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https://github.com/lukaszraczylo/graphql-monitoring-proxy.git
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lukaszraczylo
7e0d1e19b1
Starting with ENABLE_CIRCUIT_BREAKER=true panicked at boot: parseConfig -> initCircuitBreaker registers a metrics gauge, but cfg.Monitoring is assigned later by StartMonitoringServer, so the registration dereferenced a nil *MetricsSetup. Add nil-receiver guards to the MetricsSetup registration methods (RegisterMetricsGauge/GaugeFunc/Counter, RegisterFloatCounter, RegisterMetricsSummary/Histogram), matching their existing 'return a dummy to prevent panics' contract. The guard is a no-op for non-nil receivers, so existing callers are unaffected. The breaker and the admin dashboard (which reads gobreaker state directly) keep working. Add regression tests for the nil-receiver methods and for initCircuitBreaker with nil monitoring.
45 lines
1.5 KiB
Go
45 lines
1.5 KiB
Go
package main
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import (
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"bytes"
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"testing"
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libpack_logger "github.com/lukaszraczylo/graphql-monitoring-proxy/logging"
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"github.com/stretchr/testify/require"
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)
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// TestInitCircuitBreaker_NilMonitoring_NoPanic is a regression test for a boot
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// panic: enabling the circuit breaker (ENABLE_CIRCUIT_BREAKER=true) crashed at
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// startup because parseConfig calls initCircuitBreaker before the monitoring
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// server assigns cfg.Monitoring (StartMonitoringServer runs later). The metrics
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// gauge registration then dereferenced a nil *MetricsSetup.
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//
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// The breaker (and the admin dashboard, which reads gobreaker state directly)
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// must initialise without panicking even when monitoring is not yet available.
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func TestInitCircuitBreaker_NilMonitoring_NoPanic(t *testing.T) {
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origCfg := cfg
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cbMutex.Lock()
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origCb, origMetrics := cb, cbMetrics
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cb, cbMetrics = nil, nil
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cbMutex.Unlock()
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t.Cleanup(func() {
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cbMutex.Lock()
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cb, cbMetrics = origCb, origMetrics
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cbMutex.Unlock()
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cfg = origCfg
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})
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cfg = &config{}
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cfg.Logger = libpack_logger.New().SetOutput(&bytes.Buffer{})
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cfg.Monitoring = nil // the production state when parseConfig runs
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cfg.CircuitBreaker.Enable = true
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cfg.CircuitBreaker.MaxFailures = 3
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cfg.CircuitBreaker.Timeout = 5
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cfg.CircuitBreaker.MaxRequestsInHalfOpen = 2
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require.NotPanics(t, func() { initCircuitBreaker(cfg) },
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"initCircuitBreaker must not panic when cfg.Monitoring is nil")
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require.NotNil(t, cb, "circuit breaker must initialise even without monitoring")
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require.NotNil(t, cbMetrics, "circuit breaker metrics manager must be created")
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}
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