Upgrade the exist kubernetes (K8S) cluster

Kubespray handles upgrades the same way it handles initial deployment. That is to say that each component is laid down in a fixed order.

Reduce and optimize Ruby on Rails, PostgreSQL Docker Image size

Building small docker containers can improve performance in builds/pulls and security of the application. It’s easy to start reducing the size of your rails docker image by utilizing small base images and the multi-stage builds pattern.

Prerequisites

• Docker

  Docker is a tool to build safer, share wider, run faster: New updates to our product subscriptions.

  See Empowering App Development for Developers | Docker - https://www.docker.com/
  to learn more.

Create a Rails project with PostgreSQL.

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$ rails new myapp -d postgresql

Ingore files by .dockerignore

you should add a .dockerignore file to your code base, which works pretty much the same way the .gitignore file does. In addition to copying over the contents of your .gitignore file, you might want to include the .git/ directory as well to the list of files ignored by Docker.

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.dockerignore
.git/

Dockerfile
log/
tmp/

See .dockerignore file | Dockerfile reference | Docker Documentation - https://docs.docker.com/engine/reference/builder/#dockerignore-file to learn more.

Mininal Ruby Image - Ruby Alpine

Alpine Linux is a Linux distribution built around musl libc and BusyBox. The image is only 5 MB in size and has access to a package repository that is much more complete than other BusyBox based images. This makes Alpine Linux a great image base for utilities and even production applications. Read more about Alpine Linux here - https://alpinelinux.org/about/ and you can see how their mantra fits in right at home with Docker images.

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FROM ruby:alpine
# FROM ruby:3.0.2-alpine

Multi-stage Builds

Multistage builds are useful to anyone who has struggled to optimize Dockerfiles while keeping them easy to read and maintain.

With multi-stage builds, you use multiple FROM statements in your Dockerfile. Each FROM instruction can use a different base, and each of them begins a new stage of the build. You can selectively copy artifacts from one stage to another, leaving behind everything you don’t want in the final image. To show how this works, let’s adapt the Dockerfile from the previous section to use multi-stage builds.

Make Base Image

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# Dockerfile

ARG RUBY_VERSION=3.0.2
FROM ruby:${RUBY_VERSION}

LABEL maintainer="Benjamin CloudoLife <[email protected]>"

RUN apk --no-cache --update add \
    libcurl \
    postgresql-client \
    tzdata

ARG APP_HOME=/app
RUN mkdir -p ${APP_HOME}
ENV APP_HOME ${APP_HOME}
WORKDIR ${APP_HOME}

ARG RAILS_ENV=production
ENV RAILS_ENV ${RAILS_ENV}

RUN gem update --system

COPY entrypoint.sh /usr/sbin/entrypoint.sh
ENTRYPOINT ["entrypoint.sh"]

CMD ["bundle", "exec", "rails", "s", "-b", "0.0.0.0"]

Build and tag:

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$ docker build . -t cloudolife/ruby-postgresql:base-3.0.2-alpine

Make Builder Image

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# Dockerfile-builder-alpine

ARG RUBY_VERSION=base-3.0.2-alpine
FROM cloudolife/ruby-postgresql:${RUBY_VERSION}

LABEL maintainer="Benjamin CloudoLife <[email protected]>"

RUN apk --no-cache --update add \
    build-base \
    git \
    # nodejs \
    openssh \
    postgresql-dev
    # yarn

Build and tag:

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$ docker build . -t cloudolife/ruby-postgresql:builder-3.0.2-alpine

Multiple Stages

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# Dockerfile

# Stage Build
ARG RUBY_VERSION=builder-3.0.2-alpine
FROM cloudolife/ruby-postgresql:${RUBY_VERSION} AS Builder

LABEL maintainer="Benjamin CloudoLife <[email protected]>"

COPY . .

RUN bundle config set --local without 'development test' && \
    bundle -j3 --retry 3

# Stage Run
ARG RUBY_VERSION=base-3.0.2-alpine
FROM cloudolife/ruby-postgresql:${RUBY_VERSION}

LABEL maintainer="Benjamin CloudoLife <[email protected]>"

# Copy app with gems from build stage
COPY --from=Builder /usr/local/bundle/ /usr/local/bundle/
COPY --from=Builder /app /app

RUN bin/rails db:migrate

Build and tag:

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$ docker build . -t cloudolife/ruby-postgresql-example:3.0.2-alpine

Remove Cache and unnecessary file

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RUN rm -rf /usr/local/bundle/cache/*.gem && \
    find /usr/local/bundle/gems/ -name "*.c" -delete && \
    find /usr/local/bundle/gems/ -name "*.o" -delete

Build and tag:

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$ docker build . -t cloudolife/ruby-postgresql-example:3.0.2-alpine

Conclusion

Dockerfile-base-alpine:

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# Dockerfile-base-alpine

ARG RUBY_VERSION=3.0.2
FROM ruby:${RUBY_VERSION}

LABEL maintainer="Benjamin CloudoLife <[email protected]>"

RUN apk --no-cache --update add \
    libcurl \
    postgresql-client \
    tzdata

ARG APP_HOME=/app
RUN mkdir -p ${APP_HOME}
ENV APP_HOME ${APP_HOME}
WORKDIR ${APP_HOME}

ARG RAILS_ENV=production
ENV RAILS_ENV ${RAILS_ENV}

RUN gem update --system

COPY entrypoint.sh /usr/sbin/entrypoint.sh
ENTRYPOINT ["entrypoint.sh"]

CMD ["bundle", "exec", "rails", "s", "-b", "0.0.0.0"]

Dockerfile-builder-alpine

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# Dockerfile-builder-alpine

ARG RUBY_VERSION=base-3.0.2-alpine

FROM cloudolife/ruby-postgresql:${RUBY_VERSION}

LABEL maintainer="Benjamin CloudoLife <[email protected]>"

RUN apk --no-cache --update add \
    build-base \
    git \
    openssh \
    postgresql-dev

ruby-postgresql-example

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# Dockerfile

# Stage Build
ARG RUBY_VERSION=builder-3.0.2-alpine
FROM cloudolife/ruby-postgresql:${RUBY_VERSION} AS Builder

LABEL maintainer="Benjamin CloudoLife <[email protected]>"

# COPY Gemfile* package.json yarn.lock ./
# RUN bundle --without development test -j3 --retry 3
RUN yarn install

COPY . .

RUN bundle config set --local without 'development test' && \
    bundle -j3 --retry 3

RUN bin/rails db:migrate
# RUN bin/rails assets:precompile


# Stage Run
ARG RUBY_VERSION=base-3.0.2-alpine
FROM cloudolife/ruby-postgresql:${RUBY_VERSION}

LABEL maintainer="Benjamin CloudoLife <[email protected]>"

# Copy app with gems from build stage
COPY --from=Builder /usr/local/bundle/ /usr/local/bundle/
COPY --from=Builder /app /app

RUN rm -rf /usr/local/bundle/cache/*.gem && \
    find /usr/local/bundle/gems/ -name "*.c" -delete && \
    find /usr/local/bundle/gems/ -name "*.o" -delete

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$ docker build -f Dockerfile . -t cloudolife/ruby-postgresql-example:3.0.2-alpine

Show Image size and history

docker history

Show the history of an image

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Usage
 docker history [OPTIONS] IMAGE

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docker history cloudolife/ruby-postgresql:builder-3.0.2-alpine
IMAGE          CREATED        CREATED BY                                      SIZE      COMMENT
42681291d509   28 hours ago   RUN /bin/sh -c apk --no-cache --update add  …   523MB     buildkit.dockerfile.v0
<missing>      28 hours ago   LABEL maintainer=Benjamin CloudoLife <benjam…   0B        buildkit.dockerfile.v0
<missing>      28 hours ago   CMD ["bundle" "exec" "rails" "s" "-b" "0.0.0…   0B        buildkit.dockerfile.v0
<missing>      28 hours ago   ENTRYPOINT ["entrypoint.sh"]                    0B        buildkit.dockerfile.v0
<missing>      28 hours ago   COPY entrypoint.sh /usr/sbin/entrypoint.sh #…   173B      buildkit.dockerfile.v0
<missing>      28 hours ago   RUN |2 APP_HOME=/app RAILS_ENV=production /b…   24.2MB    buildkit.dockerfile.v0
<missing>      28 hours ago   ENV RAILS_ENV=production                        0B        buildkit.dockerfile.v0
<missing>      28 hours ago   ARG RAILS_ENV=production                        0B        buildkit.dockerfile.v0
<missing>      28 hours ago   WORKDIR /app                                    0B        buildkit.dockerfile.v0
<missing>      28 hours ago   ENV APP_HOME=/app                               0B        buildkit.dockerfile.v0
<missing>      28 hours ago   RUN |1 APP_HOME=/app /bin/sh -c mkdir -p ${A…   0B        buildkit.dockerfile.v0
<missing>      28 hours ago   ARG APP_HOME=/app                               0B        buildkit.dockerfile.v0
<missing>      28 hours ago   RUN /bin/sh -c apk --no-cache --update add  …   6.12MB    buildkit.dockerfile.v0
<missing>      28 hours ago   LABEL maintainer=Benjamin CloudoLife <benjam…   0B        buildkit.dockerfile.v0
<missing>      3 days ago     /bin/sh -c #(nop)  CMD ["irb"]                  0B
<missing>      3 days ago     /bin/sh -c mkdir -p "$GEM_HOME" && chmod 777…   0B
<missing>      3 days ago     /bin/sh -c #(nop)  ENV PATH=/usr/local/bundl…   0B
<missing>      3 days ago     /bin/sh -c #(nop)  ENV BUNDLE_SILENCE_ROOT_W…   0B
<missing>      3 days ago     /bin/sh -c #(nop)  ENV GEM_HOME=/usr/local/b…   0B
<missing>      3 days ago     /bin/sh -c set -eux;   apk add --no-cache --…   43.4MB
<missing>      2 months ago   /bin/sh -c #(nop)  ENV RUBY_DOWNLOAD_SHA256=…   0B
<missing>      2 months ago   /bin/sh -c #(nop)  ENV RUBY_VERSION=3.0.2       0B
<missing>      2 months ago   /bin/sh -c #(nop)  ENV RUBY_MAJOR=3.0           0B
<missing>      2 months ago   /bin/sh -c #(nop)  ENV LANG=C.UTF-8             0B
<missing>      2 months ago   /bin/sh -c set -eux;  mkdir -p /usr/local/et…   45B
<missing>      2 months ago   /bin/sh -c set -eux;  apk add --no-cache   b…   11.4MB
<missing>      2 months ago   /bin/sh -c #(nop)  CMD ["/bin/sh"]              0B
<missing>      2 months ago   /bin/sh -c #(nop) ADD file:aad4290d27580cc1a…   5.6MB

See docker history | Docker Documentation - https://docs.docker.com/engine/reference/commandline/history/ to learn more.

Dive

Dive is a tool for exploring a docker image, layer contents, and discovering ways to shrink the size of your Docker/OCI image.

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$ dive cloudolife/ruby-postgresql:builder-3.0.2-alpine

See wagoodman/dive: A tool for exploring each layer in a docker image - https://github.com/wagoodman/dive to leran more.

Compare Image Size

FAQs

failed to solve with frontend dockerfile.v0: failed to create LLB definition: circular dependency detected on stage: vendor

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failed to solve with frontend dockerfile.v0: failed to create LLB definition: circular dependency detected on stage: vendor
make: *** [docker-build-tag] Error 1

TODO

References

[1] Building Docker images, the performant way | Georg Ledermann, Full Stack Developer: Ruby on Rails, Vue.js - https://ledermann.dev/blog/2020/01/29/building-docker-images-the-performant-way/

[2] Best practices when writing a Dockerfile for a Ruby application | Florin Lipan - https://lipanski.com/posts/dockerfile-ruby-best-practices

[3] Dockerize Rails, the lean way | Georg Ledermann, Full Stack Developer: Ruby on Rails, Vue.js - https://ledermann.dev/blog/2018/04/19/dockerize-rails-the-lean-way/

[4] Ruby on Rails — Smaller docker images | by Lemuel Barango | Medium - https://medium.com/@lemuelbarango/ruby-on-rails-smaller-docker-images-bff240931332

[5] Reduce your Docker images (an example with Ruby) - DEV Community - https://dev.to/caduribeiro/reduce-your-docker-images-an-example-with-ruby-30db

[6] Alpine - Official Image | Docker Hub - https://hub.docker.com/_/alpine

[7] Ruby - Official Image | Docker Hub - https://hub.docker.com/_/ruby

[8] Use multi-stage builds | Docker Documentation - https://docs.docker.com/develop/develop-images/multistage-build/

[9] .dockerignore file | Dockerfile reference | Docker Documentation - https://docs.docker.com/engine/reference/builder/#dockerignore-file

[10] docker history | Docker Documentation - https://docs.docker.com/engine/reference/commandline/history/

[11] wagoodman/dive: A tool for exploring each layer in a docker image - https://github.com/wagoodman/dive

[12] Empowering App Development for Developers | Docker - https://www.docker.com/

MapStruct

MapStruct is a code generator that greatly simplifies the implementation of mappings between Java bean types based on a convention over configuration approach.

The generated mapping code uses plain method invocations and thus is fast, type-safe and easy to understand.

K3S on Raspberry Pi

K3S is the certified Kubernetes distribution built for IoT & Edge computing.

Raspberry Pi 4 Model (or B) is your tiny, dual-display, desktop computer …and robot brains, smart home hub, media centre, networked AI core, factory controller, and much more.

Kubernetes (K8S) Cluster on AlmaLinux 8 with Containerd Container Runtime

This article show how to install Kubernetes (K8S) cluster on AlmaLinux 8 with Containerd Container Runtime.

Elastic APM Server

Elastic APM is the free and open application performance monitoring. It monitor, detect, and diagnose complex application performance issues to maintain an expected level of service.

This article is about how to use Pulumi, kubernetes (K8S) provider, Helm Chart and TypeScript SDK to deploy Elastic APM within Kubernetes (K8S).

Elastic Kibana

Elastic Kibana is a free and open user interface that lets you visualize your Elasticsearch data and navigate the Elastic Stack. Do anything from tracking query load to understanding the way requests flow through your apps.

This article is about how to use Pulumi, kubernetes (K8S) provider, Helm Chart and TypeScript SDK to deploy Elastic Kibana within Kubernetes (K8S).

Elastic Elasticsearch

Elasticsearch is the distributed, RESTful search and analytics engine at the heart of the Elastic Stack. You can use Elasticsearch to store, search, and manage data for:

• Logs

• Metrics

• A search backend

• Application monitoring

• Endpoint security

… and more!

This article is about how to use Pulumi, kubernetes (K8S) provider, Helm Chart and TypeScript SDK to deploy Elasticsearch within Kubernetes (K8S).

TelephoneNumber

TelephoneNumber is global phone number validation gem based on Google’s libphonenumber library google/libphonenumber: Google’s common Java, C++ and JavaScript library for parsing, formatting, and validating international phone numbers. - https://github.com/google/libphonenumber.

Visual Studio Code Java, Spring, Spring Boot extensions

Visual Studio Code is an ideal lightweight development environment for Spring Boot application developers and there are several useful VS Code extensions including:

• Spring Boot Extension Pack - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=Pivotal.vscode-boot-dev-pack

  Spring Boot Extension Pack that includes all of the extensions follow:

  • Spring Boot Tools - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=Pivotal.vscode-spring-boot

  • Spring Initializr Java Support - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-spring-initializr

  • Spring Boot Dashboard - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-spring-boot-dashboard

• Extension Pack for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-pack

  Extension Pack for Java that includes all of the extensions follow:

  • Language Support for Java™ by Red Hat - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=redhat.java

  • Test Runner for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-test

  • Project Manager for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-dependency

  • Maven for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-maven

  • Debugger for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-debug

• Gradle for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-gradle

Prerequites

• Java Development Kit (JDK) version

  The Java Development Kit (JDK) is a distribution of Java Technology by Oracle Corporation. It implements the Java Language Specification (JLS) and the Java Virtual Machine Specification (JVMS) and provides the Standard Edition (SE) of the Java Application Programming Interface (API).

  See Microsoft Build of OpenJDK - https://www.microsoft.com/openjdk or Java Downloads | Oracle - https://www.oracle.com/java/technologies/downloads/ to learn more.

Usages

Once you have the extension installed, open the Command Palette (⇧⌘P) and type Spring Initializr to start generating a Maven or Gradle project and then follow the wizard.

See [sts4/vscode-extensions/vscode-spring-boot at main · spring-projects/sts4 - https://github.com/spring-projects/sts4/tree/main/vscode-extensions/vscode-spring-boot#usage] to learn more usges.

References

[1] Spring Boot support in Visual Studio Code - https://code.visualstudio.com/docs/java/java-spring-boot

[2] Language Support for Java™ by Red Hat - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=redhat.java

[3] Test Runner for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-test

[4] Project Manager for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-dependency

[5] Maven for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-maven

[6] Debugger for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-debug

[7] Extension Pack for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-pack

[8] Spring Boot Tools - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=Pivotal.vscode-spring-boot

[9] Spring Boot Dashboard - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-spring-boot-dashboard

[10] Spring Boot Extension Pack - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=Pivotal.vscode-boot-dev-pack

[11] Spring Initializr Java Support - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-spring-initializr

[12] Gradle for Java - Visual Studio Marketplace - https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-gradle

[13] Visual Studio Code - Code Editing. Redefined - https://code.visualstudio.com/

[15] Java | Oracle - https://www.java.com/en/

[15] Java Downloads | Oracle - https://www.oracle.com/java/technologies/downloads/

[16] Java Downloads | Oracle - https://www.oracle.com/java/technologies/downloads/

[17] sts4/vscode-extensions at main · spring-projects/sts4 - https://github.com/spring-projects/sts4/tree/main/vscode-extensions