgsql \
pdo_mysql \
zip \
bcmath \
pcntl \
sockets
```
### Method 2: docker-php-ext-configure + install
```dockerfile
# Extensions requiring configuration
RUN docker-php-ext-configure gd \
--with-freetype \
--with-jpeg \
--with-webp \
&& docker-php-ext-install -j$(nproc) gd
```
### Method 3: PECL Install
```dockerfile
# Extensions from PECL repository
RUN pecl install redis-6.1.0 apcu-5.1.24 igbinary-3.2.16 \
&& docker-php-ext-enable redis apcu igbinary
```
### Method 4: Manual Compilation
```dockerfile
# For extensions not in PECL or needing custom patches
RUN curl -fsSL https://github.com/example/ext/archive/v1.0.tar.gz | tar xz \
&& cd ext-1.0 \
&& phpize \
&& ./configure \
&& make -j$(nproc) \
&& make install \
&& docker-php-ext-enable ext
```
## Alpine vs Debian Build Dependencies
| Extension | Alpine Packages | Debian Packages |
|-----------|----------------|-----------------|
| intl | `icu-dev` | `libicu-dev` |
| pdo_pgsql | `libpq-dev` | `libpq-dev` |
| pdo_mysql | (none) | (none) |
| gd | `freetype-dev libjpeg-turbo-dev libpng-dev libwebp-dev` | `libfreetype6-dev libjpeg62-turbo-dev libpng-dev libwebp-dev` |
| zip | `libzip-dev` | `libzip-dev` |
| imagick | `imagemagick-dev` | `libmagickwand-dev` |
| amqp | `rabbitmq-c-dev` | `librabbitmq-dev` |
| memcached | `libmemcached-dev zlib-dev` | `libmemcached-dev zlib1g-dev` |
| sodium | `libsodium-dev` | `libsodium-dev` |
| bz2 | `bzip2-dev` | `libbz2-dev` |
| xsl | `libxslt-dev` | `libxslt1-dev` |
| ldap | `openldap-dev` | `libldap2-dev` |
| gmp | `gmp-dev` | `libgmp-dev` |
| imap | `imap-dev krb5-dev` | `libc-client-dev libkrb5-dev` |
## Runtime vs Build Dependencies Pattern
```dockerfile
FROM php:8.4-fpm-alpine AS production
# 1. Install build dependencies (virtual package for easy removal)
RUN apk add --no-cache --virtual .build-deps \
$PHPIZE_DEPS \
icu-dev \
libpq-dev \
libzip-dev \
freetype-dev \
libjpeg-turbo-dev \
libpng-dev \
rabbitmq-c-dev \
\
# 2. Install and configure extensions
&& docker-php-ext-configure gd --with-freetype --with-jpeg \
&& docker-php-ext-install -j$(nproc) \
intl \
pdo_pgsql \
zip \
gd \
opcache \
bcmath \
pcntl \
sockets \
\
# 3. Install PECL extensions
&& pecl install redis apcu amqp igbinary \
&& docker-php-ext-enable redis apcu amqp igbinary \
\
# 4. Remove build dependencies (keep runtime libs)
&& apk del .build-deps
# 5. Install runtime-only libraries
RUN apk add --no-cache \
icu-libs \
libpq \
libzip \
freetype \
libjpeg-turbo \
libpng \
rabbitmq-c
```
## Extension Builder Stage Pattern
```dockerfile
# Dedicated stage for compiling extensions (reusable across images)
FROM php:8.4-fpm-alpine AS ext-builder
RUN apk add --no-cache --virtual .build-deps \
$PHPIZE_DEPS \
icu-dev \
libpq-dev \
libzip-dev \
&& docker-php-ext-install -j$(nproc) intl pdo_pgsql zip opcache bcmath \
&& pecl install redis apcu \
&& docker-php-ext-enable redis apcu \
&& apk del .build-deps
# Production stage copies only compiled artifacts
FROM php:8.4-fpm-alpine AS production
COPY --from=ext-builder /usr/local/lib/php/extensions/ /usr/local/lib/php/extensions/
COPY --from=ext-builder /usr/local/etc/php/conf.d/ /usr/local/etc/php/conf.d/
RUN apk add --no-cache icu-libs libpq libzip
```
## Framework Extension Combinations
### Symfony Stack
```dockerfile
RUN docker-php-ext-install -j$(nproc) \
intl \ # Translation, validation, routing
pdo_pgsql \ # Doctrine DBAL (PostgreSQL)
opcache \ # Performance
zip \ # Composer, file handling
bcmath \ # Precise math (money)
pcntl \ # Messenger async workers
sockets # Messenger AMQP transport
RUN pecl install redis apcu amqp \
&& docker-php-ext-enable redis apcu amqp
```
### Laravel Stack
```dockerfile
RUN docker-php-ext-install -j$(nproc) \
pdo_mysql \ # Eloquent (MySQL)
opcache \ # Performance
zip \ # File handling
bcmath \ # Precise math
pcntl \ # Horizon workers
exif # Image metadata
RUN pecl install redis igbinary \
&& docker-php-ext-enable redis igbinary
```
### API Platform / High-Load
```dockerfile
RUN docker-php-ext-install -j$(nproc) \
intl \
pdo_pgsql \
opcache \
bcmath \
pcntl \
sockets
RUN pecl install redis apcu amqp igbinary msgpack \
&& docker-php-ext-enable redis apcu amqp igbinary msgpack
```
## OPcache Configuration for Production
```ini
; /usr/local/etc/php/conf.d/opcache.ini
opcache.enable=1
opcache.enable_cli=0
opcache.memory_consumption=256
opcache.interned_strings_buffer=32
opcache.max_accelerated_files=20000
opcache.validate_timestamps=0
opcache.save_comments=1
opcache.jit=tracing
opcache.jit_buffer_size=128M
```
```dockerfile
COPY docker/php/opcache.ini /usr/local/etc/php/conf.d/opcache.ini
```
## Troubleshooting
| Issue | Cause | Solution |
|-------|-------|----------|
| `cannot find -licu` | Missing icu-dev | `apk add icu-dev` or `apt install libicu-dev` |
| `pecl install fails` | Missing $PHPIZE_DEPS | `apk add $PHPIZE_DEPS` |
| Extension loads but segfaults | Alpine musl incompatibility | Switch to Debian base |
| `Class 'Redis' not found` | Extension not enabled | `docker-php-ext-enable redis` |
| `iconv(): Wrong encoding` | Alpine musl iconv | Install `gnu-libiconv` |
| Slow builds | Sequential compilation | Use `-j$(nproc)` and BuildKit cache |
## References
For the full extensions matrix with all dependencies, see `references/extensions-matrix.md`.
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