Open-Source DevOps · semaphoreui

semaphore

Semaphore UI is a modern web dashboard for running and managing Ansible, Terraform, OpenTofu, and PowerShell automation workflows. It simplifies multi-tool DevOps orchestration, scheduling, and task execution without requiring terminal access.

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Source: GitHub — github.com/semaphoreui/semaphore

13.9k

GitHub stars

1.3k

Forks

Primary language

MIT

License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

Field	Value
Repository	semaphoreui/semaphore
Owner	semaphoreui
Primary language	Go
License	MIT — OSI-approved
Stars	13.9k
Forks	1.3k
Open issues	1k
Latest release	v2.18.20 (2026-07-05)
Last updated	2026-07-07
Source	https://github.com/semaphoreui/semaphore

What semaphore is

Go-based web application providing REST API and UI for orchestrating IaC (Terraform/OpenTofu/Terragrunt), configuration management (Ansible), and scripting (PowerShell/Bash). Supports multi-project isolation, task templating, inventory management, variable groups, and scheduling via cron-like expressions.

Quickstart

Get the semaphore source

Clone the repository and explore it locally.

terminalbash

1git clone https://github.com/semaphoreui/semaphore.git2cd semaphore3# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

Multi-tool DevOps orchestration

Centralized control panel for teams running Ansible, Terraform, and OpenTofu in production. Eliminates need for separate UIs or CLI workflows while maintaining audit trails and role-based access.

Self-service deployment platform

Enable non-terminal users (ops, business teams) to trigger infrastructure changes and deployments on demand through web UI. Reduce deployment toil and human error.

Scheduled infrastructure automation

Run recurring IaC tasks, compliance scans, or disaster recovery workflows on fixed schedules. Integrate notifications for task success/failure.

Implementation considerations

Database requirement: SQLite (embedded), PostgreSQL, or MySQL. Plan persistence and backup strategy; SQLite is simplest for small teams, PostgreSQL recommended for production.
Task execution model: Semaphore orchestrates tool execution (Ansible, Terraform) on target hosts; it does not execute them itself. Ensure SSH/WinRM access and tool installations are pre-configured.
Secrets management: Variable Groups store sensitive data; evaluate whether integration with HashiCorp Vault, AWS Secrets Manager, or similar is needed for your compliance posture.
Scale considerations: Open issue count (1035) and last-checked release date suggest active development; test performance with your expected task volume and concurrency.
Docker deployment is recommended per README; binary and Snap packages also available. Plan resource allocation (CPU, memory) based on task parallelism and team size.

When to avoid it — and what to weigh

Pure CI/CD pipeline execution — If your primary need is GitHub Actions, Jenkins, or GitLab CI integration, Semaphore is a UI layer, not a CI/CD engine. Consider native CI/CD platforms instead.
Real-time log streaming at scale — Semaphore is designed for task management and orchestration. If you need centralized log aggregation and streaming for thousands of concurrent tasks, ELK or similar is better suited.
Complex multi-tenant SaaS without custom development — While Semaphore supports projects and access control, deep multi-tenancy isolation, billing, and compliance features are not built-in; custom work is needed.
Air-gapped environments without community support confidence — Open Issue count is high (1035). If you depend on rapid vendor patches, assess maintenance capacity and response time expectations in your environment.

License & commercial use

MIT License (MIT). Permissive OSI-approved license allowing commercial use, modification, and redistribution with minimal restrictions.

MIT license permits commercial use without explicit permission or royalty. You may use, modify, and redistribute Semaphore in proprietary or SaaS products. Recommend including a LICENSE file in distributions and reviewing any modified source code for compliance. No warranty or liability indemnification is provided; evaluate your risk tolerance.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

Signal	Assessment
Maintenance	Active
Documentation	Adequate
License clarity	Clear
Deployment complexity	Low
DEV.co fit	Strong
Assessment confidence	High

Security considerations

Semaphore stores sensitive data (SSH keys, API tokens, cloud credentials) in Variable Groups; encryption-at-rest and encryption-in-transit must be verified. No mention of audit logging, two-factor authentication, or secrets rotation in excerpt. Access control is role-based but RBAC model details are not documented here. Database security (SQLite in dev, PostgreSQL in prod) depends on configuration; plan network isolation and credential hardening. Source code review and security testing recommended before handling production secrets.

Alternatives to consider

Ansible AWX

Official Ansible UI with deeper native integration, RBAC, and enterprise support. Higher operational overhead; lacks Terraform/OpenTofu native support.

Terraform Cloud / Terraform Enterprise

Purpose-built for Terraform state, runs, and collaboration. Tight Terraform integration; less suitable for Ansible/PowerShell; managed/SaaS model.

Jenkins with UI plugins (Blue Ocean, etc.)

Mature CI/CD orchestration with broad tool ecosystem. Heavier operational footprint; not purpose-designed for IaC/DevOps task management.

Software development agency

Build on semaphore with DEV.co software developers

Review deployment requirements, database configuration, and secrets management strategy. Test with a pilot project (Docker or VM marketplace image) before production rollout. Assess API and audit-logging depth for compliance needs.

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semaphore FAQ

Can Semaphore run multiple tools in a single workflow?

Yes. Task Templates support chaining; you can define a sequence of Ansible, Terraform, and bash steps within one task or across scheduled tasks in a project.

Is state management (e.g., Terraform state) built into Semaphore?

No. Semaphore is a task orchestrator and UI. Terraform state must be stored externally (S3, Terraform Cloud, local disk). Semaphore invokes `terraform` CLI.

Does Semaphore support multi-tenancy or SaaS deployment?

Semaphore supports projects and access control within a single instance. Multi-tenancy for billing/isolation is not built-in; custom work or multiple instances required. Official SaaS offering (Semaphore Cloud) exists but not detailed here.

What databases are supported?

SQLite (embedded, dev/small), PostgreSQL, and MySQL. Choose based on team size, durability, and availability requirements.

Software development & web development with DEV.co

Need help beyond evaluating semaphore? DEV.co is a software development agency offering software development services and web development for teams of every size. Our software developers and web developers build custom software, web applications, APIs, and open-source devops integrations — and maintain them long-term.

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