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

Cirrus CI

https://cirrus-ci.org

Semaphore CI

https://semaphoreci.com
Unique feature

FreeBSD support

Autoscaling made easy / Great CLI

Type of product

SaaS / On Premise

SaaS

Offers a free plan

Yes

Free for open source projects

Yes

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

Yes

Besides the seat (per-user access) you need to buy compute credits for running the build, priced differently depending on the machine you're running builds on.

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

N/A

Not clear if they offer any real SLA on support.

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 optimal way with Knapsack Pro

Yes

There are limits on how many tasks can be run in parallel for the free tier builds: https://cirrus-ci.org/faq/#are-there-any-limits

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 optimal way with Knapsack Pro

N/A

N/A

Containers support / Build environment

Yes

Allows containers or VMs for every major operating system.

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

Yes

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

N/A

Yes

Self-hosted option

Yes

No

Hosted plans / SaaS

Yes

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

Defined via YML config files

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.

N/A

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?

N/A

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.

No (partial)

No specific support from what I can gather, but it does provide documentation for Ruby, including integration with the knapsack_pro gem.

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

No

No specific support and no documentation on setting up a CI/CD process for a Javascript project.

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

Integrates well with GitHub - the whole CI/CD process starts with a commit to a GitHub repo.

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

Provides a pretty nifty GraphQL API which allows querying the Cirrus CI Schema, as well as webhooks support for other types of custom integrations (such as Slack or IRC notifications, for example). They also added support for GitHub actions

No

Auditing

N/A

From what we can tell, there's no specific support for auditing changes in the Cirrus CI config (other than what is traceable via git commits to the YML config file)

Yes

Additional notes

Seems to be used by companies with a solid engineering background (Google)

List of features is based on Semaphore 2.0

How to run parallel tests on Cirrus CI and Semaphore CI
to execute 1-hour test suite in 2 minutes?

How it works

1. Install Knapsack Pro client in your project


2. Add Knapsack Pro client to your current CI server and run your tests in parallel



3. Update your CI server config file to run tests in parallel with Knapsack Pro

Knapsack Pro in Queue Mode will split tests in a dynamic way across parallel CI nodes to ensure each CI node finish work at a similar time. Thanks to that your CI build time is as fast as possible. It works with many supported CI servers.

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Get faster feedback from Cirrus CI and Semaphore CI server

  • save time & money
  • deliver features faster
  • catch errors earlier

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

Semaphore CI parallelism integration

Introduction to CI parallelisation with Knapsack Pro

Run tests in parallel on Cirrus CI and Semaphore CI in optimal way and avoid bottleneck parallel jobs.

How much can you save with faster tests
on Cirrus CI and Semaphore CI?

minutes
$

Monthly you can save hours
and up to $
on faster development cycle.

Features that make your tests perform better

  • Queue mode see video

    Dynamic tests allocation across Cirrus CI and Semaphore CI parallel jobs. Autobalance tests to get optimal test suite split betweeen CI nodes.

  • Regular mode see video

    Test suite split based on time execution. Generates subset of test suite per CI node before running tests.

  • Fallback mode

    Network issues? Not a problem, run tests anyway! Auto switch to the fallback mode to not depend on Knapsack Pro API.

  • All supported test runners

    Ruby: RSpec, Minitest, Test::Unit, Cucumber, Spinach, Turnip.

    JavaScript: Cypress.io, Jest

    Do you use different programming language or test runner? Let us know in the poll

Discover all features or see
how to use Knapsack Pro with your CI

Trusted solution

Join the teams optimizing their tests with Knapsack Pro.

We've been really enjoying Knapsack Pro, it's been saving us a ton of time.

Devin Brown Software Engineer at Pivotal

This is a fantastic product, it's been a total game-changer for us.

Geoff Harcourt CTO at CommonLit

We are using CircleCI and we noticed that builds were being limited by the slowest parallelized container. Knapsack Pro was really east to setup and we saw huge improvements right away. Thank you for making this tool!

Martin Sieniawski Software Engineer at Collage

Knapsack Pro has helped us build an insanely fast and scaleable build pipeline with almost no setup or maintenance.

Tim Lucas Co-founder of buildkite.com

Knapsack Pro saves us hours of engineer waiting time every week, and is the best solution for keeping our tests load balanced that we've used to date.

Michael Amygdalidis Senior Software Engineer at Popular Pays

I just logged into my account expecting it to say that I needed to add a credit card and was so surprised and delighted to see the trial doesn't count usage by calendar days but by testing days! This is incredible! I love it!!!

I just wanted to say that I really appreciate that small but very huge feature. Thank you for being so thoughtful :)

Shannon Baffoni Senior Software Engineer
at Blue Bottle Coffee

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