Pierre-Olivier Mercier
77dfb82313
Hosts that register the provider only for its definition (externalizable checker) construct it with a nil CollectFn. If the local ObservationContext ends up calling Collect, the previous code dereferenced a nil function value and crashed the goroutine. Surface a typed error so rules degrade to a clean StatusError state.
40 lines
1.3 KiB
Go
40 lines
1.3 KiB
Go
// SPDX-License-Identifier: MIT
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package checker
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import (
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"context"
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"errors"
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sdk "git.happydns.org/checker-sdk-go/checker"
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)
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// ErrNoCollector is returned by Collect when the provider was constructed
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// without a CollectFn (e.g. when registered host-side as an externalizable-only
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// provider). Callers should route the observation to an external checker.
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var ErrNoCollector = errors.New("dnsviz: provider has no local collector; use an external checker")
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// CollectFn is the function signature for the DNSViz data collection step.
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// The checker package is decoupled from the subprocess invocation so it can
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// be imported without GPL obligations. Implementations live in the binary or
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// plugin layer (see internal/collect).
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type CollectFn func(ctx context.Context, opts sdk.CheckerOptions) (any, error)
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// Provider returns a new DNSViz observation provider backed by the given
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// collect function.
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func Provider(collect CollectFn) sdk.ObservationProvider {
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return &dnsvizProvider{collect: collect}
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}
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type dnsvizProvider struct{ collect CollectFn }
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func (p *dnsvizProvider) Key() sdk.ObservationKey {
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return ObservationKeyDNSViz
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}
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func (p *dnsvizProvider) Collect(ctx context.Context, opts sdk.CheckerOptions) (any, error) {
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if p.collect == nil {
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return nil, ErrNoCollector
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}
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return p.collect(ctx, opts)
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}
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