adding help to makefile

this makes the makefile a little easier to grok: now 'make' or 'make help' will list make targets and a brief description of what they do

Makefile

@@ -1,38 +1,45 @@
 PHP_VERSION ?= 7.4
 DC_RUN_PHP = docker-compose run --rm php
 
-all: update rector style deptrac packages-composer  phan psalm phpstan test
-install:
+.DEFAULT_GOAL : help
+
+help: ## Show this help
+	@printf "\033[33m%s:\033[0m\n" 'Available commands'
+	@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z0-9_-]+:.*?## / {printf "  \033[32m%-18s\033[0m %s\n", $$1, $$2}' $(MAKEFILE_LIST)
+all: update rector style deptrac packages-composer phan psalm phpstan test ## Run all tests, linting, checks
+pull: ## Pull latest developer image
+	docker-compose pull php
+install: ## Install dependencies
 	$(DC_RUN_PHP) env XDEBUG_MODE=off composer install
-update:
+update: ## Update dependencies
 	$(DC_RUN_PHP) env XDEBUG_MODE=off composer update
-test: test-unit test-integration
-test-unit:
+test: test-unit test-integration ## Run unit and integration tests
+test-unit: ## Run unit tests
 	$(DC_RUN_PHP) env XDEBUG_MODE=coverage vendor/bin/phpunit --testsuite unit --colors=always --coverage-text --testdox --coverage-clover coverage.clover --coverage-html=tests/coverage/html --log-junit=junit.xml
-test-integration:
+test-integration: ## Run integration tests
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/phpunit --testsuite integration --colors=always
-test-coverage:
+test-coverage: ## Run units tests and generate code coverage
 	$(DC_RUN_PHP) env XDEBUG_MODE=coverage vendor/bin/phpunit --testsuite unit --coverage-html=tests/coverage/html
-test-compliance:
+test-compliance: ## Run compliance tests
 	$(DC_RUN_PHP) env XDEBUG_MODE=coverage vendor/bin/phpunit --group compliance
-test-trace-compliance:
+test-trace-compliance: ## Run trace compliance tests
 	$(DC_RUN_PHP) env XDEBUG_MODE=coverage vendor/bin/phpunit --group trace-compliance
-phan:
+phan: ## Run phan
 	$(DC_RUN_PHP) env XDEBUG_MODE=off env PHAN_DISABLE_XDEBUG_WARN=1 vendor/bin/phan
-psalm:
+psalm: ## Run psalm
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/psalm --threads=1 --no-cache
-psalm-info:
+psalm-info: ## Run psalm and show info
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/psalm --show-info=true --threads=1
-phpstan:
+phpstan: ## Run phpstan
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/phpstan analyse --memory-limit=256M
-packages-composer:
+packages-composer: ## Validate composer packages
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/otel packages:composer:validate
-benchmark:
+benchmark: ## Run phpbench
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/phpbench run --report=default
-phpmetrics:
+phpmetrics: ## Run php metrics
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/phpmetrics --config=./phpmetrics.json --junit=junit.xml
-smoke-test-examples: smoke-test-isolated-examples smoke-test-exporter-examples smoke-test-collector-integration smoke-test-prometheus-example
-smoke-test-isolated-examples:
+smoke-test-examples: smoke-test-isolated-examples smoke-test-exporter-examples smoke-test-collector-integration smoke-test-prometheus-example ## Run smoke test examples
+smoke-test-isolated-examples: ## Run smoke test isolated examples
 	$(DC_RUN_PHP) php ./examples/traces/getting_started.php
 	$(DC_RUN_PHP) php ./examples/traces/features/always_off_trace_example.php
 	$(DC_RUN_PHP) php ./examples/traces/features/batch_exporting.php
@@ -45,7 +52,7 @@ smoke-test-isolated-examples:
 	$(DC_RUN_PHP) php ./examples/traces/troubleshooting/air_gapped_trace_debugging.php
 	$(DC_RUN_PHP) php ./examples/traces/troubleshooting/logging_of_span_data.php
 	$(DC_RUN_PHP) php ./examples/traces/troubleshooting/setting_up_logging.php
-smoke-test-exporter-examples: FORCE
+smoke-test-exporter-examples: FORCE ## Run (some) exporter smoke test examples
 # Note this does not include every exporter at the moment
 	docker-compose up -d --remove-orphans
 	$(DC_RUN_PHP) php ./examples/traces/features/exporters/zipkin.php
@@ -55,7 +62,7 @@ smoke-test-exporter-examples: FORCE
 	docker-compose run -e NEW_RELIC_ENDPOINT -e NEW_RELIC_INSERT_KEY --rm php php ./examples/traces/features/exporters/newrelic.php
 	docker-compose run -e NEW_RELIC_ENDPOINT -e NEW_RELIC_INSERT_KEY --rm php php ./examples/traces/features/exporters/zipkin_to_newrelic.php
 	docker-compose stop
-smoke-test-collector-integration:
+smoke-test-collector-integration: ## Run smoke test collector integration
 	docker-compose -f docker-compose.collector.yaml up -d --remove-orphans
 # This is slow because it's building the image from scratch (and parts of that, like installing the gRPC extension, are slow)
 # This can be sped up by switching to the pre-built images hosted on ghcr.io (and referenced in other docker-compose**.yaml files) 
@@ -70,24 +77,24 @@ stop-prometheus:
 	@docker-compose -f docker-compose.prometheus.yaml -p opentelemetry-php_metrics-prometheus-example stop
 fiber-ffi-example:
 	@docker-compose -f docker-compose.fiber-ffi.yaml -p opentelemetry-php_fiber-ffi-example up -d web
-protobuf:
+protobuf: ## Generate protobuf files
 	./script/proto_gen.sh
-thrift:
+thrift: ## Generate thrift files
 	./script/thrift_gen.sh
-bash:
+bash: ## bash shell into container
 	$(DC_RUN_PHP) bash
-style:
+style: ## Run style check/fix
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/php-cs-fixer fix --config=.php-cs-fixer.php --using-cache=no -vvv
-rector:
+rector: ## Run rector
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/rector process src
-rector-dry:
+rector-dry: ## Run rector (dry-run)
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/rector process src --dry-run
-deptrac:
+deptrac: ## Run deptrac
 	$(DC_RUN_PHP) env XDEBUG_MODE=off vendor/bin/deptrac --formatter=table --report-uncovered --no-cache
 w3c-test-service:
 	@docker-compose -f docker-compose.w3cTraceContext.yaml run --rm php ./tests/TraceContext/W3CTestService/trace-context-test.sh
-semconv:
+semconv: ## Generate semconv files
 	./script/semantic-conventions/semconv.sh
-split:
+split: ## Run git split
 	docker-compose -f docker/gitsplit/docker-compose.yaml --env-file ./.env up
 FORCE: