| 1 | package host |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "encoding/base64" |
| 6 | "encoding/json" |
| 7 | "errors" |
| 8 | "fmt" |
| 9 | "net/http" |
| 10 | "strings" |
| 11 | "sync" |
| 12 | "time" |
| 13 | |
| 14 | "github.com/carlosframework/platform/internal/hostactors" |
| 15 | "github.com/carlosframework/platform/internal/hostenv" |
| 16 | "github.com/carlosframework/platform/internal/registry" |
| 17 | "github.com/carlosframework/platform/internal/release" |
| 18 | "github.com/carlosframework/platform/internal/status" |
| 19 | ) |
| 20 | |
| 21 | // A box its region's group launched is referenced by its group reference |
| 22 | // (census ruling region-ha-2b): hostactors.GroupBoxReference of its account |
| 23 | // and instance, "g-" and 20 hex digits. Its host.env says so: |
| 24 | // carlos system host-env write adds CARLOS_BOX_REFERENCE=group. Status |
| 25 | // labels come from 1,600 values and identity records are never deleted, so |
| 26 | // as a group replaces its boxes, labels collide and a box whose label |
| 27 | // another record holds can never publish its own; group references don't |
| 28 | // collide, and are a pseudonym, so the public status feed shows no |
| 29 | // instance id. Every other box, fleet boxes included, keeps its label and |
| 30 | // its status key exactly as before. |
| 31 | |
| 32 | // groupReferenced reports whether this box takes its group reference. |
| 33 | func groupReferenced(getenv func(string) string) bool { |
| 34 | return strings.TrimSpace(getenv(hostenv.BoxReference)) == hostenv.GroupReference |
| 35 | } |
| 36 | |
| 37 | // groupIdentity reads this box's account and instance from its signed |
| 38 | // identity document (IMDS); a seam for tests. |
| 39 | var groupIdentity = func() (account, instance string, err error) { |
| 40 | rec, err := readIdentityRecord(&http.Client{Timeout: 2 * time.Second}, imdsBase, "", time.Now()) |
| 41 | if err != nil { |
| 42 | return "", "", err |
| 43 | } |
| 44 | doc, err := base64.StdEncoding.DecodeString(rec.IdentityDocument) |
| 45 | if err != nil { |
| 46 | return "", "", err |
| 47 | } |
| 48 | var d struct { |
| 49 | AccountID string `json:"accountId"` |
| 50 | InstanceID string `json:"instanceId"` |
| 51 | } |
| 52 | if err := json.Unmarshal(doc, &d); err != nil { |
| 53 | return "", "", err |
| 54 | } |
| 55 | if d.AccountID == "" || d.InstanceID == "" { |
| 56 | return "", "", errors.New("the identity document names no account or instance") |
| 57 | } |
| 58 | return d.AccountID, d.InstanceID, nil |
| 59 | } |
| 60 | |
| 61 | var groupRef struct { |
| 62 | sync.Mutex |
| 63 | ref string |
| 64 | } |
| 65 | |
| 66 | // groupBoxReference is this box's group reference, read once and kept. "" |
| 67 | // while IMDS has not answered: never a label in its place. |
| 68 | func groupBoxReference() string { |
| 69 | ref, _ := resolveGroupBoxReference() |
| 70 | return ref |
| 71 | } |
| 72 | |
| 73 | // resolveGroupBoxReference is groupBoxReference with the reason it has |
| 74 | // none: the IMDS read's error, kept so the caller can say why. Only a |
| 75 | // success is kept; a failure is asked again next time. |
| 76 | func resolveGroupBoxReference() (string, error) { |
| 77 | groupRef.Lock() |
| 78 | defer groupRef.Unlock() |
| 79 | if groupRef.ref != "" { |
| 80 | return groupRef.ref, nil |
| 81 | } |
| 82 | account, instance, err := groupIdentity() |
| 83 | if err != nil { |
| 84 | return "", err |
| 85 | } |
| 86 | groupRef.ref = hostactors.GroupBoxReference(account, instance) |
| 87 | return groupRef.ref, nil |
| 88 | } |
| 89 | |
| 90 | // errNoGroupReference is a tick of a group box whose reference has not |
| 91 | // resolved: it publishes nothing. |
| 92 | var errNoGroupReference = errors.New("this group box's reference could not be read, so it publishes no status report this tick") |
| 93 | |
| 94 | // groupStatusTick is statusLoop's tick (census ruling region-ha-2b). A box |
| 95 | // whose host.env carries the group marker publishes its status report |
| 96 | // only under its group reference, the key the console derives, resolved |
| 97 | // afresh on every tick until it resolves (groupBoxReference keeps only a |
| 98 | // success). Until then it publishes nothing at all: never under |
| 99 | // status.Label, which may be another box's key, since WriteBox replaces |
| 100 | // whatever is there. That holds whatever the claim and region HA switches |
| 101 | // say. Every other box's tick is statusTick's with statusLoop's label, |
| 102 | // exactly as before. |
| 103 | func groupStatusTick(ctx context.Context, s release.Store, reg *registry.Registry, p status.Probes, publish bool, label string, getenv func(string) string) error { |
| 104 | if groupReferenced(getenv) { |
| 105 | ref, err := resolveGroupBoxReference() |
| 106 | if err != nil { |
| 107 | return fmt.Errorf("%w: %v", errNoGroupReference, err) |
| 108 | } |
| 109 | label = ref |
| 110 | } |
| 111 | return statusTick(ctx, s, reg, p, publish, label) |
| 112 | } |
| 113 | |
amadan