go.bigb.es/auxilia

v0.3.0
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Index

Variables

var ErrNoPrompter = culpa.WithCode(culpa.New("legatus: no interactive prompter configured"), "LEGATUS_NO_PROMPTER")

ErrNoPrompter is returned by the non-interactive default prompter when a step requires a choice it cannot answer.

Functions

f func Param

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func Param[T any](fc *FlowCtx, key string) (T, bool)

Param reads a typed value from the per-flow param bag.

f func SetParam

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func SetParam[T any](fc *FlowCtx, key string, v T)

SetParam stores a typed value in the per-flow param bag.

f func SetSharedParam

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func SetSharedParam[T any](s *SharedStore, key string, v T)

SetSharedParam stores a typed value in a SharedStore.

f func SharedParam

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func SharedParam[T any](s *SharedStore, key string) (T, bool)

SharedParam reads a typed value from a SharedStore.

Types

T type AlwaysApply

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type AlwaysApply struct{}

AlwaysApply embeds into steps with no meaningful check; Check always reports a change is needed.

m func (AlwaysApply) Check

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func (AlwaysApply) Check(*FlowCtx) (bool, error)

Check always reports need=true.

T type Cmd

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type Cmd struct {
	Path  string
	Args  []string
	Env   map[string]string
	Sudo  bool
	Stdin io.Reader
}

Cmd is a remote command. Args are passed structurally: a transport must quote each element so the remote shell can never re-split or re-evaluate it.

T type Conn

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type Conn interface {
	// Exec runs cmd to completion. A command that runs is not an error even on a
	// non-zero exit: the status is reported via ExecResult.ExitCode and err is
	// nil. err is reserved for failures to run the command at all (no session,
	// IO error, context cancellation). Callers decide whether a non-zero exit is
	// a failure (a step's Apply) or a signal (a probe like `test -e`).
	Exec(ctx context.Context, cmd Cmd) (ExecResult, error)
	// ExecStream runs cmd like Exec but streams output: a non-nil stdout/stderr
	// writer receives that stream live and the matching ExecResult field is left
	// nil; a nil writer buffers that stream into ExecResult exactly as Exec does,
	// so a caller can stream one stream while capturing the other. The exit-code
	// contract is identical to Exec — a clean run with a non-zero exit returns
	// err==nil with ExecResult.ExitCode set; ctx cancellation tears down the
	// process and returns ctx.Err() with bytes-so-far already written to the sink.
	ExecStream(ctx context.Context, cmd Cmd, stdout, stderr io.Writer) (ExecResult, error)
	Put(ctx context.Context, content io.Reader, remote string, mode FileMode, opts ...PutOption) error
	Get(ctx context.Context, remote string, w io.Writer) error
	Close() error
}

Conn is a live connection to one host. Transports implement it; the core engine depends only on this interface and never imports SSH (IV1, PC1).

T type DenyPrompter

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type DenyPrompter struct{}

DenyPrompter is the non-interactive default: it declines confirmations and errors on selections.

m func (DenyPrompter) Confirm

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func (DenyPrompter) Confirm(context.Context, string) (bool, error)

m func (DenyPrompter) Select

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func (DenyPrompter) Select(context.Context, string, []string) (int, error)

T type Dialer

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type Dialer interface {
	Dial(ctx context.Context, h *Host) (Conn, error)
}

Dialer opens a Conn to a host. transport provides the SSH implementation.

T type ErrorPolicy

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type ErrorPolicy int

ErrorPolicy governs cross-host behavior. Within a single host's flow a failed step always stops that flow (IV7); ErrorPolicy decides what happens to the other hosts. 

const (
	// ContinueOnError runs every host and collects all failures (default).
	ContinueOnError ErrorPolicy = iota
	// FailFast cancels remaining hosts after the first host failure (best-effort).
	FailFast
)

T type ExecResult

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type ExecResult struct {
	Stdout   []byte
	Stderr   []byte
	ExitCode int
}

ExecResult is the outcome of a remote command.

m func (ExecResult) Combined

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func (r ExecResult) Combined() []byte

Combined returns stdout followed by stderr.

T type FileMode

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type FileMode = fs.FileMode

FileMode is the permission mode used when writing remote files.

T type Flow

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type Flow struct {
	Name  string
	Steps []Step
}

Flow is an ordered, host-agnostic sequence of steps — a playbook. A Runner executes a Flow against each selected host, fanning out per host.

T type FlowCtx

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type FlowCtx struct {
	// contains filtered or unexported fields
}

FlowCtx threads through the steps of one flow execution on one host. Its param bag is private to this execution, so steps pass data forward without locking (IV3). Cross-host data goes through Shared.

f func NewFlowCtx

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func NewFlowCtx(ctx context.Context, h *Host, c Conn, opts ...FlowCtxOption) *FlowCtx

NewFlowCtx builds a FlowCtx. The Runner uses it; step tests use it directly.

m func (*FlowCtx) AnyChanged

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func (fc *FlowCtx) AnyChanged(names ...string) bool

AnyChanged reports whether any of the named earlier steps changed. With no names, it reports whether any earlier step in this flow changed. Visibility is limited to steps already executed on this host (never cross-host).

m func (*FlowCtx) Changed

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func (fc *FlowCtx) Changed(name string) bool

Changed reports whether the named earlier step changed (or would change in dry-run) during this flow execution on this host. An unrun or unrecorded step reports false.

m func (*FlowCtx) Conn

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func (fc *FlowCtx) Conn() Conn

Conn returns the live connection to the host.

m func (*FlowCtx) Ctx

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func (fc *FlowCtx) Ctx() context.Context

Ctx returns the execution context.

m func (*FlowCtx) DryRun

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func (fc *FlowCtx) DryRun() bool

DryRun reports whether this is a dry run.

m func (*FlowCtx) Get

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func (fc *FlowCtx) Get(key string) (any, bool)

Get reads a value from the per-flow param bag.

m func (*FlowCtx) Host

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func (fc *FlowCtx) Host() *Host

Host returns the target host.

m func (*FlowCtx) Log

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func (fc *FlowCtx) Log() *slog.Logger

Log returns the per-flow logger, pre-tagged by the Runner with host and step.

m func (*FlowCtx) Out

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func (fc *FlowCtx) Out() io.Writer

Out returns the human-facing output sink. The engine owns it; steps stream command output here (never os.Stdout) when asked. Never nil — io.Discard by default, so an unconfigured Runner silently discards.

m func (*FlowCtx) Prompter

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func (fc *FlowCtx) Prompter() Prompter

Prompter returns the injected prompter (non-interactive by default).

m func (*FlowCtx) Set

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func (fc *FlowCtx) Set(key string, v any)

Set stores a value in the per-flow param bag.

m func (*FlowCtx) Shared

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func (fc *FlowCtx) Shared() *SharedStore

Shared returns the cross-host store.

T type FlowCtxOption

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type FlowCtxOption func(*FlowCtx)

FlowCtxOption configures a FlowCtx.

f func WithFlowDryRun

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func WithFlowDryRun(d bool) FlowCtxOption

WithFlowDryRun toggles dry-run.

f func WithFlowLogger

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func WithFlowLogger(l *slog.Logger) FlowCtxOption

WithFlowLogger sets the per-flow logger.

f func WithFlowOutput

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func WithFlowOutput(w io.Writer) FlowCtxOption

WithFlowOutput sets the human-facing output sink steps stream to (Out()).

f func WithFlowPrompter

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func WithFlowPrompter(p Prompter) FlowCtxOption

WithFlowPrompter sets the prompter.

f func WithFlowShared

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func WithFlowShared(s *SharedStore) FlowCtxOption

WithFlowShared sets the cross-host shared store.

T type FlowResult

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type FlowResult struct {
	Flow   string
	Host   string
	Steps  []StepResult
	Status Status
	Params map[string]any
}

FlowResult is the record of one flow on one host, with a snapshot of the final param bag for pulling forward-passed data back out.

T type Host

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type Host struct {
	Name   string
	Addr   string
	Port   int
	User   string
	Tags   []string
	Groups []string
	Vars   map[string]any
}

Host is a single SSH target the orchestrator can act on.

T type Inventory

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type Inventory struct {
	// contains filtered or unexported fields
}

Inventory is the set of hosts an orchestration runs against.

f func NewInventory

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func NewInventory(hosts ...*Host) *Inventory

NewInventory builds an inventory from the given hosts.

m func (*Inventory) Add

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func (inv *Inventory) Add(h *Host)

Add appends a host to the inventory.

m func (*Inventory) Group

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func (inv *Inventory) Group(name string) []*Host

Group returns the hosts that are members of the named group.

m func (*Inventory) Hosts

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func (inv *Inventory) Hosts(sel ...Selector) []*Host

Hosts returns the hosts matching every selector (logical AND). With no selectors it returns all hosts.

T type NopReporter

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type NopReporter struct{}

NopReporter discards all events. It is the default reporter.

m func (NopReporter) FlowDone

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func (NopReporter) FlowDone(string, FlowResult)

m func (NopReporter) FlowStart

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func (NopReporter) FlowStart(string, string)

m func (NopReporter) RunDone

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func (NopReporter) RunDone(RunResult)

m func (NopReporter) StepDone

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func (NopReporter) StepDone(string, StepResult)

m func (NopReporter) StepStart

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func (NopReporter) StepStart(string, string)

T type Option

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type Option func(*Runner)

Option configures a Runner.

f func WithConcurrency

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func WithConcurrency(n int) Option

WithConcurrency caps how many hosts run at once. Values < 1 are ignored.

f func WithDialer

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func WithDialer(d Dialer) Option

WithDialer sets the dialer used to open per-host connections.

f func WithDryRun

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func WithDryRun(d bool) Option

WithDryRun toggles dry-run: steps are Checked, never Applied.

f func WithErrorPolicy

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func WithErrorPolicy(p ErrorPolicy) Option

WithErrorPolicy sets the cross-host error policy.

f func WithLogger

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func WithLogger(l *slog.Logger) Option

WithLogger sets the base structured logger.

f func WithOutput

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func WithOutput(w io.Writer) Option

WithOutput sets the human-facing output sink threaded into each flow's FlowCtx.Out(). Steps that stream (e.g. steps.Command{Stream}) write here.

f func WithPrompter

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func WithPrompter(p Prompter) Option

WithPrompter sets the prompter handed to each FlowCtx.

f func WithReporter

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func WithReporter(rep Reporter) Option

WithReporter sets the progress reporter.

T type Outcome

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type Outcome struct {
	Changed bool
	Message string
	Data    any
}

Outcome is what a step reports about what it did. The engine wraps this in a StepResult with timing and a derived Status.

T type Prompter

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type Prompter interface {
	Confirm(ctx context.Context, question string) (bool, error)
	Select(ctx context.Context, question string, options []string) (int, error)
}

Prompter answers interactive questions a step may ask. The core is non-interactive by default (PC2); a real prompter is injected by the caller.

T type PutOption

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type PutOption func(*PutOptions)

PutOption mutates PutOptions.

f func WithPutOwner

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func WithPutOwner(owner string) PutOption

WithPutOwner chowns the uploaded file to owner.

f func WithPutSudo

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func WithPutSudo() PutOption

WithPutSudo stages the upload and moves it into place with sudo.

T type PutOptions

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type PutOptions struct {
	Sudo  bool
	Owner string
}

PutOptions configures a file upload.

T type Reporter

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type Reporter interface {
	FlowStart(host, flow string)
	StepStart(host, step string)
	StepDone(host string, r StepResult)
	FlowDone(host string, r FlowResult)
	RunDone(r RunResult)
}

Reporter receives engine-driven progress events for human-facing output. It is decoupled from structured logging; the engine drives both with no step involvement (PC5).

T type RunResult

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type RunResult struct {
	Flows []FlowResult
}

RunResult aggregates one FlowResult per host.

m func (RunResult) Counts

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func (r RunResult) Counts() (ok, changed, skipped, failed int)

Counts tallies step statuses across all hosts. WouldChange counts as changed.

m func (RunResult) Failed

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func (r RunResult) Failed() bool

Failed reports whether any host's flow failed.

T type Runner

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type Runner struct {
	// contains filtered or unexported fields
}

Runner executes flows across an inventory. It pools one Conn per host and carries a SharedStore so sequential Run calls can pass data between groups (e.g. exits → relay). The Runner reaches hosts only through the Dialer/Conn interfaces, never SSH directly (IV1, PC1).

f func NewRunner

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func NewRunner(inv *Inventory, opts ...Option) *Runner

NewRunner builds a Runner. Defaults: concurrency 1, ContinueOnError, no-op reporter, non-interactive prompter, slog.Default logger.

m func (*Runner) Close

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func (r *Runner) Close() error

Close closes all pooled connections. It also satisfies steward's Stopper.

m func (*Runner) Run

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func (r *Runner) Run(ctx context.Context, flow Flow, sel ...Selector) RunResult

Run executes flow against the hosts matching sel (all hosts if none), fanning out across an ordered worker pool capped at the configured concurrency. It always returns a result per host. Under FailFast, once a host fails the run context is cancelled and hosts not yet dispatched are recorded as cancelled without dialing — because jobs are fed in inventory order, with concurrency 1 this cancellation is deterministic.

m func (*Runner) Shared

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func (r *Runner) Shared() *SharedStore

Shared returns the cross-host store, persistent across Run calls.

m func (*Runner) Stop

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func (r *Runner) Stop(context.Context) error

Stop closes pooled connections (steward Stopper).

T type Selector

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type Selector func(*Host) bool

Selector reports whether a host belongs to a selection. Selectors are pure predicates over a Host so they compose without reaching back into Inventory.

f func ByName

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func ByName(names ...string) Selector

ByName selects hosts whose Name is in names.

f func ByTag

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func ByTag(tags ...string) Selector

ByTag selects hosts carrying any of the given tags.

f func InGroup

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func InGroup(group string) Selector

InGroup selects hosts that are members of the named group.

T type SharedStore

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type SharedStore struct {
	// contains filtered or unexported fields
}

SharedStore is the cross-host, concurrency-safe param store carried by a Runner. Per-host flows publish here for later flows (e.g. exits → relay).

f func NewSharedStore

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func NewSharedStore() *SharedStore

NewSharedStore returns an empty store.

m func (*SharedStore) Get

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func (s *SharedStore) Get(key string) (any, bool)

Get reads a value.

m func (*SharedStore) Set

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func (s *SharedStore) Set(key string, v any)

Set stores a value.

T type Status

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type Status int

Status is the outcome of a step or the aggregate of a flow. 

const (
	// StatusOK — applied, no change (or all steps skipped).
	StatusOK Status = iota
	// StatusChanged — applied and state changed.
	StatusChanged
	// StatusSkipped — Check reported no change needed.
	StatusSkipped
	// StatusWouldChange — dry-run: Check reported a change; Apply was not run.
	StatusWouldChange
	// StatusFailed — Check or Apply errored.
	StatusFailed
)

m func (Status) String

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func (s Status) String() string

T type Step

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type Step interface {
	Name() string
	Check(fc *FlowCtx) (need bool, err error)
	Apply(fc *FlowCtx) (Outcome, error)
}

Step is one unit of work. Check probes whether a change is needed (need=false reports Skipped and, in dry-run, ends the step). Apply performs the change and reports what it did.

f func StepFunc

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func StepFunc(name string, fn func(*FlowCtx) (Outcome, error)) Step

StepFunc adapts a function into a Step that always applies.

T type StepResult

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type StepResult struct {
	Step     string
	Status   Status
	Outcome  Outcome
	Err      error
	Started  time.Time
	Duration time.Duration
}

StepResult is the engine's record of one step on one host.

Source Files