Makefile Automating daily tasks & simplifying getting started Gustavo Pantuza 

@gpantuza @pantuza https://blog.pantuza.com 

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Agenda Introduction Properties Advanced ● Motivation ● How it works ● File Format ● Demo ● Variables ● Conditionals ● Builtin functions ● Includes ● Defining Functions ● Automatic Variables ● Caveats ● Other directory ● Use cases 

Introduction 

● Automation ● Simplicity ● Learning curve ● Getting Started ● Almost no dependencies Motivation 

● Program make zypper install make apk add make apt-get install make ● A Makefile The file which make reads in order to execute rules How it work $> make build 

By the original definition make is: “The make utility automatically determines which pieces of a large program need to be recompiled, and issues commands to recompile them.” How it work $> make what Overview 

$> make build Building docker image Sending build context to Docker daemon 73.73kB Step 1/4 : FROM golang:1.14-alpine ---> 30df784d6206 Step 2/4 : COPY src /app ---> 5fa423e5e748 Step 3/4 : WORKDIR /app ---> Running in 3a969fe98be8 Removing intermediate container 3a969fe98be8 ---> 3a59a136b09c Step 4/4 : CMD go run main.go ---> Running in 49907a2f877a Removing intermediate container 49907a2f877a ---> 14ec4f19142c Successfully built 14ec4f19142c Successfully tagged makefile:latest How it work $> make build Overview 

make rules File format Rule Shape 

target: dependency command File format Rule Shape 

● target Action to be executed by the rule ● dependencies Needed to exist to satisfy the target ● commands Sequence of commands to be executed File format 

target..: dependency.. command.. .. File format Rule Shape 

target..: dependency.. command.. .. File format Rule Shape 

Hands On 

Properties 

# Branch that triggers production deployment PROD_BRANCH := production # Push current branch changes to production branch push: $(info Pushing changes to $(PROD_BRANCH)) @git push origin $(PROD_BRANCH) Variables $> make push Pushing changes to production Everything up-to-date 

# Docker image version IMG_VERSION ?= latest # Builds the docker image based on the Dockerfile build: Dockerfile $(info Building docker image) @docker build --tag makefile:$(IMG_VERSION) . Variables $> make build ... Successfully tagged makefile:latest $> make build IMG_VERSION=0.2 ... Successfully tagged makefile:0.2 $> make build IMG_VERSION=beta ... Successfully tagged makefile:beta 

# Source code directory SRC := src GO_FILES := $(SRC)/main.go $(SRC)/main_test.go # Runs code format on Golang files fmt: $(GO_FILES) $(info Running Go fmt on $(GO_FILES)) @go fmt $^ Variables $> make fmt Running Go fmt on src/main.go src/main_test.go 

# Expanded once VERSION := 0.12 # Expanded on call NOW = $(shell date +%s) # Conditional assignment IMG_TAG ?= latest # Appending values CFLAGS += -O3 Variables 

# Rolls back application to specific version rollback: ifndef ROLLBACK_VERSION $(error Missing ROLLBACK_VERSION variable) endif @kubectl rollout undo deployment app --to-revision=$(ROLLBACK_VERSION) Conditionals $> make rollback Makefile:36: *** Missing ROLLBACK_VERSION variable. Stop. $> make rollback ROLLBACK_VERSION=15 ... 

# Operating system name OS := $(shell uname) # Install project dependencies on the Operating System deps: $(info Installing project dependencies locally) ifeq ($(OS),Linux) @zypper install --no-confirm nginx else ifeq ($(OS), Darwin) @brew install nginx else $(warning Unsupported Operating System) endif Conditionals $> make deps # Else example Makefile:36: Unsupported Operating System $> make deps # Linux example Installing project dependencies locally ... Conditionals 

# List of files to be modified FILES := src/a src/b bin/a bin/b # String functions examples functions: @echo "Input: $(FILES)" @echo "subst -> " $(subst src, tmp, $(FILES)) @echo "filter -> " $(filter bin%, $(FILES)) @echo "findstring -> " $(findstring a, $(FILES)) @echo "sort -> " $(sort $(FILES)) @echo "word -> " $(word 2, $(FILES)) @echo "lastword -> " $(lastword, $(FILES)) Builtin functions $> make functions Input: src/a src/b bin/a bin/b subst -> tmp/a tmp/b bin/a bin/b filter -> bin/a bin/b findstring -> a sort -> bin/a bin/b src/a src/b word -> src/b lastword -> bin/b Text Functions 

# List of files to be modified FILES := src/a src/b bin/a bin/b # Files functions examples functions: @echo "Input: $(FILES)" @echo "dir -> " $(dir $(FILES)) @echo "notdir -> " $(notdir $(FILES)) @echo "basename -> " $(basename $(FILES)) @echo "addsuffix -> " $(addsuffix .go, $(FILES)) @echo "addprefix -> " $(addprefix /tmp/, $(FILES)) @echo "abspath -> " $(abspath $(FILES)) Builtin functions $> make functions Input: src/a src/b bin/a bin/b dir -> src/ src/ bin/ bin/ notdir -> a b a b basename -> src/a src/b bin/a bin/b addsuffix -> src/a.go src/b.go bin/a.go bin/b.go addprefix -> /tmp/src/a /tmp/src/b /tmp/bin/a /tmp/bin/b abspath -> /makefile/src/a /makefile/src/b /makefile/bin/a /makefile/bin/b Files Functions 

# List of directories DIRS := src bin logs # Directories with suffix SUF_DIRS := $(foreach dir, $(DIRS), $(addsuffix -dir, $(dir))) # Runtime functions examples runtime: @echo "$(shell hostname)" @echo $(SUF_DIRS) @echo $(wildcard src/*_test.go) $(eval AWS_ACCOUNT = $(shell aws sts get-caller-identity --query "Account")) @echo $(AWS_ACCOUNT) Builtin functions $> make runtime opensuse-machine src-dir bin-dir logs-dir src/main_test.go 151666326780 

# Builtin functions to print messages messages: $(info Informative function) $(warning Warning function) $(error Error function) Builtin functions $> make messages Informative function Makefile:40: Warning function Makefile:41: *** Error function. Stop. Text Functions 

# Includes an external Makefile include Makefile.conf # Gets project version read # included Makefile.conf version: @echo $(VERSION) @echo $(PROJECT_NAME) @echo $(DOCS) @echo $(PKG_MGR) Includes $> make version 0.42 makefile docs /usr/bin/zypper # =====* Makefile.conf *===== # Shell program SHELL := $(shell which bash) # Gets from shell the operating system OS := $(shell uname -s) PKG_MGR := $(shell which zypper) ifeq ($(OS), Darwin) PKG_MGR = $(shell which brew) endif # Project name PROJECT_NAME := makefile # Get the version from file VERSION := 0.42 # Documentation directory DOCS := docs 

Advanced 

# # Returns current timestamp (no parameters) # NOW = $(shell date +%s) # # Function to subtract the first number from the second # (with parameters) SUBTRACT = $(shell expr $(1) - $(2) ) time: @echo "Now: $(call NOW)" @echo "Subtract 20 from 30: $(call SUBTRACT, 30, 20)" Functions $> make time Now: 1595898056 Subtract 20 from 30: 10 

# # Function that takes a template and a variable as input. # It returns template text interpolated with the variable. # define parse_template @echo $(1) | sed 's/{NAME}/$(2)/' endef # Builds templates dynamically template: $(call parse_template,"Learning {NAME} rocks!",Makefile) $(call parse_template,"Learning {NAME} rocks!",Computer Science) $(call parse_template,"Learning {NAME} rocks!",DevOps) Functions $> make template Learning Makefile rocks! Learning Computer Science rocks! Learning DevOps rocks! 

# Magic variables example magic: Dockerfile README.md LICENSE @echo $< @echo $^ @echo $@ Automatic variables $> make magic Dockerfile Dockerfile README.md LICENSE magic Automatic Variables 

# Resolve git command path GIT := $(shell which git) push: @$(GIT) push origin master Caveats $> make push Enumerating objects: 5, done. Counting objects: 100% (5/5), done. Delta compression using up to 8 threads Compressing objects: 100% (3/3), done. Writing objects: 100% (3/3), 1014 bytes | 1014.00 KiB/s, done. Total 3 (delta 2), reused 0 (delta 0) remote: Resolving deltas: 100% (2/2), completed with 2 local objects. To github.com:pantuza/makefile.git d865102..493d7cd master -> master 

# @ before command avoid printing the command hide: @echo "No command shown, only result" show: echo "Command shown and also the result" Caveats $> make hide No command shown, only result $> make show echo "Command shown and also the result" Command shown and also the result 

# .PHONY make sure to not fail if the target is # equal to a file or directory .PHONY: src src: @echo "Hi PHONY target" Caveats $> ls Dockerfile LICENSE Makefile README.md src $> make src # Whitout .PHONY make: 'src' is up to date. $> make src # Using .PHONY Hi PHONY target 

# Using Wildcards # Validates all OpenAPI spec files check_spec: $(SRC)/%.yaml @openapi-spec-validator $^ Caveats $> make check_spec OK 

Caveats # Chaining rules $> make start logs Running application container 6de3d88c680d57da5658a5007b988cdaed909e8cb588af20b1bc9100ca2bad07 [Http] Status=Listening, Port=8080 

Caveats # Debugging with -n option $> make build start logs -n Building docker image docker build --tag makefile:latest . Running application container docker run -it --rm -p 8080:8080 --name makefile -d makefile:latest docker logs --tail 50 --follow makefile 

# Makefile on an inner directory # For example /lib/Makefile binary: main.go @go build -o $@ Other directories $> make -C lib/ binary make: Entering directory '/makefile/lib' make: Leaving directory '/makefile/lib' 

Use cases # Jenkinsfile ... stage('Unit Tests') { steps { echo 'Running Unit Tests..' sh 'make unit_test' } } stage('Integration Tests') { steps { echo 'Running Integration Tests..' sh 'make integration_test' } } ... 

Use cases # .travis.yml sudo: required language: cpp services: - docker before_install: - make start script: - make test 

Use cases # DRY - Don’t Repeat Yourself # CI/CD Pipeline execution chain pipeline: pep8 check_openapi check_k8s unit_test integration_test acceptance_test # Deploy application to production deploy: cloud_auth build_img push_img migrate_db patch @kubectl rollout status deployment $(DEPLOYMENT_NAME) @kubectl apply -f $(K8S_DIR)/deployment.yaml 

Use cases # Getting started In order to have the project running locally you can just run as follows: ```bash $> make setup ``` > It will install all project dependencies and > and run application using containers You can check if everything is OK by running the tests: ```bash $> make test ``` If everything went well, please refer to the CONTRIBUTING.md and start contributing to the Project! 

Use cases Kubernetes Python language NodeJS BusyBox Docker CLI Prometheus Traefik Terraform 

Automating & simplifying 

https://github.com/pantuza/makefile https://www.gnu.org/software/make/manual/make.html 

Desconto de 50% na compra de SSL Utilize o código DEVBR50OFF 

https://blog.pantuza.com https://github.com/pantuza https://twitter.com/gpantuza Dúvidas?