63 lines
1.7 KiB
Markdown
63 lines
1.7 KiB
Markdown
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# Platform Constraints
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Validation rules and predicates for configuration values.
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## Constraint Files
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### Common (`common.ncl`)
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General validation rules applicable to all services:
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**Port constraints:**
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- `valid_port(port)` - Check if port is in valid range (1024-65535)
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**String enumeration constraints:**
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- `valid_log_level(level)` - Check against valid log levels
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- `valid_auth_method(method)` - Check against valid auth methods
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- `valid_storage_backend(backend)` - Check against valid backends
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- `valid_deployment_mode(mode)` - Check against deployment modes
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- `valid_llm_provider(provider)` - Check against LLM providers
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**Numeric constraints:**
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- `valid_budget_threshold(percent)` - Check percentage is 0-100
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- `valid_worker_count(count)` - Check worker count is in range
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- `valid_connection_count(count)` - Check connection count is valid
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**URL constraints:**
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- `valid_url(url)` - Check URL has valid protocol scheme
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## Usage Pattern
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```nickel
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let constraints = import "constraints/common.ncl" in
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# Validate port
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assert constraints.valid_port 8080
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# Validate enum
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assert constraints.valid_log_level "debug"
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# In a record definition (using Nickel contracts)
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{
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port | Number | doc "Server port" | {
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predicate = fun p => constraints.valid_port p,
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label = "valid port range"
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} = 8080
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}
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```
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## Constraint Philosophy
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Constraints are **predicates** - functions that return true/false for validation:
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- Used in Nickel's contract system: `field | Type | {predicate = constraint_fn}`
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- Enable **gradual validation** - catch errors at config generation time
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- Prevent invalid configurations reaching runtime
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- Document valid value ranges inline
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## References
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- Parent: `../README.md`
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- Validators: `../validators/README.md`
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- Values: `../values/README.md`
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