| 1 | package legatus |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "io" |
| 6 | "log/slog" |
| 7 | "sync" |
| 8 | ) |
| 9 | |
| 10 | // FlowCtx threads through the steps of one flow execution on one host. Its param |
| 11 | // bag is private to this execution, so steps pass data forward without locking |
| 12 | // (IV3). Cross-host data goes through Shared. |
| 13 | type FlowCtx struct { |
| 14 | ctx context.Context |
| 15 | host *Host |
| 16 | conn Conn |
| 17 | log *slog.Logger |
| 18 | dryRun bool |
| 19 | prompter Prompter |
| 20 | shared *SharedStore |
| 21 | params map[string]any |
| 22 | changed map[string]bool |
| 23 | out io.Writer |
| 24 | } |
| 25 | |
| 26 | // FlowCtxOption configures a FlowCtx. |
| 27 | type FlowCtxOption func(*FlowCtx) |
| 28 | |
| 29 | // WithFlowLogger sets the per-flow logger. |
| 30 | func WithFlowLogger(l *slog.Logger) FlowCtxOption { |
| 31 | return func(fc *FlowCtx) { |
| 32 | if l != nil { |
| 33 | fc.log = l |
| 34 | } |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | // WithFlowDryRun toggles dry-run. |
| 39 | func WithFlowDryRun(d bool) FlowCtxOption { return func(fc *FlowCtx) { fc.dryRun = d } } |
| 40 | |
| 41 | // WithFlowPrompter sets the prompter. |
| 42 | func WithFlowPrompter(p Prompter) FlowCtxOption { |
| 43 | return func(fc *FlowCtx) { |
| 44 | if p != nil { |
| 45 | fc.prompter = p |
| 46 | } |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | // WithFlowShared sets the cross-host shared store. |
| 51 | func WithFlowShared(s *SharedStore) FlowCtxOption { |
| 52 | return func(fc *FlowCtx) { |
| 53 | if s != nil { |
| 54 | fc.shared = s |
| 55 | } |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | // WithFlowOutput sets the human-facing output sink steps stream to (Out()). |
| 60 | func WithFlowOutput(w io.Writer) FlowCtxOption { |
| 61 | return func(fc *FlowCtx) { |
| 62 | if w != nil { |
| 63 | fc.out = w |
| 64 | } |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | // NewFlowCtx builds a FlowCtx. The Runner uses it; step tests use it directly. |
| 69 | func NewFlowCtx(ctx context.Context, h *Host, c Conn, opts ...FlowCtxOption) *FlowCtx { |
| 70 | fc := &FlowCtx{ |
| 71 | ctx: ctx, |
| 72 | host: h, |
| 73 | conn: c, |
| 74 | log: slog.Default(), |
| 75 | prompter: DenyPrompter{}, |
| 76 | shared: NewSharedStore(), |
| 77 | params: map[string]any{}, |
| 78 | changed: map[string]bool{}, |
| 79 | out: io.Discard, |
| 80 | } |
| 81 | for _, o := range opts { |
| 82 | o(fc) |
| 83 | } |
| 84 | return fc |
| 85 | } |
| 86 | |
| 87 | // Ctx returns the execution context. |
| 88 | func (fc *FlowCtx) Ctx() context.Context { return fc.ctx } |
| 89 | |
| 90 | // Host returns the target host. |
| 91 | func (fc *FlowCtx) Host() *Host { return fc.host } |
| 92 | |
| 93 | // Conn returns the live connection to the host. |
| 94 | func (fc *FlowCtx) Conn() Conn { return fc.conn } |
| 95 | |
| 96 | // Out returns the human-facing output sink. The engine owns it; steps stream |
| 97 | // command output here (never os.Stdout) when asked. Never nil — io.Discard by |
| 98 | // default, so an unconfigured Runner silently discards. |
| 99 | func (fc *FlowCtx) Out() io.Writer { return fc.out } |
| 100 | |
| 101 | // Log returns the per-flow logger, pre-tagged by the Runner with host and step. |
| 102 | func (fc *FlowCtx) Log() *slog.Logger { return fc.log } |
| 103 | |
| 104 | // DryRun reports whether this is a dry run. |
| 105 | func (fc *FlowCtx) DryRun() bool { return fc.dryRun } |
| 106 | |
| 107 | // Prompter returns the injected prompter (non-interactive by default). |
| 108 | func (fc *FlowCtx) Prompter() Prompter { return fc.prompter } |
| 109 | |
| 110 | // Shared returns the cross-host store. |
| 111 | func (fc *FlowCtx) Shared() *SharedStore { return fc.shared } |
| 112 | |
| 113 | // Set stores a value in the per-flow param bag. |
| 114 | func (fc *FlowCtx) Set(key string, v any) { fc.params[key] = v } |
| 115 | |
| 116 | // Get reads a value from the per-flow param bag. |
| 117 | func (fc *FlowCtx) Get(key string) (any, bool) { |
| 118 | v, ok := fc.params[key] |
| 119 | return v, ok |
| 120 | } |
| 121 | |
| 122 | // setChanged records, by step name, whether a step changed (or would change in |
| 123 | // dry-run). The runner calls it after each step resolves, before the next step's |
| 124 | // Check. Duplicate names OR-accumulate, so two same-named steps collapse to "any |
| 125 | // of them changed". |
| 126 | func (fc *FlowCtx) setChanged(name string, did bool) { |
| 127 | fc.changed[name] = fc.changed[name] || did |
| 128 | } |
| 129 | |
| 130 | // Changed reports whether the named earlier step changed (or would change in |
| 131 | // dry-run) during this flow execution on this host. An unrun or unrecorded step |
| 132 | // reports false. |
| 133 | func (fc *FlowCtx) Changed(name string) bool { return fc.changed[name] } |
| 134 | |
| 135 | // AnyChanged reports whether any of the named earlier steps changed. With no |
| 136 | // names, it reports whether any earlier step in this flow changed. Visibility is |
| 137 | // limited to steps already executed on this host (never cross-host). |
| 138 | func (fc *FlowCtx) AnyChanged(names ...string) bool { |
| 139 | if len(names) == 0 { |
| 140 | for _, v := range fc.changed { |
| 141 | if v { |
| 142 | return true |
| 143 | } |
| 144 | } |
| 145 | return false |
| 146 | } |
| 147 | for _, n := range names { |
| 148 | if fc.changed[n] { |
| 149 | return true |
| 150 | } |
| 151 | } |
| 152 | return false |
| 153 | } |
| 154 | |
| 155 | func (fc *FlowCtx) snapshot() map[string]any { |
| 156 | out := make(map[string]any, len(fc.params)) |
| 157 | for k, v := range fc.params { |
| 158 | out[k] = v |
| 159 | } |
| 160 | return out |
| 161 | } |
| 162 | |
| 163 | // Param reads a typed value from the per-flow param bag. |
| 164 | func Param[T any](fc *FlowCtx, key string) (T, bool) { |
| 165 | var zero T |
| 166 | v, ok := fc.params[key] |
| 167 | if !ok { |
| 168 | return zero, false |
| 169 | } |
| 170 | t, ok := v.(T) |
| 171 | return t, ok |
| 172 | } |
| 173 | |
| 174 | // SetParam stores a typed value in the per-flow param bag. |
| 175 | func SetParam[T any](fc *FlowCtx, key string, v T) { fc.params[key] = v } |
| 176 | |
| 177 | // SharedStore is the cross-host, concurrency-safe param store carried by a |
| 178 | // Runner. Per-host flows publish here for later flows (e.g. exits → relay). |
| 179 | type SharedStore struct { |
| 180 | mu sync.RWMutex |
| 181 | params map[string]any |
| 182 | } |
| 183 | |
| 184 | // NewSharedStore returns an empty store. |
| 185 | func NewSharedStore() *SharedStore { return &SharedStore{params: map[string]any{}} } |
| 186 | |
| 187 | // Set stores a value. |
| 188 | func (s *SharedStore) Set(key string, v any) { |
| 189 | s.mu.Lock() |
| 190 | defer s.mu.Unlock() |
| 191 | s.params[key] = v |
| 192 | } |
| 193 | |
| 194 | // Get reads a value. |
| 195 | func (s *SharedStore) Get(key string) (any, bool) { |
| 196 | s.mu.RLock() |
| 197 | defer s.mu.RUnlock() |
| 198 | v, ok := s.params[key] |
| 199 | return v, ok |
| 200 | } |
| 201 | |
| 202 | // SharedParam reads a typed value from a SharedStore. |
| 203 | func SharedParam[T any](s *SharedStore, key string) (T, bool) { |
| 204 | var zero T |
| 205 | s.mu.RLock() |
| 206 | defer s.mu.RUnlock() |
| 207 | v, ok := s.params[key] |
| 208 | if !ok { |
| 209 | return zero, false |
| 210 | } |
| 211 | t, ok := v.(T) |
| 212 | return t, ok |
| 213 | } |
| 214 | |
| 215 | // SetSharedParam stores a typed value in a SharedStore. |
| 216 | func SetSharedParam[T any](s *SharedStore, key string, v T) { |
| 217 | s.mu.Lock() |
| 218 | defer s.mu.Unlock() |
| 219 | s.params[key] = v |
| 220 | } |
| 221 | |