nurse/protocols/redis/ping.go

88 lines
1.8 KiB
Go

package redis
import (
"context"
"fmt"
"github.com/go-redis/redis/v8"
"code.1533b4dc0.de/prskr/nurse/check"
"code.1533b4dc0.de/prskr/nurse/config"
"code.1533b4dc0.de/prskr/nurse/grammar"
"code.1533b4dc0.de/prskr/nurse/validation"
)
var _ check.SystemChecker = (*PingCheck)(nil)
type PingCheck struct {
redis.UniversalClient
validators validation.Validator[redis.Cmder]
Message string
}
func (p PingCheck) Execute(ctx check.Context) error {
if p.Message == "" {
return p.Ping(ctx).Err()
}
for {
select {
case <-ctx.Done():
return ctx.Err()
default:
attemptCtx, cancel := ctx.AttemptContext()
err := p.executeAttempt(attemptCtx)
cancel()
if err == nil {
return nil
}
}
}
}
func (p PingCheck) executeAttempt(ctx context.Context) error {
if resp, err := p.Do(ctx, "PING", p.Message).Text(); err != nil {
return err
} else if resp != p.Message {
return fmt.Errorf("expected value %s got %s", p.Message, resp)
}
return nil
}
func (p *PingCheck) UnmarshalCheck(c grammar.Check, lookup config.ServerLookup) error {
const (
serverOnlyArgCount = 1
serverAndMessageArgCount = 2
)
val, _ := GenericCommandValidatorFor("PONG")
validators := validation.Chain[redis.Cmder]{}
validators = append(validators, val)
p.validators = validators
init := c.Initiator
switch len(init.Params) {
case 0:
return grammar.ErrMissingServer
case serverAndMessageArgCount:
if msg, err := init.Params[1].AsString(); err != nil {
return err
} else {
val, _ := GenericCommandValidatorFor(msg)
p.validators = validation.Chain[redis.Cmder]{val}
}
fallthrough
case serverOnlyArgCount:
if cli, err := clientFromParam(init.Params[0], lookup); err != nil {
return err
} else {
p.UniversalClient = cli
}
return nil
default:
return grammar.ErrAmbiguousParamCount
}
}