Files
mesh-controller/internal/broker/provisioner.go
T
mesh-tools 97a2d841c7 Land feature 57's controller work on its release branch
The controller plans config, templates and moved providers' provisions,
hands bus accounts to the vault and judges the new manifest words, on the
feature's SDK and node-engine validator (feature 57, config and provisioning).
2026-10-15 21:27:33 +00:00

213 lines
12 KiB
Go

package broker
import (
"errors"
"fmt"
"strings"
"github.com/nats-io/nats.go"
)
// The provisioner client's own bus account (novox/hq ADR 0349 clauses 6 and 11, design 57 package P3).
//
// **Not the tool runner's account.** The client fills a machine's files and asks the vault for the secrets that
// machine's declaration names; the vault hands a secret only to an account of its own, because a call under the
// tool runner's account cannot be told from an agent's on that machine (ADR 0305 §3, §12). So each machine that
// runs the client has a principal of its own, KindProvisioner, named for the machine, and granted what the client
// does and nothing else: read its own machine's keys in each domain's bucket, write its own machine's keys of the
// provisioner server's needs, applied and collections (design 57 P4), read the server's registry, say what it
// applied on its own machine, and ask the vault in its own name.
// NodeProvisionerSeat is the seat the provisioner client holds on every machine (ADR 0349 clause 3).
const NodeProvisionerSeat = "node-provisioner"
// ProvisionerSecret is the own secret of the module running the client that its bus account is delivered in, as
// `broker` is a module's own (novox/hq issue 195): a module that claims NodeProvisionerSeat and declares no own
// secret of this name has nowhere to read an account, and is given none.
const ProvisionerSecret = "provisioner-broker"
// ConfigResolvedBucket is the config domain's resolved values, keyed `<node>.<module>.<key>` (ADR 0348, research
// 051): mesh-config's state `resolved`, written by mesh-config alone.
var ConfigResolvedBucket = BucketName("mesh-config", "resolved")
// ProvisionerReads are the domains' buckets a provisioner client reads its own machine's keys of, each keyed
// `<node>.…` (research 051): placement, the controller's assignments mirror (`<node>.<module>`), whose value carries
// the provisioner's plan of a module handed to it (inventory.Provisioning, design 57 P5); and config,
// mesh-config's resolved values. **Named one by one**, as the controller's asks are: a domain that moves to the
// provisioner adds its bucket here, and a bucket not named is one the client cannot read.
var ProvisionerReads = []string{ConfigResolvedBucket}
// ProvisionerReadsWhole are the buckets a provisioner client reads every key of: the controller's assignments mirror,
// where a provider's consumers are bound to it in their own machines' plans, which the provider machine's client
// reads to fill ${consumers:<provision>} with each one's credential (novox/hq ADR 0373, issue 679). It holds placement
// and plans, never a secret's value; the client writes none of it.
var ProvisionerReadsWhole = []string{AssignmentsBucket}
// BoundState is a providing module's state of entries, one per consumer (mesh-sdk go/provider, issue 678): a
// consumer's machine's client reads its own keys of it, `<node>.<module>.<provision>[.<local>]`, to fill
// ${bound:<provision>:<key>} (issue 679).
const BoundState = "bound"
// ProvisionerServerModule is the module holding the seat mesh-provisioner once for the mesh (ADR 0349 clause 3,
// design 57 P4), whose buckets the clients write their own machine's keys of.
const ProvisionerServerModule = "mesh-provisioner"
// The provisioner server's buckets (ADR 0349 clause 3): its state, created by the controller from its manifest
// like any module's, and written by its own account whole.
var (
// ProvisionerRegistryBucket is which domain answers which kind of placeholder, keyed by the kind; the
// server's alone, read whole by every client.
ProvisionerRegistryBucket = BucketName(ProvisionerServerModule, "registry")
// ProvisionerNeedsBucket is what each module on each machine needs, `<node>.<module>.<kind>.<name>`.
ProvisionerNeedsBucket = BucketName(ProvisionerServerModule, "needs")
// ProvisionerAppliedBucket is what is applied where, `<node>.<module>`.
ProvisionerAppliedBucket = BucketName(ProvisionerServerModule, "applied")
// ProvisionerCollectBucket is the items of every collection, `<node>.<collection>.<contributor>`.
ProvisionerCollectBucket = BucketName(ProvisionerServerModule, "collect")
)
// ProvisionerWrites are the server's buckets a client writes, and reads, its own machine's keys of (`<node>.>`)
// and no other's: the needs it records, what it applied, and the items of the collections on its machine. A
// client cannot write another machine's needs, or say another machine applied a file.
var ProvisionerWrites = []string{ProvisionerNeedsBucket, ProvisionerAppliedBucket, ProvisionerCollectBucket}
// VerbsTheProvisionerAsksTheVault are the vault's verbs a provisioner client asks in its own name (ADR 0349
// clause 11): `get`, a secret its machine's declaration names, answered sealed to the asker's key. On the subject
// that names its caller, so the vault knows which machine's client asks from the bus's word.
var VerbsTheProvisionerAsksTheVault = []SeatVerb{{Seat: "mesh-vault", Verb: "get"}}
// VaultSecretChangedSubject is where the vault says a secret it holds changed (`secret-changed`: which, by whom,
// when, its generation; never a value, ADR 0349 clause 11), as link.EventSubject addresses mesh-vault's event. A
// provisioner client listens to it so a rotated secret reaches its file without a new declaration (design 57 V4):
// it asks the vault again, in its own name, for a secret its machine's declaration names.
const VaultSecretChangedSubject = "mesh.mod.mesh-vault.event.secret-changed"
// ProvisionerAppliedSubject is where a machine's client says what it applied for one module, applied or failed
// with the reason (ADR 0349 clauses 4 and 15): `prov.applied.<node>.<module>`.
func ProvisionerAppliedSubject(node, module string) string {
return "prov.applied." + node + "." + module
}
// ProvisionerAskSubject is where a machine's tool runner asks that machine's provisioner client for a config value
// or a non-secret bound value of a module it carries, naming the module from the bundle that asks (novox/hq ADR
// 0370 §1, §3, §4; issue 685): `prov.ask.<node>`, which the client subscribes and the tool runner's account of the
// same machine alone may publish. The bus proves only that the tool runner asks; the module is the runtime's word,
// so the client answers no secret here (ADR 0370 §2).
func ProvisionerAskSubject(node string) string { return "prov.ask." + node }
// ProvisionerChangedSubject is where a machine's client says that a value of one module it answers moved, so the
// tool runner asks again for the module's code's watches (ADR 0349 §14, ADR 0370 §1): `prov.changed.<node>.<module>`,
// carrying which value and never the value itself, heard by that machine's tool runner alone.
func ProvisionerChangedSubject(node, module string) string {
return "prov.changed." + node + "." + module
}
// provisionerGrants is a provisioner client's whole authority: to publish, and to subscribe.
func provisionerGrants(p Principal) (pub, sub []string, err error) {
if p.Node == "" {
// Refused rather than composed into `$KV.<bucket>..>`, a pattern no machine's keys are under, and a
// name every nameless client would share.
return nil, nil, errors.New("a provisioner client names no machine, so it would have no keys of its own " +
"to read and an account it shared with every other")
}
for _, bucket := range ProvisionerReads {
pub = append(pub, machineKeysRead(bucket, p.Node)...)
}
for _, bucket := range ProvisionerReadsWhole {
pub = append(pub, wholeBucketRead(bucket)...)
}
for _, bucket := range p.BoundBuckets {
module, name, ok := strings.Cut(bucket, "_")
if !ok || name != BoundState || !safeSubject.MatchString(module) || strings.Contains(module, "_") {
return nil, nil, fmt.Errorf("%q is not a provider's bucket of entries, <module>_%s", bucket, BoundState)
}
pub = append(pub, machineKeysRead(bucket, p.Node)...)
}
// The server's buckets (design 57 P4): its own machine's keys of the needs, the applied and the
// collections, read and written, `$KV.<bucket>.<node>.>` and nothing wider; and the registry, read whole,
// which says which domain answers which kind and is the same for every machine.
for _, bucket := range ProvisionerWrites {
pub = append(pub, machineKeysRead(bucket, p.Node)...)
pub = append(pub, "$KV."+bucket+"."+p.Node+".>")
}
pub = append(pub, wholeBucketRead(ProvisionerRegistryBucket)...)
pub = append(pub, "prov.applied."+p.Node+".>")
token := CallerToken(p.Username())
if token == "" {
return nil, nil, fmt.Errorf("%q cannot name a caller", p.Username())
}
for _, v := range VerbsTheProvisionerAsksTheVault {
pub = append(pub, "mesh.seat."+v.Seat+"."+CallKind+"."+v.Verb+"."+token)
}
// What moved of a value it answers its own machine's tool runner (ADR 0370 §1), under its own machine's name.
pub = append(pub, "prov.changed."+p.Node+".>")
// Its own reply space, for the vault's answers and its reads' and watches' deliveries; what the vault says
// changed; and its own machine's tool runner asking it for a module's config and non-secret bound values (ADR
// 0370 §3), which it answers on the ask's reply and nowhere else.
return pub, []string{p.inbox(), VaultSecretChangedSubject, ProvisionerAskSubject(p.Node)}, nil
}
// machineKeysRead is reading every key of a bucket under one machine's name, `<node>.>`, and no other key: a
// direct get of a key's own subject, and a consumer whose filter is under it — the server's create-with-filter
// form, which it holds to the filter the subject names (as stateGrants does for one key, novox/hq ADR 0260).
// Binding, deleting a consumer and flow control cannot be narrowed by key and read no value.
func machineKeysRead(bucket, node string) []string {
stream := "KV_" + bucket
keys := "$KV." + bucket + "." + node + ".>"
return []string{
"$JS.API.STREAM.INFO." + stream,
"$JS.API.DIRECT.GET." + stream + "." + keys,
"$JS.API.CONSUMER.CREATE." + stream + ".*." + keys,
"$JS.API.CONSUMER.DELETE." + stream + ".>",
"$JS.FC." + stream + ".>",
}
}
// wholeBucketRead is reading every key of a bucket and writing none: what stateGrants grants a module for a
// bucket it `reads`.
func wholeBucketRead(bucket string) []string {
stream := "KV_" + bucket
return []string{
"$JS.API.STREAM.INFO." + stream,
"$JS.API.DIRECT.GET." + stream + ".>",
"$JS.API.CONSUMER.CREATE." + stream + ".>",
"$JS.API.CONSUMER.DELETE." + stream + ".>",
"$JS.FC." + stream + ".>",
}
}
// LastProvApplied is what a machine's provisioner client last said of one module's files, as it published it on
// ProvisionerAppliedSubject and ProvAppliedStream keeps it (design 57 P6): false when it has said nothing of it in
// the stream's week.
func LastProvApplied(js nats.JetStreamContext, node, module string) ([]byte, bool, error) {
msg, err := js.GetLastMsg(ProvAppliedStream, ProvisionerAppliedSubject(node, module))
if errors.Is(err, nats.ErrMsgNotFound) {
return nil, false, nil
}
if err != nil {
return nil, false, fmt.Errorf("what %s's provisioner client said of %s cannot be read: %w", node, module, err)
}
return msg.Data, true, nil
}
// ProvAppliedReports is the newest word of every machine's provisioner client on every module it said one of, kept by
// ProvAppliedStream, by subject (`prov.applied.<node>.<module>`).
func ProvAppliedReports(js nats.JetStreamContext) (map[string][]byte, error) {
info, err := js.StreamInfo(ProvAppliedStream, &nats.StreamInfoRequest{SubjectsFilter: ProvAppliedSubjects})
if err != nil {
return nil, fmt.Errorf("the provisioner clients' reports cannot be listed: %w", err)
}
out := map[string][]byte{}
for subject := range info.State.Subjects {
msg, err := js.GetLastMsg(ProvAppliedStream, subject)
if errors.Is(err, nats.ErrMsgNotFound) {
continue // aged out between the two reads
}
if err != nil {
return nil, fmt.Errorf("the provisioner client's report on %s cannot be read: %w", subject, err)
}
out[subject] = msg.Data
}
return out, nil
}