diff --git a/checker/context.go b/checker/context.go new file mode 100644 index 0000000..9dd8918 --- /dev/null +++ b/checker/context.go @@ -0,0 +1,52 @@ +// Copyright 2020-2026 The happyDomain Authors +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package checker + +import "context" + +type enabledRulesCtxKey struct{} + +// WithEnabledRules returns a context carrying the host's per-rule enable map. +// The SDK server attaches it before calling ObservationProvider.Collect so +// providers can skip optional work (network calls, paid API hits, …) for +// rules the host has disabled. A nil map means "run everything". +func WithEnabledRules(ctx context.Context, enabled map[string]bool) context.Context { + if enabled == nil { + return ctx + } + return context.WithValue(ctx, enabledRulesCtxKey{}, enabled) +} + +// EnabledRulesFromContext returns the enabled-rule map attached by +// WithEnabledRules, or nil if none. RuleEnabled is the usual access pattern. +func EnabledRulesFromContext(ctx context.Context) map[string]bool { + m, _ := ctx.Value(enabledRulesCtxKey{}).(map[string]bool) + return m +} + +// RuleEnabled reports whether ruleName is enabled given the host's map. +// Absent rules default to enabled (nil map or rule not in map), matching +// the SDK server's evaluate-side semantics. +func RuleEnabled(ctx context.Context, ruleName string) bool { + m := EnabledRulesFromContext(ctx) + if m == nil { + return true + } + enabled, ok := m[ruleName] + if !ok { + return true + } + return enabled +} diff --git a/checker/names.go b/checker/names.go new file mode 100644 index 0000000..61df52e --- /dev/null +++ b/checker/names.go @@ -0,0 +1,37 @@ +// Copyright 2020-2026 The happyDomain Authors +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package checker + +import "strings" + +// JoinRelative treats name as relative to origin, as happyDomain encodes +// service-embedded record owners and subdomains. An empty or "@" name +// resolves to the origin itself; an empty origin returns the trimmed name +// unchanged. A name already suffixed by origin is returned as-is so that +// absolute encodings round-trip safely. Trailing dots are stripped. +func JoinRelative(name, origin string) string { + origin = strings.TrimSuffix(origin, ".") + name = strings.TrimSuffix(name, ".") + if origin == "" { + return name + } + if name == "" || name == "@" { + return origin + } + if name == origin || strings.HasSuffix(name, "."+origin) { + return name + } + return name + "." + origin +} diff --git a/checker/server/server.go b/checker/server/server.go index 763a600..c6c43f2 100644 --- a/checker/server/server.go +++ b/checker/server/server.go @@ -133,6 +133,7 @@ func New(provider checker.ObservationProvider) *Server { s.definition = def s.definition.BuildRulesInfo() s.mux.HandleFunc("GET /definition", s.handleDefinition) + s.mux.Handle("POST /definition", s.TrackWork(http.HandlerFunc(s.handlePrecheck))) s.mux.Handle("POST /evaluate", s.TrackWork(http.HandlerFunc(s.handleEvaluate))) } } @@ -316,6 +317,51 @@ func (s *Server) handleDefinition(w http.ResponseWriter, r *http.Request) { writeJSON(w, http.StatusOK, s.definition) } +// handlePrecheck answers POST /definition: it returns the same +// definition body as GET /definition, plus a PrecheckFailures map +// listing rules whose prerequisites are unmet for the submitted +// options. Rules that do not implement checker.RulePrecheck, or whose +// Precheck returned nil, are omitted from that map. +func (s *Server) handlePrecheck(w http.ResponseWriter, r *http.Request) { + var req checker.RulePrecheckRequest + if r.ContentLength != 0 { + if err := json.NewDecoder(io.LimitReader(r.Body, maxRequestBodySize)).Decode(&req); err != nil { + writeJSON(w, http.StatusBadRequest, map[string]string{ + "error": fmt.Sprintf("invalid request body: %v", err), + }) + return + } + } + + failures := map[string]string{} + for _, rule := range s.definition.Rules { + pc, ok := rule.(checker.RulePrecheck) + if !ok { + continue + } + if err := pc.Precheck(r.Context(), req.Options); err != nil { + failures[rule.Name()] = err.Error() + } + } + resp := checker.RulePrecheckResponse{ + CheckerDefinition: s.definition, + PrecheckFailures: failures, + } + if en, ok := s.provider.(checker.CheckEnabler); ok { + eligible, reason, err := en.IsEligible(r.Context(), req.Options) + if err != nil { + // Eligibility undetermined: leave Eligible nil so the host fails + // open (shows the checker), but surface the error for diagnostics. + log.Printf("IsEligible failed: %v", err) + resp.EligibilityReason = err.Error() + } else { + resp.Eligible = &eligible + resp.EligibilityReason = reason + } + } + writeJSON(w, http.StatusOK, resp) +} + func (s *Server) handleCollect(w http.ResponseWriter, r *http.Request) { var req checker.ExternalCollectRequest if err := json.NewDecoder(io.LimitReader(r.Body, maxRequestBodySize)).Decode(&req); err != nil { @@ -325,7 +371,8 @@ func (s *Server) handleCollect(w http.ResponseWriter, r *http.Request) { return } - data, err := s.provider.Collect(r.Context(), req.Options) + ctx := checker.WithEnabledRules(r.Context(), req.EnabledRules) + data, err := s.provider.Collect(ctx, req.Options) if err != nil { writeJSON(w, http.StatusInternalServerError, checker.ExternalCollectResponse{ Error: err.Error(), diff --git a/checker/server/server_test.go b/checker/server/server_test.go index 9e0adc4..d6feefa 100644 --- a/checker/server/server_test.go +++ b/checker/server/server_test.go @@ -667,3 +667,196 @@ func TestServer_NoDefinition_NoEvaluateEndpoint(t *testing.T) { t.Error("POST /evaluate should not be available without CheckerDefinitionProvider") } } + +// prereqRule implements RulePrecheck, failing when a named option is empty. +type prereqRule struct { + name string + optKey string + msg string +} + +func (r *prereqRule) Name() string { return r.name } +func (r *prereqRule) Description() string { return "" } +func (r *prereqRule) Evaluate(ctx context.Context, obs checker.ObservationGetter, opts checker.CheckerOptions) []checker.CheckState { + return []checker.CheckState{{Status: checker.StatusOK}} +} +func (r *prereqRule) Precheck(ctx context.Context, opts checker.CheckerOptions) error { + if v, _ := opts[r.optKey].(string); v == "" { + return errors.New(r.msg) + } + return nil +} + +// enablerProvider is a minimal ObservationProvider + CheckerDefinitionProvider +// that also implements CheckEnabler, returning whatever isEligibleFn yields. +type enablerProvider struct { + key checker.ObservationKey + definition *checker.CheckerDefinition + isEligibleFn func(ctx context.Context, opts checker.CheckerOptions) (bool, string, error) +} + +func (p *enablerProvider) Key() checker.ObservationKey { return p.key } +func (p *enablerProvider) Collect(ctx context.Context, opts checker.CheckerOptions) (any, error) { + return map[string]string{"result": "ok"}, nil +} +func (p *enablerProvider) Definition() *checker.CheckerDefinition { return p.definition } +func (p *enablerProvider) IsEligible(ctx context.Context, opts checker.CheckerOptions) (bool, string, error) { + return p.isEligibleFn(ctx, opts) +} + +func TestServer_Precheck_Eligibility(t *testing.T) { + tests := []struct { + name string + fn func(ctx context.Context, opts checker.CheckerOptions) (bool, string, error) + wantNil bool // expect Eligible == nil + wantElig bool // value of *Eligible when not nil + wantReason string // expected EligibilityReason + }{ + { + name: "eligible true", + fn: func(context.Context, checker.CheckerOptions) (bool, string, error) { return true, "", nil }, + wantElig: true, + }, + { + name: "eligible false with reason", + fn: func(context.Context, checker.CheckerOptions) (bool, string, error) { return false, "not a reverse zone", nil }, + wantElig: false, + wantReason: "not a reverse zone", + }, + { + name: "error fails open", + fn: func(context.Context, checker.CheckerOptions) (bool, string, error) { return false, "", errors.New("lookup timeout") }, + wantNil: true, + wantReason: "lookup timeout", + }, + } + + for _, tc := range tests { + t.Run(tc.name, func(t *testing.T) { + p := &enablerProvider{ + key: "test", + definition: &checker.CheckerDefinition{ID: "test", Rules: []checker.CheckRule{}}, + isEligibleFn: tc.fn, + } + srv := New(p) + defer srv.Close() + + rec := doRequest(srv.Handler(), "POST", "/definition", checker.RulePrecheckRequest{Options: checker.CheckerOptions{}}, nil) + if rec.Code != http.StatusOK { + t.Fatalf("POST /definition = %d, want %d", rec.Code, http.StatusOK) + } + var resp checker.RulePrecheckResponse + if err := json.NewDecoder(rec.Body).Decode(&resp); err != nil { + t.Fatalf("decode: %v", err) + } + if tc.wantNil { + if resp.Eligible != nil { + t.Errorf("Eligible = %v, want nil", *resp.Eligible) + } + } else { + if resp.Eligible == nil { + t.Fatalf("Eligible = nil, want %v", tc.wantElig) + } + if *resp.Eligible != tc.wantElig { + t.Errorf("Eligible = %v, want %v", *resp.Eligible, tc.wantElig) + } + } + if resp.EligibilityReason != tc.wantReason { + t.Errorf("EligibilityReason = %q, want %q", resp.EligibilityReason, tc.wantReason) + } + }) + } +} + +// TestServer_Precheck_NoEnabler verifies that a provider not implementing +// CheckEnabler yields no eligibility fields (Eligible nil, reason empty). +func TestServer_Precheck_NoEnabler(t *testing.T) { + p := &testProvider{key: "test", definition: &checker.CheckerDefinition{ID: "test", Rules: []checker.CheckRule{}}} + srv := newTestServer(p) + defer srv.Close() + + rec := doRequest(srv.Handler(), "POST", "/definition", checker.RulePrecheckRequest{Options: checker.CheckerOptions{}}, nil) + if rec.Code != http.StatusOK { + t.Fatalf("POST /definition = %d, want %d", rec.Code, http.StatusOK) + } + if bytes.Contains(rec.Body.Bytes(), []byte("eligible")) { + t.Errorf("response leaked eligible field for non-enabler provider: %s", rec.Body.String()) + } + var resp checker.RulePrecheckResponse + if err := json.NewDecoder(rec.Body).Decode(&resp); err != nil { + t.Fatalf("decode: %v", err) + } + if resp.Eligible != nil { + t.Errorf("Eligible = %v, want nil for non-enabler provider", *resp.Eligible) + } +} + +func TestServer_Precheck(t *testing.T) { + gated := &prereqRule{name: "gated", optKey: "api_key", msg: "missing API key"} + open := &dummyRule{name: "open", desc: "no prereq"} + p := &testProvider{ + key: "test", + definition: &checker.CheckerDefinition{ + ID: "test", + Rules: []checker.CheckRule{gated, open}, + }, + } + srv := newTestServer(p) + defer srv.Close() + handler := srv.Handler() + + // GET /definition stays static — no precheck information surfaces here. + rec := doRequest(handler, "GET", "/definition", nil, nil) + if rec.Code != http.StatusOK { + t.Fatalf("GET /definition = %d, want %d", rec.Code, http.StatusOK) + } + if bytes.Contains(rec.Body.Bytes(), []byte("precheck_failures")) { + t.Errorf("GET /definition leaked precheck_failures field: %s", rec.Body.String()) + } + + // POST /definition with empty opts: gated rule fails, open rule absent. + rec = doRequest(handler, "POST", "/definition", checker.RulePrecheckRequest{Options: checker.CheckerOptions{}}, nil) + if rec.Code != http.StatusOK { + t.Fatalf("POST /definition (empty opts) = %d, want %d", rec.Code, http.StatusOK) + } + var resp checker.RulePrecheckResponse + if err := json.NewDecoder(rec.Body).Decode(&resp); err != nil { + t.Fatalf("decode POST /definition: %v", err) + } + if resp.CheckerDefinition == nil { + t.Fatalf("POST /definition response missing embedded CheckerDefinition") + } + if resp.ID != "test" { + t.Errorf("response ID = %q, want %q", resp.ID, "test") + } + if len(resp.RulesInfo) != 2 { + t.Errorf("response RulesInfo len = %d, want 2", len(resp.RulesInfo)) + } + if got := resp.PrecheckFailures["gated"]; got != "missing API key" { + t.Errorf("PrecheckFailures[gated] = %q, want %q", got, "missing API key") + } + if _, ok := resp.PrecheckFailures["open"]; ok { + t.Errorf("PrecheckFailures[open] should be absent (no RulePrecheck impl), got %q", resp.PrecheckFailures["open"]) + } + if len(resp.PrecheckFailures) != 1 { + t.Errorf("PrecheckFailures = %v, want exactly 1 entry", resp.PrecheckFailures) + } + + // POST /definition with sufficient opts: empty failure map. + rec = doRequest(handler, "POST", "/definition", checker.RulePrecheckRequest{ + Options: checker.CheckerOptions{"api_key": "secret"}, + }, nil) + if rec.Code != http.StatusOK { + t.Fatalf("POST /definition (with opts) = %d, want %d", rec.Code, http.StatusOK) + } + resp = checker.RulePrecheckResponse{} + if err := json.NewDecoder(rec.Body).Decode(&resp); err != nil { + t.Fatalf("decode POST /definition: %v", err) + } + if resp.CheckerDefinition == nil || resp.ID != "test" { + t.Errorf("response missing definition: %+v", resp) + } + if len(resp.PrecheckFailures) != 0 { + t.Errorf("PrecheckFailures = %v, want empty when opts satisfy prereqs", resp.PrecheckFailures) + } +} diff --git a/checker/types.go b/checker/types.go index 7256766..ed4a9fc 100644 --- a/checker/types.go +++ b/checker/types.go @@ -250,6 +250,71 @@ type CheckRuleWithOptions interface { Options() CheckerOptionsDocumentation } +// RulePrecheck is an optional interface a CheckRule can implement to +// declare whether the current options are sufficient for the rule to +// run. Return nil if runnable, or an error describing the missing +// prerequisite (for example "missing API key"). The host calls this via +// POST /definition to surface unavailable rules in the UI; it is never +// invoked from Collect, so rules that need to short-circuit at run time +// must keep their own self-guard. +type RulePrecheck interface { + CheckRule + Precheck(ctx context.Context, opts CheckerOptions) error +} + +// CheckEnabler is an optional interface an ObservationProvider can implement +// to declare, from the actual target data, whether running this checker is +// meaningful at all. +// +// It complements the two existing gates: +// - CheckerAvailability is a static, registration-time scope/service-type +// filter; it never sees the target's data. +// - RulePrecheck is a per-rule, options-only check ("missing API key"). +// +// CheckEnabler is whole-checker and data-driven. IsEligible receives the same +// CheckerOptions as Collect, including the autofilled domain_name / zone / +// service payloads (read them with GetOption), and may perform light I/O +// (e.g. a DNSKEY lookup) to decide. +// +// Return (true, "", nil) to run the checker, or (false, reason, nil) with a +// short human-readable reason ("not a reverse zone", "DNSSEC not enabled") +// to skip it. Return a non-nil error only when eligibility could not be +// determined (transient I/O failure); the host treats that as "unknown" and +// fails open (shows the checker) rather than as a definitive skip. +// +// Detect support with a type assertion: _, ok := provider.(CheckEnabler) +type CheckEnabler interface { + IsEligible(ctx context.Context, opts CheckerOptions) (eligible bool, reason string, err error) +} + +// RulePrecheckRequest is the body accepted by POST /definition. +type RulePrecheckRequest struct { + Options CheckerOptions `json:"options"` +} + +// RulePrecheckResponse is the body returned by POST /definition. The +// embedded *CheckerDefinition mirrors GET /definition so a client can +// fetch the full definition and precheck results in one round-trip. +// Keys in PrecheckFailures are rule names; values are the precheck +// error messages. Rules that do not implement RulePrecheck, or whose +// Precheck returned nil for the given options, are absent from the map. +type RulePrecheckResponse struct { + *CheckerDefinition + PrecheckFailures map[string]string `json:"precheck_failures"` + + // Eligible reports whether this checker is meaningful for the submitted + // target, as decided by the provider's CheckEnabler (if implemented). It + // is nil when the checker does not implement CheckEnabler, or when + // IsEligible could not determine eligibility (its error was non-nil). A + // non-nil false means the checker is definitively not applicable to this + // target; the host should hide it unless Eligible != nil && !*Eligible. + Eligible *bool `json:"eligible,omitempty"` + + // EligibilityReason explains a false Eligible, or carries the lookup error + // message when eligibility could not be determined. Empty otherwise. + EligibilityReason string `json:"eligibility_reason,omitempty"` +} + // ObservationGetter provides access to observation data (used by CheckRule). // Get unmarshals observation data into dest (like json.Unmarshal). // @@ -421,10 +486,17 @@ type OptionsValidator interface { } // ExternalCollectRequest is sent to POST /collect on a remote checker endpoint. +// +// EnabledRules lets the host inform the provider which rules will be evaluated +// downstream, so the provider can skip optional work (network calls, paid API +// hits, …) for data that would not surface in any state. nil means "run +// everything"; an explicit map with a rule name set to false means that rule +// is off. Providers access the value via EnabledRulesFromContext(ctx). type ExternalCollectRequest struct { - Key ObservationKey `json:"key"` - Target CheckTarget `json:"target"` - Options CheckerOptions `json:"options"` + Key ObservationKey `json:"key"` + Target CheckTarget `json:"target"` + Options CheckerOptions `json:"options"` + EnabledRules map[string]bool `json:"enabledRules,omitempty"` } // ExternalCollectResponse is returned by POST /collect on a remote checker endpoint.