ClickHouse Pydantic Config
<!-- ADR: 2025-12-09-clickhouse-pydantic-config-skill -->Generate DBeaver database client configurations from Pydantic v2 models using mise [env] as Single Source of Truth (SSoT).
Critical Design Principle: Semi-Prescriptive Adaptation
This skill is NOT a rigid template. It provides a SSoT pattern that MUST be adapted to each repository's structure and local database situation.
Why This Matters
Each repository has unique:
- •Directory layouts (
.dbeaver/location may vary) - •Environment variable naming conventions
- •Existing connection management patterns
- •Local vs cloud database mix
The SSoT principle is the constant; the implementation details are the variables.
Quick Start
# Generate local connection config mise run db-client-generate # Generate cloud connection config mise run db-client:cloud # Preview without writing mise run db-client:dry-run # Launch DBeaver mise run dbeaver
Credential Prerequisites (Cloud Mode)
<!-- ADR: 2025-12-10-clickhouse-skill-documentation-gaps -->Before using cloud mode, obtain credentials via the skill chain:
- •Create/retrieve user: Use
clickhouse-cloud-managementskill to create read-only users or retrieve existing credentials from 1Password - •Store in .env: Add to
.envfile (gitignored):
CLICKHOUSE_USER_READONLY=your_user CLICKHOUSE_PASSWORD_READONLY=your_password
- •Generate config: Run
mise run db-client:cloud
Skill chain: clickhouse-cloud-management → .env → clickhouse-pydantic-config
mise [env] as Single Source of Truth
All configurable values live in .mise.toml:
[env] CLICKHOUSE_NAME = "clickhouse-local" CLICKHOUSE_MODE = "local" # "local" or "cloud" CLICKHOUSE_HOST = "localhost" CLICKHOUSE_PORT = "8123" CLICKHOUSE_DATABASE = "default"
Scripts read from os.environ.get() with backward-compatible defaults—works with or without mise installed.
Credential Handling by Mode
| Mode | Approach | Rationale |
|---|---|---|
| Local | Hardcode default user, empty password | Zero friction, no security concern |
| Cloud | Pre-populate from .env | Read from environment, write to gitignored JSON |
Key principle: The generated data-sources.json is gitignored anyway. Pre-populating credentials trades zero security risk for maximum developer convenience.
Cloud Credentials Setup
# .env (gitignored) CLICKHOUSE_USER_READONLY=readonly_user CLICKHOUSE_PASSWORD_READONLY=your-secret-password
Repository Adaptation Workflow
Pre-Implementation Discovery (Phase 0)
Before writing any code, the executor MUST:
# 1. Discover existing configuration patterns fd -t f ".mise.toml" . fd -t f ".env*" . fd -t d ".dbeaver" . # 2. Test ClickHouse connectivity (local) clickhouse-client --host localhost --port 9000 --query "SELECT 1" # 3. Check for existing connection configs fd -t f "data-sources.json" . fd -t f "dataSources.xml" .
Adaptation Decision Matrix
| Discovery Finding | Adaptation Action |
|---|---|
Existing .mise.toml at repo root | Extend existing [env] section, don't create new file |
Existing .dbeaver/ directory | Merge connections, preserve existing entries |
| Non-standard CLICKHOUSE_* vars | Map to repository's naming convention |
| Multiple databases (local + cloud) | Generate multiple connection entries |
| No ClickHouse available | Warn and generate placeholder config |
Validation Checklist (Post-Generation)
The executor MUST verify:
- • Generated JSON is valid (
jq . .dbeaver/data-sources.json) - • DBeaver can import the config (launch and verify connection appears)
- • mise tasks execute without error (
mise run db-client-generate) - •
.dbeaver/added to.gitignore
Pydantic Model
The ClickHouseConnection model provides:
- •Type-safe configuration with Pydantic v2 validation
- •Computed fields for JDBC URL and connection ID
- •Mode-aware defaults (cloud auto-enables SSL on port 8443)
- •Environment loading via
from_env()class method
See references/pydantic-model.md for complete model documentation.
DBeaver Format
DBeaver uses .dbeaver/data-sources.json with this structure:
{
"folders": {},
"connections": {
"clickhouse-jdbc-{random-hex}": {
"provider": "clickhouse",
"driver": "com_clickhouse",
"name": "Connection Name",
"configuration": { ... }
}
}
}
Important: DBeaver does NOT support ${VAR} substitution—values must be pre-populated at generation time.
See references/dbeaver-format.md for complete format specification.
macOS Notes
- •DBeaver binary: Use
/Applications/DBeaver.app/Contents/MacOS/dbeaver(NOTopen -a) - •Gitignore: Add
.dbeaver/to.gitignore
Related Skills
| Skill | Integration |
|---|---|
devops-tools:clickhouse-cloud-management | Credential retrieval for cloud mode |
quality-tools:clickhouse-architect | Schema design context |
itp:mise-configuration | SSoT environment variable patterns |
Python Driver Policy
For Python application code connecting to ClickHouse (not DBeaver), use clickhouse-connect (official HTTP driver). See clickhouse-architect for:
- •Recommended code patterns
- •Why NOT to use
clickhouse-driver(community) - •Performance vs maintenance trade-offs
Additional Resources
| Reference | Content |
|---|---|
| references/pydantic-model.md | Complete model documentation |
| references/dbeaver-format.md | DBeaver JSON format spec |