Merge pull request #5 from petzich/develop

Switch main image to Alpine

Dockerfile.alpine

@@ -0,0 +1 @@
+Dockerfile.alpine.3.9

Dockerfile.alpine.3.9

@@ -0,0 +1,8 @@
+FROM alpine:3.9
+ENTRYPOINT ["pre-commit", "run", "--config", "/.pre-commit-config.yaml"]
+RUN apk add --no-cache \
+    git \
+    python3
+COPY requirements.txt .
+RUN pip3 install --no-cache-dir -r requirements.txt
+RUN pre-commit sample-config > /.pre-commit-config.yaml

Makefile

@@ -0,0 +1,47 @@
+# Makefile for petzi/docker-pre-commit
+# Make targets to help in the development of this docker image
+
+.DEFAULT_GOAL := help
+
+# Docker configuration
+DOCKER=docker
+# Docker build configuration
+DOCKER_TAG=petzi/pre-commit
+DOCKER_TAG_ALPINE=$(DOCKER_TAG):alpine
+DOCKER_TAG_UBUNTU=$(DOCKER_TAG):ubuntu
+
+# Docker run configuration for the main image
+DOCKER_VOL=-v "${PWD}:/src"
+DOCKER_WD=-w "/src"
+DOCKER_RUN=$(DOCKER) run --rm $(DOCKER_VOL) $(DOCKER_WD)
+
+# Configuration for wagoodman/dive
+DIVE_IMAGE=wagoodman/dive
+DIVE_VERSION=v0.7.2
+DIVE=$(DIVE_IMAGE):$(DIVE_VERSION)
+DIVE_VOL=-v "/var/run/docker.sock:/var/run/docker.sock"
+DIVE_CI=-e CI=true
+DIVE_RUN=$(DOCKER) run --rm $(DIVE_CI) $(DIVE_VOL) $(DIVE)
+
+# The help command is inspired by this post:
+# https://marmelab.com/blog/2016/02/29/auto-documented-makefile.html
+.PHONY: help
+help:
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
+
+.PHONY: build
+build:  ## Build the images on development
+	$(DOCKER) build -t $(DOCKER_TAG) .
+	$(DOCKER) build -f Dockerfile.alpine -t $(DOCKER_TAG_ALPINE) .
+	$(DOCKER) build -f Dockerfile.ubuntu -t $(DOCKER_TAG_UBUNTU) .
+
+.PHONY: ci-image-size
+ci-image-size: ## Run docker image size analysis
+	$(DIVE_RUN) $(DOCKER_TAG_ALPINE)
+	$(DIVE_RUN) $(DOCKER_TAG_UBUNTU)
+
+.PHONY: test-run
+test-run: ## Run each image once to test the build result
+	$(DOCKER_RUN) $(DOCKER_TAG)
+	$(DOCKER_RUN) $(DOCKER_TAG_ALPINE)
+	$(DOCKER_RUN) $(DOCKER_TAG_UBUNTU)

README.md

@@ -4,12 +4,15 @@ This is a Docker image containing [pre-commit].
 
 ## Goal
 
-This image provides a base to create derived images containing specific pre-commit tools. Currently, it is based on Ubuntu. This should increase the chance that a derived image can simply use the package manager to install a required package.
+This image provides a base to create derived images containing specific pre-commit tools. There is one image based on Ubuntu and one image based on Alpine.
+
+1. Use the `ubuntu` variant for a higher chance of installing software from the package repository of the operating system.
+1. Use the `alpine` variant if you want a smaller docker image size.
 
 Example derived image Dockerfile:
 
 ```
-FROM petzi/pre-commit:1.15.2
+FROM petzi/pre-commit:1.15.2-ubuntu
 RUN apt-get install -y --no-install-recommends \
     yamllint
 ```
@@ -31,10 +34,14 @@ A git tag will typically look like this.
 
 ### Docker image tag
 
-This repository uses docker hub autobuild and derives many image tags from one build. A docker hub build from git tag `1.15.2-6` will thus create the following docker image tags:
+This repository uses docker hub autobuild and creates many different docker image tags form the same git tag. A docker hub build from git tag `1.15.2-6` will thus create the following docker image tags:
 
 1. `1.15.2`
 1. `1.15.2-6`
+1. `1.15.2-alpine`
+1. `1.15.2-alpine-6`
+1. `1.15.2-alpine.3.9`
+1. `1.15.2-alpine.3.9-6`
 1. `1.15.2-ubuntu`
 1. `1.15.2-ubuntu-6`
 1. `1.15.2-ubuntu.18.10`