jschoubben
aecac5bda2
The mesh runs on the seat's bus alone (novox/hq ADR 0131, design 28 task 5.5). The old transport's consume loop, build request, tool ask, management API and account scoping are deleted, and the bus switch with them; the controller connects to the broker seat and to nothing else. The store-window tests keep their assertions on a bus-less fake, and the tests that only made sense for the old transport's in-memory holding go with it.
84 lines
2.9 KiB
Go
84 lines
2.9 KiB
Go
package broker
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import (
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"fmt"
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"strings"
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"github.com/novox/mesh-controller/internal/envfile"
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)
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// Whether this mesh's own traffic is on the bus being built.
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//
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// **One switch, read in one place** (novox/hq ADR 0116 step 5). Every seam the bus change went
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// behind ships both implementations, and until the rollout every one of them chooses the bus the
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// mesh runs on today. This is what the rollout flips, and it is deliberately a single fact rather
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// than a fact per component: a controller whose outbound is on one bus and whose inbound is on the
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// other is a mesh that hears nothing, and no test of either half would catch it.
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// NATSVar is where the controller finds the bus being built. Unset is the ordinary case and means
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// the mesh runs on the bus it has always run on.
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const NATSVar = "MESH_BUS_NATS"
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// OnNATS is the address of the bus being built, and whether the mesh is on it.
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//
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// Read from the node's own settings rather than baked in, for the reason the broker's address is
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// (novox/hq 04-ISSUES/102): an address recorded once does not follow a node's ports.
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func OnNATS() (address string, on bool, err error) {
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address, err = envfile.Placed(NATSVar)
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if err != nil {
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return "", false, err
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}
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address = strings.TrimSpace(address)
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if address == "" {
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return "", false, nil
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}
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return address, true, nil
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}
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// CredentialIn reads the user and password out of a bus address, and the address without them.
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//
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// The controller's own credential arrives in its address, the way the old bus's does. Split out so the
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// controller can record a hash of what it is actually using: its user is created by the installer at a
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// bootstrap password, before the controller exists to mint one, and a composition that left itself out
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// would produce a bus the writer cannot connect to.
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func CredentialIn(address string) (user, password, bare string) {
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at := strings.LastIndex(address, "@")
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if at < 0 {
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return "", "", address
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}
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scheme := ""
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rest := address[:at]
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if i := strings.Index(rest, "://"); i >= 0 {
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scheme, rest = rest[:i+3], rest[i+3:]
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}
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user, password, _ = strings.Cut(rest, ":")
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return user, password, scheme + address[at+1:]
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}
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// BareAddress is a bus address with any credential stripped, for something that only needs to know
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// whether a server is answering there.
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func BareAddress(address string) string {
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_, _, bare := CredentialIn(address)
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if bare == "" {
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return address
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}
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if strings.Contains(bare, "://") {
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return bare
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}
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return "nats://" + bare
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}
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// BusAddress is where the mesh's bus is, with this process's credential, and refuses to be empty:
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// there is one bus, and a control plane without it can hold records and answer nothing (novox/hq
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// ADR 0131, design 28 task 5.5).
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func BusAddress() (string, error) {
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address, _, err := OnNATS()
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if err != nil {
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return "", err
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}
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if address == "" {
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return "", fmt.Errorf("this control plane has no %s, so it cannot reach the mesh's bus", NATSVar)
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}
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return address, nil
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}
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