mesh-controller/cmd/mesh-controller/compose_input.go

package main

import (
	"context"
	"os"
	"sort"
	"strings"

	"git.novox.be/novox/mesh-sdk/go/catalogue"
	"git.novox.be/novox/mesh-sdk/go/compose"
	"git.novox.be/novox/mesh-sdk/go/overlay"
	"github.com/novox/mesh-controller/internal/inventory"
)

// The controller's adapter from its stores to mesh-sdk's composition input (novox/hq ADR 0453 clause 3, design 47 R4b,
// issues 1382 and 1383).
//
// **The adapter reads, and perform writes.** readComposeInput asks the stores once for everything the composition reads
// and returns compose.Input, which the composition never changes; it makes, seals, allocates and records nothing. A
// pair credential, a port, an own secret or a core box that the next send would make is not made here: the composition
// names it foreseen, and compose_perform.go makes it for a send, then reads the stores again and composes again. A
// question (status, facts, probes, the merge gate's reading) never performs.
//
// **The Input is built once per operation.** A verb that composes every node reads the stores once and hands the Input to
// each node's composition of it.

// composeInputBuilt is called once for each Input the adapter builds: the seam a test counts the reads of an operation by
// (issue 1382, criterion 5).
var composeInputBuilt = func() {}

// readComposeInput reads the stores once and returns what the composition needs. ctx carries what a send keeps (the
// recorded modules kept at the build their machine runs, recorded_kept.go): the same contexts every send composes under.
func readComposeInput(ctx context.Context, open *stores) (*meshInput, error) {
	in, shape, err := readMeshAndNodes(ctx, open)
	if err != nil {
		return nil, err
	}
	// What each node resolves to, with no credential given (the settings are read before it): the modules whose settings are read, and the
	// needs whose pair credentials are asked of the stores. Nothing is written by it.
	unread, err := readSettings(ctx, open, &in)
	if err != nil {
		return nil, err
	}
	plans := map[string]compose.Resolved{}
	for _, n := range in.Nodes {
		if shape.refused[n.Name] != nil {
			continue // refused for what it keeps: nothing of it is read further
		}
		resolved, err := compose.Resolve(in, n.Name)
		switch {
		case compose.IsUnresolvable(err):
			// Their set does not compose: nothing of theirs is read further, as the controller never read a thing for a
			// node that did not resolve.
			continue
		case err != nil:
			return nil, err
		}
		plans[n.Name] = resolved
	}
	if err := unreadSettings(unread, plans); err != nil {
		return nil, err
	}
	var busRefused error
	wouldMake, err := readCredentialsAndBuilds(ctx, open, &in, plans, shape, &busRefused)
	if err != nil {
		return nil, err
	}
	composeInputBuilt()
	return &meshInput{Input: in, wouldMake: wouldMake, busRefused: busRefused, refused: shape.refused}, nil
}

// meshInput is the Input an operation composes over, and the pair credentials its reading found none held for: the ones the
// next send makes, which perform makes.
type meshInput struct {
	compose.Input
	wouldMake []inventory.PairCredential
	// busRefused is why the bus's user list cannot be composed (no user has a credential): the machine that runs the bus is
	// refused with it, as the controller's own composition refused it, and no other machine is.
	busRefused error
	// refused is, by node, why that machine alone cannot be composed (nodeRefusal).
	refused map[string]error
}

// nodeOf is the node of that name in an Input.
func nodeOf(in compose.Input, name string) (compose.Node, bool) {
	for _, n := range in.Nodes {
		if n.Name == name {
			return n, true
		}
	}
	return compose.Node{}, false
}

// inputShape is what the first half of the reading found that the second half needs.
type inputShape struct {
	sent    map[string]map[string]string // by node: module to the commit last sent
	kept    map[string]map[string]string // by node: module to the commit kept
	current map[string]inventory.CurrentBuild
	// refused is, by node, why a recorded module cannot be kept at the build the machine runs (keepRecorded's refusal, in
	// its words): that machine alone is refused with it, as planFor refused it, and nothing else of the mesh is.
	refused map[string]error
}

// readMeshAndNodes is the mesh-wide and per-node half of the Input (issue 1382).
func readMeshAndNodes(ctx context.Context, open *stores) (compose.Input, inputShape, error) {
	inv := open.inventory
	var in compose.Input
	shape := inputShape{sent: map[string]map[string]string{}, kept: map[string]map[string]string{}, refused: map[string]error{}}

	shelf, err := inv.Catalogue(ctx)
	if err != nil {
		return in, shape, err
	}
	in.Catalogue = shelf
	if in.Holdings, err = inv.Holdings(ctx); err != nil {
		return in, shape, err
	}
	if in.Licences, err = readLicences(ctx, open); err != nil {
		return in, shape, err
	}

	nodes, err := inv.Nodes(ctx)
	if err != nil {
		return in, shape, err
	}
	places, err := inv.Overlays(ctx)
	if err != nil {
		return in, shape, err
	}
	placed := map[string]inventory.Overlay{}
	for _, p := range places {
		placed[p.Name] = p
	}
	if shape.current, err = inv.CurrentBuilds(ctx); err != nil {
		return in, shape, err
	}

	// The range the mesh allocates from and what its internal names end in, read from the environment here and nowhere else.
	in.OverlayCIDR = strings.TrimSpace(os.Getenv(OverlayCIDRVar))
	in.InternalSuffix = overlay.Suffix()
	if in.Tunnels, err = readTunnels(ctx, inv); err != nil {
		return in, shape, err
	}
	if in.Adopted, err = readAdopted(ctx, inv); err != nil {
		return in, shape, err
	}
	carried, err := inv.CarriedPeers(ctx)
	if err != nil {
		return in, shape, err
	}
	for _, c := range carried {
		in.CarriedPeers = append(in.CarriedPeers, compose.CarriedPeer{
			PublicKey: c.PublicKey, Address: c.Address, EnrolledAs: c.EnrolledAs, Named: c.Named})
	}
	if in.Joining, err = inv.NodesWithALiveToken(ctx); err != nil {
		return in, shape, err
	}

	keepsSecrets := false
	for _, m := range shelf {
		keepsSecrets = keepsSecrets || m.Keeps != ""
	}

	for _, n := range nodes {
		var refusal error
		node, err := readNode(ctx, open, n, placed[n.Name], &refusal)
		if err != nil {
			return in, shape, err
		}
		if refusal != nil {
			shape.refused[n.Name] = refusal
		}
		shape.sent[n.Name], shape.kept[n.Name] = node.SentBuilds, node.KeptBuilds
		in.Nodes = append(in.Nodes, node)
	}
	if keepsSecrets {
		if in.OperatorExport, err = inv.OperatorExport(ctx); err != nil {
			return in, shape, err
		}
	}
	return in, shape, nil
}

// readNode is one node of the Input: everything the composition reads about it, in the order the controller read it.
func readNode(ctx context.Context, open *stores, n inventory.Node, place inventory.Overlay,
	refused *error) (compose.Node, error) {
	inv := open.inventory
	out := compose.Node{
		Name: n.Name,
		Place: compose.Place{Key: place.Key, Endpoint: place.Endpoint, Site: place.Site, Hub: place.Hub,
			Address: place.Address},
		Account: n.Account, AccountHome: n.AccountHome, AgentAccount: n.AgentAccount, AgentAccountHome: n.AgentAccountHome,
		Adopted: n.Adopted,
	}
	var err error
	if out.Assigned, err = inv.Assigned(ctx, n.Name); err != nil {
		return out, err
	}
	if out.Capabilities, err = inv.ProfileOf(ctx, n.Name); err != nil {
		return out, err
	}
	if out.PublicDomain, err = inv.PublicDomainOf(ctx, n.Name); err != nil {
		return out, err
	}
	if out.Pins, err = inv.PinsFor(ctx, n.Name); err != nil {
		return out, err
	}
	if out.Bound, err = inv.BindingsFor(ctx, n.Name); err != nil {
		return out, err
	}
	given, err := inv.PortsFor(ctx, n.Name)
	if err != nil {
		return out, err
	}
	for _, a := range given {
		if out.Ports == nil {
			out.Ports = map[string]map[int]int{}
		}
		if out.Ports[a.Module] == nil {
			out.Ports[a.Module] = map[int]int{}
		}
		out.Ports[a.Module][a.Wanted] = a.Machine
	}
	if out.SealingKey, err = inv.SealingKeyOf(ctx, n.Name); err != nil {
		return out, err
	}
	if n.Adopted {
		if out.Taken, err = inv.Taken(ctx, n.Name); err != nil {
			return out, err
		}
	}
	if out.OutwardLinks, err = inv.OutwardLinksOf(ctx, n.Name); err != nil {
		return out, err
	}
	account, had, err := inv.MachineOf(ctx, n.Name)
	if err != nil {
		return out, err
	}
	if had && account.Machine != nil {
		out.NetworksSaid = true
		for _, a := range account.Machine.Networks {
			out.Networks = append(out.Networks, catalogue.AttachedNetwork{Link: a.Link, Network: a.Network})
		}
	}
	if out.Sequence, err = inv.Sequence(ctx, n.ID); err != nil {
		return out, err
	}
	if out.Epoch, err = inv.SentEpoch(ctx, n.ID); err != nil {
		return out, err
	}
	if out.Generation, err = inv.SentGeneration(ctx, n.ID); err != nil {
		return out, err
	}
	if out.ReadsModules, err = inv.ReadsModules(ctx, n.ID); err != nil {
		return out, err
	}
	if out.SentBuilds, out.SentKnown, err = inv.SentBuilds(ctx, n.Name); err != nil {
		return out, err
	}
	runs, err := inv.AssignmentRuns(ctx, n.Name)
	if err != nil {
		return out, err
	}
	if len(runs) > 0 {
		out.Runs = make(map[string]compose.Run, len(runs))
		for module, ref := range runs {
			out.Runs[module] = compose.Run{Commit: ref.Commit, Build: ref.Build}
		}
	}
	// A recorded module kept at the build this machine runs, in the context a send composes under (recorded_kept.go): its
	// manifest and the commit, applied to this node's own resolution only.
	// What cannot be kept refuses this machine alone (keepRecorded's refusal, as planFor returned it).
	kept, err := recordedKept(ctx, open, n.Name)
	if err != nil {
		*refused = err
	} else if len(kept) > 0 {
		out.KeptBuilds = kept
		if out.Kept, err = keptManifests(ctx, open, n.Name, kept); err != nil {
			*refused = err
			out.KeptBuilds, out.Kept = nil, nil
		}
	}
	stated, has, err := inv.HealthOf(ctx, n.Name)
	if err != nil {
		return out, err
	}
	out.Stated = has
	if has {
		out.Contract = stated.Contract
	}
	return out, nil
}

// keptManifests is the manifest of each module kept at the build a machine runs: keepRecorded's reads, and its refusals in its
// words, without putting any of it into a shelf (that is the node's own Kept, applied by the composition).
func keptManifests(ctx context.Context, open *stores, node string, kept map[string]string) (map[string]catalogue.Manifest, error) {
	// applyKept puts each manifest into the shelf it is given and refuses a build that cannot be read; the shelf here is a
	// scratch one, whose entries are the kept manifests.
	scratch := map[string]catalogue.Manifest{}
	if err := applyKept(ctx, open, node, kept, scratch); err != nil {
		return nil, err
	}
	return scratch, nil
}

func readTunnels(ctx context.Context, inv *inventory.Inventory) (map[string]compose.FoundTunnel, error) {
	found, err := inv.Tunnels(ctx)
	if err != nil {
		return nil, err
	}
	if len(found) == 0 {
		return nil, nil
	}
	out := make(map[string]compose.FoundTunnel, len(found))
	for name, t := range found {
		out[name] = compose.FoundTunnel{Tunnel: tunnelOf(t.Tunnel), NodeAdopted: t.NodeAdopted}
	}
	return out, nil
}

func readAdopted(ctx context.Context, inv *inventory.Inventory) (*compose.AdoptedTunnel, error) {
	tunnel, hub, adopted, err := inv.AdoptedTunnel(ctx)
	if err != nil {
		return nil, err
	}
	if hub == "" {
		return nil, nil
	}
	return &compose.AdoptedTunnel{Tunnel: tunnelOf(tunnel), Hub: hub, Adopted: adopted}, nil
}

func tunnelOf(t inventory.Tunnel) compose.Tunnel {
	out := compose.Tunnel{Interface: t.Interface, Unit: t.Unit, Config: t.Config, Port: t.Port, MTU: t.MTU,
		Address: t.Address, Range: t.Range, PublicKey: t.PublicKey}
	for _, p := range t.Peers {
		out.Peers = append(out.Peers, compose.TunnelPeer{PublicKey: p.PublicKey, Address: p.Address})
	}
	return out
}

// readLicences is every licence the mesh holds, with who uses it and the key sealed to each holder: given even where empty,
// so a holder the mesh holds no key for composes as that, and not as a key that was not asked for.
func readLicences(ctx context.Context, open *stores) ([]compose.Licence, error) {
	held, err := open.Licences(ctx)
	if err != nil {
		return nil, err
	}
	all, err := held.All(ctx)
	if err != nil {
		return nil, err
	}
	var out []compose.Licence
	for _, one := range all {
		l := compose.Licence{Name: one.Name, Serves: one.Serves, Keys: map[compose.Holder]string{}}
		holders, err := held.HoldersOf(ctx, one.Name)
		if err != nil {
			return nil, err
		}
		for _, h := range holders {
			holder := compose.Holder{Node: h.Node, Module: h.Module}
			l.Holders = append(l.Holders, holder)
			key, err := held.KeyFor(ctx, one.Name, h.Node, h.Module)
			if err != nil {
				return nil, err
			}
			l.Keys[holder] = key
		}
		node, module, err := held.ManagerOf(ctx, one.Name)
		if err != nil {
			return nil, err
		}
		l.Manager = compose.Holder{Node: node, Module: module}
		out = append(out, l)
	}
	return out, nil
}

// readSettings is each node's settings layers for every module that has any (a row, or config in mesh-config), read BEFORE any node is resolved: the first pass
// resolves a node whose set takes a provider's served facts from the node that runs it, with that node's settings on them
// (servedOnNode), so a mesh whose provider says ${setting:domain} resolves only with the settings in the Input. A module's
// settings that fail to read are returned in unread, by node and module, and are an error only for a module a node resolves to
// (unreadSettings): the controller read none for a module nothing runs.
func readSettings(ctx context.Context, open *stores, in *compose.Input) (unread map[string]map[string]error, err error) {
	have, err := open.inventory.ModulesWithSettings(ctx)
	if err != nil {
		return nil, err
	}
	names, err := modulesToRead(in.Catalogue, have, func(module string) (bool, error) {
		return open.inventory.ReadsConfig(ctx, module)
	})
	if err != nil {
		return nil, err
	}
	for i := range in.Nodes {
		n := &in.Nodes[i]
		for _, module := range names {
			layers, err := open.inventory.SettingsFor(ctx, n.Name, module)
			if err != nil {
				if unread == nil {
					unread = map[string]map[string]error{}
				}
				if unread[n.Name] == nil {
					unread[n.Name] = map[string]error{}
				}
				unread[n.Name][module] = err
				continue
			}
			if len(layers) == 0 {
				continue
			}
			if n.Settings == nil {
				n.Settings = map[string][]catalogue.Layer{}
			}
			n.Settings[module] = layers
		}
	}
	return unread, nil
}

// modulesToRead is the modules on the shelf whose settings are read for a node: those with a settings row, and those in
// the config form whose values mesh-config holds (readsConfig), which have no row when they were never in the settings
// form (issue 1493: brother's scanner and printer, set only in mesh-config, composed empty). SettingsFor is where
// mesh-config's values are laid in, so a gate on the settings table alone leaves them out.
func modulesToRead(shelf map[string]catalogue.Manifest, have map[string]bool, readsConfig func(string) (bool, error)) ([]string, error) {
	names := make([]string, 0, len(have))
	for module, m := range shelf {
		if have[module] {
			names = append(names, module)
			continue
		}
		if !m.DeclaresConfig() {
			continue
		}
		reads, err := readsConfig(module)
		if err != nil {
			return nil, err
		}
		if reads {
			names = append(names, module)
		}
	}
	sort.Strings(names)
	return names, nil
}

// unreadSettings is the error of a module's settings that did not read, for a module the node resolves to.
func unreadSettings(unread map[string]map[string]error, plans map[string]compose.Resolved) error {
	names := make([]string, 0, len(plans))
	for node := range plans {
		names = append(names, node)
	}
	sort.Strings(names)
	for _, node := range names {
		for _, m := range plans[node].Plan.Modules {
			if err := unread[node][m.Module]; err != nil {
				return err
			}
		}
	}
	return nil
}