derrick

README

Derrick

Derrick is a tool to help you containerize application in seconds. Derrick focuses on developer workflow in local development environment. Derrick will inspect your workspace first, then generate definitions and templates to boost your journey to run apps as containerized services. This includes generating Dockerfile for your app, k8s definitions to deploy it, Helm Chart or Kustomize folders for multi-environment setup, Terraform templates to bootstrap your infrastructure resources, CI/CD pipelines to build/test/deploy the whole thing continously. You can use Derrick to set up your DevOps processes in cloud-native way.

Using Derrick is very simple:

1. derrick gen to automatically inspect the workspace and generate the Dockerfile for your application, or
2. derrick list to show all available riggings and pick one via derrick gen -r <rigging> to generate the Dockerfile.
3. Use your favorite text editor to modify the Dockerfile or other manifests before building and shipping the containers.
4. Integrate into your workflow and have fun.

Architecture

Derrick has basically the following processing layers:

• Rigging: It bundles language specific logic into a package and hooks into derrick's lifecycle to detect the codebase and generate the Dockerfile.
• AutoParam: This is called and reused by Riggings to detect dev environment and fill template with detected parameters like Go version, package name, etc.

Language Support

Here is the list of frameworks passed the tests. If you want to support more languages and frameworks, please submit an issue.

• Java
• PHP
• PYTHON
• Golang
• NodeJs

Quick Start

Installation

Build derrick binary:

make build
cp _bin/derrick /usr/local/bin/

Verify it in command line:

$ derrick -h
🐳 A tool to help you containerize applications in seconds

Usage:
  derrick [command]

Available Commands:
  gen         Inspect the application and generate Dockerfile
  help        Help about any command
  list        List all available riggings to inspect the applications
  version     Prints out build version information

Flags:
  -h, --help   help for derrick

Use "derrick [command] --help" for more information about a command.

Show available riggings

$ derrick list

Available riggings:
	golang
	java
	nodejs
	php
	python

Build golang application

• Clone a sample project

Clone this sample project into your Golang path.

$ git clone git@github.com:zzxwill/golang-web-application.git
$ cd golang-web-application

• Compile the application

$ derrick gen
Successfully detected your platform is 'golang'
Successfully generated: Dockerfile
Successfully generated: derrick.conf

• (Optional) You can also manually specify to use golang rigging:

$ derrick gen -r golang

Build Java application

Clone a Java application, and build it.

$ git clone https://github.com/hongchaodeng/simple-java-maven-app.git
$ cd simple-java-maven-app
$ derrick gen
Successfully detected your platform is 'java'
Successfully generated: Dockerfile
Successfully generated: chart/Chart.yaml
Successfully generated: chart/.helmignore
Successfully generated: chart/templates/NOTES.txt
Successfully generated: chart/templates/deployment.yaml
Successfully generated: chart/templates/_helpers.tpl
Successfully generated: chart/templates/hpa.yaml
Successfully generated: chart/templates/ingress.yaml
Successfully generated: chart/templates/service.yaml
Successfully generated: chart/templates/serviceaccount.yaml
Successfully generated: chart/templates/tests/test-connection.yaml
Successfully generated: chart/values-production.yaml
Successfully generated: chart/values-staging.yaml
Successfully generated: chart/values.yaml
Successfully generated: kubernetes/deployment.yaml
Successfully generated: kustomize/base/deployment.yaml
Successfully generated: kustomize/overlays/production/deployment.yaml
Successfully generated: kustomize/overlays/production/kustomization.yaml
Successfully generated: kustomize/overlays/staging/deployment.yaml
Successfully generated: kustomize/overlays/staging/kustomization.yaml
Successfully generated: derrick.json

You can check sample outputs here:

• Dockerfile
• chart
• kustomize
• kubernetes

Check the Dockerfile:

$ cat Dockerfile
# First stage: build environment
FROM maven:3.5.0-jdk-8-alpine AS builder

# To resolve dependencies first without re-download everytime
ADD ./pom.xml pom.xml
# By default mvn use '~/.m2' which could be cleaned up, change to use './.m2'
RUN mvn install -Dmaven.repo.local=./.m2

ADD ./src src/
# package jar
RUN mvn install -Dmaven.test.skip=true -Dmaven.repo.local=./.m2

# Second stage: runtime environment
From openjdk:8

# copy jar from the first stage
COPY --from=builder target/my-app-1.0-SNAPSHOT.jar my-app-1.0-SNAPSHOT.jar

# MY_CPU_LIMIT could be imported via downward API automatically in Kubernetes Deployment.
CMD ["java", \
  "-XX:InitialRAMPercentage=75", \
  "-XX:MaxRAMPercentage=75", \
  "-XX:MinRAMPercentage=25", \
  "-XX:ActiveProcessorCount=$MY_CPU_LIMIT", \
  "-jar", "my-app-1.0-SNAPSHOT.jar"]

We can see the Dockerfile that:

• It separates build and runtime stages. It uses openjdk which is the popular and standard base for runtime environment.
• It has optimized caching of dependencies.
• It automatically parses artifact name from pom.xml .

It also generates a couple of Kubernetes deployment manifests:

kubernetes/
chart/
kustomize/

Let's take a look at the helm chart it generates. We can see the final deployment manifests by running the following command:

$ cd chart/
$ helm template test .
...
apiVersion: apps/v1
kind: Deployment
metadata:
  name: test-simple-java-maven-app
  labels:
    helm.sh/chart: simple-java-maven-app-0.1.0
    app.kubernetes.io/name: simple-java-maven-app
    app.kubernetes.io/instance: test
    app.kubernetes.io/version: "1.16.0"
    app.kubernetes.io/managed-by: Helm
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: simple-java-maven-app
      app.kubernetes.io/instance: test
  template:
    metadata:
      labels:
        app.kubernetes.io/name: simple-java-maven-app
        app.kubernetes.io/instance: test
    spec:
      serviceAccountName: test-simple-java-maven-app
      containers:
        - name: simple-java-maven-app
          image: "your-image"
          imagePullPolicy: IfNotPresent
          env:
            - name: MY_CPU_REQUEST
              valueFrom:
                resourceFieldRef:
                  containerName: java-app
                  resource: requests.cpu
            ...
          ports:
            - name: http
              containerPort: 80
              protocol: TCP
          livenessProbe:
            tcpSocket:
              port: 80
            ...
          readinessProbe:
            ...
          resources:
            limits:
              cpu: 2
              memory: 1500M
            requests:
              cpu: 1
              memory: 1500M

Let's take a look at the kustomize directories it generates. We can see the final deployment manifests by running the following command:

$ kustomize build kustomize/overlays/prod
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: simple-java-maven-app
    tier: production
  name: prod-simple-java-maven-app
spec:
  selector:
    matchLabels:
      app: simple-java-maven-app
      tier: production
  template:
    metadata:
      labels:
        app: simple-java-maven-app
        tier: production
    spec:
      containers:
      - ...
        image: your-image
        name: java-app
        resources:
          limits:
            cpu: 2
            memory: 2000M
          requests:
            cpu: 1
            memory: 1500M

Note that the above deployment manifests are samples for you to quickly bootstrap. To make it work you still need to build the actual image, fill the image name. Additionally, if you deploy it on Alibaba cloud and want to integrate with AHAS/ARMS/MSE middlewares, you also need to fill your app name in the annotations.

Build NodeJS application

$ git clone git@github.com:zzxwill/nodejs-web-application.git
$ cd nodejs-web-application
$ derrick gen

License

This software is released under the Apache 2.0 license.