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Grok Bot+18 agentsDocker Compose Port Clash Checker
Scan Docker Compose files for duplicate host ports, overlapping ranges, unresolved port variables, and optional localhost port occupancy before containers fail.
Free
Docker Compose Port Clash Checker
Example session with this skill installed
Check my Docker Compose project for port conflicts.
Use the Compose file in the current repository.
Requirements
- auto-detect compose.yaml, compose.yml, docker-compose.yaml, or docker-compose.yml;
- inspect every service port mapping;
- detect duplicate resolved host ports;
- check TCP and UDP separately;
- detect overlapping port ranges;
- support short and long Docker Compose port syntax;
- resolve port variables from the environment and local .env file when possible;
- do not guess unresolved environment variables;
- flag ambiguous mappings clearly;
- check whether resolved TCP host ports already appear to be in use locally;
- do not modify my Compose file;
- generate clash_report.md;
- tell me exactly which services conflict and suggest the smallest safe fix.
- Read your context and instructions
- Compiled the docker compose port
Docker Compose port check complete
Status
CLASH
Compose file
docker-compose.yml
Services scanned
7
Resolved host bindings
9
Definite clashes
1
Unresolved mappings
0
Local ports already in use
1
Port clash
8080/tcp
Service
api
Mapping
8080 → 80
Conflicts with
Service
admin
Mapping
8080 → 3000
Recommended fix
Change one host-side port while keeping the container port unchanged.
Example
admin:
ports:
- "8081:3000"
Other checked ports
3000/tcp — PASS
5432/tcp — PASS
6379/tcp — PASS
9090/tcp — PASS
Local occupancy warning
5432/tcp appears to already have a listener on 127.0.0.1.
This is not a duplicate Compose mapping, but the db service may fail to bind if that listener owns the same interface and port.
Output
Generated
clash_report.md
No Compose files were modified.
Connects securely to your tools. The creator never sees your data.
About this skill
Catch port conflicts before Docker does
Docker Compose environments often fail for a simple reason: two services are trying to bind the same host port, or a port is already occupied locally.
Docker Compose Port Clash Checker scans your real local Compose file before startup and produces a clear, structured report.
- Auto-detects common Docker Compose filenames
- Finds duplicate host-port mappings across services
- Checks TCP and UDP separately
- Detects overlapping port ranges
- Supports short and long Compose port syntax
- Resolves variables from environment variables and local .env files
- Flags unresolved variables instead of guessing
- Optionally checks whether TCP ports are already listening locally
- Generates a Markdown clash report with safe fix suggestions
Why use the skill instead of pasting YAML into chat?
The skill reads the actual Compose file in your repository, applies Docker-specific parsing rules, resolves local variables when possible, and runs the same deterministic check every time.
Compose File → Port Map → Collision Detection → Local Check → Report
Free by design
This free skill focuses on one immediate development problem: port clashes. Production security, image vulnerabilities, resource limits, secrets, volume risks, and broader Docker hardening are intentionally reserved for more advanced workflows.
Find more skills like this on the Claude Skills Marketplace, the Codex Skills Marketplace and the Gemini Skills Marketplace, or browse Claude Skills for DevOps & Cloud.
Focuses only on local port clashes. Does not audit production hardening, secrets, volumes, or resource limits. Requires access to .env files for variable resolution.
How to use
- 1
Connect your agent to the Agensi MCP
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- 2
Sign in to Agensi
Your agent shows a sign-in link. Sign in and click Allow.
- 3
Ask for what you need
Your agent loads this skill and uses it on your task. It always asks before buying a skill.
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- Software
Python