Pre-built public images

These images are loaded with helpful libraries for CI pipelines.

The Harness Community maintains pre-built, public Docker images that you can use to quickly set up a build environment. These images are heavily extended versions of official Docker images, and they include useful tools for CI pipelines.

The benefits of using pre-built images include:

• Builds start faster: Pre-built images are usually squashed, meaning they have have fewer and smaller layers. These images take less time to download, if they are not already cached on the host. By using pre-built images, your builds start faster.

• Bundled with useful tools: Pre-built images include the minimum utilities required to run most builds on Harness CI along with language- or service-specific tools, such as Bundler for Ruby.

The Harness Community public images are optional images you can use to quickly set up a specific build environment. They are different from Harness CI images, which are essential images used by Harness to run CI pipelines.

Available pre-built images

Available images include a base image and several images for specific languages and services. The language and service images are derived from the base image.

The Docker images are available on the Harness Community Docker Hub.

The source code for the images is available in the Harness Community ci-images GitHub repository.

Common tools

The following tools are installed on all public images:

• autoconf

• build-essential

• bzip2

• ca-certificates

• cmake

• curl

• Docker client

• Docker Compose

• Dockerize

• elixir

• git

• gnupg

• gzip

• jq

• libcurl4-openssl-dev

• libmariadb-dev

• libmariadb-dev-compact

• libpq-dev

• libssl-dev

• libsqlite3-dev

• locales

• make

• net-tools

• netcat

• openssh-client

• parallel

• pkg-config

• postgresql-client

• python3

• python3-pip

• shellcheck

• software-properties-common

• sudo

• tar

• tzdata

• unzip

• vim

• wget

• zip

CI base image

The Harness Community CI base image is an Ubuntu-based lightweight image that installs the minimum utilities required to run most builds on Harness CI, including an Ubuntu Linux OS (22.04), Git, Docker, Docker Compose, Dockerize, curl, ssh, and so on.

To use the base image in a pipeline, reference it in a step's spec.image, for example:

                 spec:
                   connectorRef: YOUR_IMAGE_REGISTRY_CONNECTOR 
                   image: harnesscommunity/base:latest ## Reference the Docker Hub repo, image, and tag.
                   shell: Sh
                   command: sudo npm install -g npm ## This is an example command.

Language-specific images

The Harness Community language images are pre-built images for specific programming languages. Each tag contains a complete version of the specified language, an SDK (if applicable), and any binaries/tools required for Harness CI builds. For example, the Ruby image includes a complete Ruby version, the gem command, and Bundler, among other binaries/tools.

Harness Community language images include:

• Android (2022.10)

• Ruby (3.1.2)

• Node.js (18.9, 18.6, 18.5, 18.4, 18.0, 17.19.1)

• OpenJDK (Java) (18.0.2)

IMAGE VARIANTS

Harness maintains several variants of some language images. This is indicated by a variant suffix, such as -browser, on the image tag.

Image variants are considered in progress and under development.

To use a language image in a pipeline, reference it in a step's spec.image, for example:

                 spec:
                   connectorRef: YOUR_IMAGE_REGISTRY_CONNECTOR 
                   image: harnesscommunity/ruby:latest ## Reference the Docker Hub repo, image, and tag.
                   shell: Sh
                   command: bundle exec rake test ## This is an example command.

Service-specific images

The Harness Community service images are pre-built images for specific services, like databases. In a CI pipeline, configure these images after language images.

Currently, only one service image is available:

• Postgres

To use a service image in a pipeline, reference it in a step's spec.image, for example:

                 spec:
                   connectorRef: YOUR_IMAGE_REGISTRY_CONNECTOR 
                   image: harnesscommunity/postgres:14.5 ## Reference the Docker Hub repo, image, and tag.
                   shell: Sh
                   command: bundle exec rake test ## This is an example command.

Pre-built image updates

The Harness Community updates the pre-built images as needed for bug fixes and enhancements. Updates can impact image functionality in your pipelines. Follow the #continuous-integration channel on Harness Community Slack to get notified about image updates.

Use a specific image tag

The pre-built images are based on the most recent Ubuntu LTS Docker image, and they have the base libraries for the specified language for service. Using the most specific image possible makes your builds more predictable by avoiding incorporating unwanted, upstream changes until you can test them.

For example, instead of using image: harnesscommunity/node:latest, use a specific version number, like node:18.6.

Once you've tested a newer version, you can modify the image tag in your pipeline accordingly.