PHP auto - build binaries with Docker instead of Shell

[BenElferink]

          How about running this inside the Dockerfile? As part of a multi-stage build

Originally posted by @iblancasa in #3409 (comment)

---

I noticed the discussion referenced above, and have already done this for Odigos auto-instrumentation. So I thought I could start this issue to discuss on implementing this for OpenTelemetry.

Here's the repo for full inspection (some of it is still a work in progress, focus on v8.1): https://github.com/odigos-io/opentelemetry-php

Dockerfile for building the binaries (per PHP version):

ARG PHP_VERSION
FROM --platform=$BUILDPLATFORM php:${PHP_VERSION}-cli AS builder
ARG PHP_VERSION
ARG PHP_OTEL_VERSION
WORKDIR /${PHP_VERSION}

# Install system/docker dependencies
RUN apt-get update && apt-get upgrade -y \
  && apt-get install -y wget unzip gcc make autoconf libicu-dev \
  && curl -sS https://getcomposer.org/installer | php && mv composer.phar /usr/local/bin/composer

# Install the OTel extension (see https://opentelemetry.io/docs/zero-code/php/#install-the-opentelemetry-extension)
RUN pecl install opentelemetry-${PHP_OTEL_VERSION} \
  && docker-php-ext-enable opentelemetry

# Isolate the binary & create a pointer
RUN cp "$(php-config --extension-dir)/opentelemetry.so" opentelemetry.so
RUN echo "extension=/var/odigos/php/${PHP_VERSION}/opentelemetry.so\nauto_prepend_file=/var/odigos/php/${PHP_VERSION}/index.php" > opentelemetry.ini

# Enable extensions (for 'composer install' below)
RUN cp opentelemetry.so "$(php-config --extension-dir)/opentelemetry.so" \
  && docker-php-ext-enable opentelemetry
# Install composer libraries
COPY ./${PHP_VERSION}/composer.json .
RUN composer install --no-dev --optimize-autoloader --ignore-platform-reqs

FROM scratch AS output
ARG PHP_VERSION
COPY --from=builder ./${PHP_VERSION} ./${PHP_VERSION}
CMD ["ls", "-al", "./${PHP_VERSION}"]

Makefile for building the images, mounting the containers, extracting the binaries, and then unmounting the containers:

PHP_OTEL_VERSION=1.1.2
PHP_VERSIONS=8.0 8.1 8.2 8.3 8.4
DOCKER_MOUNT_NAME=php-otel-ext-out

# Helper method to switch PHP version during development
.PHONY: switch-php/%
switch-php/%:
	@for v in $(PHP_VERSIONS); do \
		brew unlink php@$$v || true; \
	done
	@if [ "$*" = "8.0" ]; then \
		brew install shivammathur/php/[email protected]; \
	else \
		brew install php@$* || true; \
	fi
	@brew link --overwrite --force php@$*

# Main method to build the binaries
.PHONY: all
all:
	@$(MAKE) -j $(nproc) binaries

delete-files/%:
	@rm -rf ./$*/vendor
	@rm -rf ./$*/composer.lock
	@rm -rf ./$*/opentelemetry.so
	@rm -rf ./$*/opentelemetry.ini

copy-files-from-container/%:
	@docker cp ${DOCKER_MOUNT_NAME}-$*:/$*/vendor ./$*/vendor
	@docker cp ${DOCKER_MOUNT_NAME}-$*:/$*/composer.lock ./$*/composer.lock
	@docker cp ${DOCKER_MOUNT_NAME}-$*:/$*/opentelemetry.so ./$*/opentelemetry.so
	@docker cp ${DOCKER_MOUNT_NAME}-$*:/$*/opentelemetry.ini ./$*/opentelemetry.ini

build-image/%:
	@docker build --target output -t ${DOCKER_MOUNT_NAME}:$* -f Dockerfile \
		--build-arg PHP_OTEL_VERSION=$(PHP_OTEL_VERSION) \
		--build-arg PHP_VERSION=$* .

mount-container/%:
	@docker create --name ${DOCKER_MOUNT_NAME}-$* ${DOCKER_MOUNT_NAME}:$*

unmount-container/%:
	@docker rm ${DOCKER_MOUNT_NAME}-$*

.PHONY: binaries
binaries:
	@for v in $(PHP_VERSIONS); do \
		$(MAKE) delete-files/$$v; \
		$(MAKE) build-image/$$v; \
		$(MAKE) mount-container/$$v; \
		$(MAKE) copy-files-from-container/$$v; \
		$(MAKE) unmount-container/$$v; \
	done

[BenElferink]

P.S.

The Makefile can be made easier by using docker bake for matrix-like execution, the Dockerfile does not need any changes, just a relevant docker-bake.hcl or docker-bake.json.

Execute with:

docker buildx bake --file docker-bake.json --set *.args.PHP_OTEL_VERSION=1.1.2

Example .json:

{
  "group": {
    "default": {
      "targets": ["php80", "php81", "php82", "php83", "php84"]
    }
  },
  "variable": {
    "PHP_OTEL_VERSION": {
      "default": "1.1.2"
    }
  },
  "target": {
    "php-base": {
      "context": ".",
      "dockerfile": "Dockerfile",
      "target": "output",
      "args": {
        "PHP_OTEL_VERSION": "${PHP_OTEL_VERSION}"
      }
    },
    "php80": {
      "inherits": ["php-base"],
      "tags": ["php-otel-ext-out:8.0"],
      "args": {
        "PHP_VERSION": "8.0"
      }
    },
    "php81": {
      "inherits": ["php-base"],
      "tags": ["php-otel-ext-out:8.1"],
      "args": {
        "PHP_VERSION": "8.1"
      }
    },
    "php82": {
      "inherits": ["php-base"],
      "tags": ["php-otel-ext-out:8.2"],
      "args": {
        "PHP_VERSION": "8.2"
      }
    },
    "php83": {
      "inherits": ["php-base"],
      "tags": ["php-otel-ext-out:8.3"],
      "args": {
        "PHP_VERSION": "8.3"
      }
    },
    "php84": {
      "inherits": ["php-base"],
      "tags": ["php-otel-ext-out:8.4"],
      "args": {
        "PHP_VERSION": "8.4"
      }
    }
  }
}