Knapsack Pro

Jenkins vs Semaphore CI comparison of Continuous Integration servers
What are the differences between Jenkins and Semaphore CI?

Jenkins

https://jenkins.io

Semaphore CI

https://semaphoreci.com
Unique feature

Plugins

Autoscaling made easy / Great CLI

Type of product

Self-hosted / On Premise

SaaS

Offers a free plan

Yes

Free, open source software

Yes

1,300 service minutes every month. Plans to release a free tier for open source projects.

Predictable pricing

Yes

Jenkins is free software, the only costs are those assigned to running your infrastructure.

Yes

Semaphore doesn't have traditional pricing tiers, instead it lists the types of machines you can use and their pricing per second of service. They plan to release an annual plan at some point.

Support / SLA

No (partial)

No official support available, or SLAs. However, Jenkins' popularity ensures you'll find support in various places (official Jenkins forum, IRC, StackOverflow etc.)

N/A

Not clear if they offer any real SLA on support.

Paralellism
Every CI servers tends to address this differently (parallel, distributed, build matrix). Some of it is just marketing, and some is just nuance. For this table, parallel means that tasks can be run concurrently on the same machine, distributed means that tasks can be scaled horizontally, on multiple machines
How to split tests in parallel in the optimal way with Knapsack Pro

Yes (partial)

Jenkins allows builds to be run in parallel, but all builds share the same environment and there can be issues arising from shared resources such as the filesystem.

Yes

Allows defining a custom build matrix such that your build can be parallelized accross several different environments.

Distributed builds
distributed means that tasks can be scaled horizontally, on multiple machines
How to split tests in parallel in the optimal way with Knapsack Pro

Yes (partial)

Jenkins has a concept of master server and agents, for distributing builds, but setting that up requires quite a bit of manual work from a sysadmin, compared to other options.

N/A

Containers support / Build environment

No (partial)

By default, Jenkins runs all builds in the same environment as the build server itself, which can lead to numerous issues and is generally not a good practice. Some plugins address this issue, but they need to be manually installed.

Yes

Allows running builds inside docker containers

Analytics / Status overview
Analytics and overview referrs to the ability to, at a glance, see what's breaking (be it a certain task, or the build for a specific project)

Yes

Available via the Blue Ocean project (part of Jenkins): https://jenkins.io/doc/book/blueocean/dashboard/#dashboard

Yes

Management support
How easy is it to manage users / projects / assign roles and permissions and so on

No

In practice, for Jenkins it usually means that there's someone solely in charge of the Jenkins instance (configuration, management). Collaboration features built into other similar products are lacking, as are governance features (no easy way to tell from Jenkins alone _who_ is responsabile for a broken build, for example), even if your Version Control Server of choice can give that information (via `git blame` for example).

Yes

Self-hosted option

Yes

Jenkins is Open Source Software, and self-hosting is the only way to use it.

No

Hosted plans / SaaS

No

Only available for self-hosting.

Yes

Build pipelines
A continuous delivery pipeline is a description of the process that the software goes through from a new code commit, through testing and other statical analysis steps all the way to the end-users of the product.

Yes

Offers extensive support for custom pipelines, either through the Jenkins Pipeline DSL, written in a Jenkinsfile, either through the Web UI. Also, their Blue Ocean project is a great tool for building pipelines: https://jenkins.io/projects/blueocean/

Yes

Allows defining complex build workflows with ease

Reports
Reports are about the abilty to see specific reports (like code coverage or custom ones), but not necesarily tied in into a larger dashboard.

Yes

Has ready-made integrations for standard reports such as JUnit test results.

N/A

Ecosystem
Besides the official documentation and software, is there a large community using this product? Are there any community-driven tools / plugins that you can use?

> 1000 community plugins

Thanks to it's popularity, there's a large selection of available plugins for Jenkins. They can all be easily browsed over at https://plugins.jenkins.io/. The downside is that almost anything you want to do in Jenkins requires installing a plugin, even core functionality such as parsing output or checking out source code.

N/A

Specific language support: Ruby
Some CI servers have built-in support for parsing RSpec or Istanbul output for example and we mention those. Some others make it even easier by detecting Gemfiles or package.json and automate parts of the process for the developer.

Yes (Partial)

RSpec and Cucumber test suites can be integrated into Jenkins thanks to the large pool of available plugins and Ruby gems. Jenkins only understands the JUnit format natively.

Yes

Provides rich documentation on integrating Semaphore CI in Ruby projects. Also provides sudo access if you need to install system dependencies or C extensions.

Specific language support: JavaScript

Yes (Partial)

Jest, AVA and other test suites can be integrated into Jenkins thanks to the large pool of available plugins and NPM packages. Jenkins only understands the JUnit format natively.

Yes

Provides rich documentation on integrating Semaphore CI in Javascript projects

Integrations
1st party support for common tools (like Slack notifications, various VCS platforms, etc)

Yes

Allows integrations with other tools (ie: Slack, GitHub) or communication protocols (ie: email) via it's rich plugin suite

Yes

Integration with GitHub and Slack. They allow building iOS projects via their macOS Mojave VM image.

API
Custom integreation is available, via an API or otherwise, it's mentioned separately as it allows further customization than any of the Ecosystem/Integration options

Yes

For use-cases that the +1k plugins don't cover, the Jenkins Remote API is yet another way to integrate Jenkins into your favorite tools or internal products.

No

Auditing

No

Jenkins instances are really managed by a sole user with administrative privileges. This can lead to various issues when it comes to audit trails / accountability.

Yes

Additional notes

List of features is based on Semaphore 2.0

Continuous delivery pipelines in Jenkins and CI parallelisation

Running Rails tests in parallel on Semaphore CI 2.0 with dynamic test files split

Jenkins parallelism integration

Semaphore CI parallelism integration

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