Compose a process's environment as a container's

A module's own code moving out of its container (novox/hq to-be 38 WP4c)
becomes a process on the machine, and still has to be told what its
container was: the port this machine gave the module and where the
foundation's seats are. ${port:…} and ${seat:…} were filled only in a
file's content and a container's env, so in a process's env they reached
the machine as literals, and the modules that moved first (mesh-catalog
#245) wrote their run-once steps a 0600 env file instead. A process's env
now takes the same resolution and the same refusals; ${dir:…} and
${access:…} already did, and a bundle's env (ADR 0192) already resolves
${dir:…} and ${port:…}.
This commit is contained in:
jochen
2026-10-04 00:27:42 +02:00
parent 6a803ea5b3
commit cdebb7d1a5
3 changed files with 95 additions and 10 deletions
+10 -5
View File
@@ -31,7 +31,7 @@ import (
//
// So a module asks. `${port:8080}` is "the machine-side port you gave me for the 8080 I said I
// listen on", and the module writes that where it would otherwise have written a literal — in a
// file's content, or in a value of a container's `env`.
// file's content, or in a value of a container's or a process's `env`.
//
// **The environment is filled by the control plane, exactly as a bound value is.** A port is not
// secret — the mesh holds it in the clear — so there is nothing for the host to be the only
@@ -64,7 +64,12 @@ func portsUsed(content string) []int {
}
// portInto replaces a resource's ${port:…} placeholders with what this machine assigned — in a
// file's content, and in a value of a container's environment.
// file's content, and in a value of a container's or a process's environment.
//
// **A process's environment is a container's** (novox/hq to-be 38 WP4c). A module's code moving out
// of its container becomes a process on the machine and still has to be told what the container
// was told; filled for one kind and not the other, the literal reached the process and was read as
// a port, and the modules that moved first wrote their run-once steps a 0600 env file instead.
//
// A port the module did not say it listens on is refused, for the same reason a binding's unknown
// key is: the module is asking about something it never declared, and the answer would be a guess.
@@ -84,7 +89,7 @@ func portInto(resource map[string]any, module string, listens []Listening, with
}
resource["content"] = filled
case "container":
case "container", "process":
env, ok := resource["env"].(map[string]any)
if !ok {
return nil
@@ -106,8 +111,8 @@ func portInto(resource map[string]any, module string, listens []Listening, with
continue
}
value, err := portsFilledInto(written,
fmt.Sprintf("%s's container %s sets %s to something that",
module, resource["name"], key), module, listens, with)
fmt.Sprintf("%s's %s %s sets %s to something that",
module, resource["type"], resource["name"], key), module, listens, with)
if err != nil {
return err
}
+80
View File
@@ -0,0 +1,80 @@
package catalogue
import (
"strings"
"testing"
)
// **A process's environment is composed as a container's is** (novox/hq to-be 38 WP4c).
//
// A module's code moving out of its container becomes a process on the machine, and what its
// container's environment asked for — the port this machine gave the module, the place it put the
// module's directory — it still has to be told. Filled for a container and not for a process, the
// literal `${port:8080}` reached the process as its environment and was read as a port; the modules
// that moved first wrote their run-once steps an env file instead.
func processModule(env map[string]any) Manifest {
return Manifest{
Module: "showcase",
Listens: []Listening{{Port: 8080, From: FromMesh}},
Resources: []map[string]any{
{"id": "data", "type": "directory", "mode": "0700"},
{"id": "setup", "type": "process", "name": "showcase-setup", "run-once": true,
"run": []any{"/usr/bin/showcase", "setup"}, "env": env},
},
}
}
func TestAProcessIsToldItsPortAndItsPlaceInItsEnvironment(t *testing.T) {
env := map[string]any{
"SHOWCASE_URL": "http://127.0.0.1:${port:8080}",
"SHOWCASE_DATA": "${dir:data}/objects",
"SHOWCASE_DB": "127.0.0.1:${seat:mesh-store:5432}",
"GREETING": "hello",
}
out, err := Resolution{Node: "anchor", Modules: []Manifest{processModule(env)}}.Declaration(Rendering{
Ports: map[string]map[int]int{"showcase": {8080: 21000}},
Seats: map[string]map[int]int{"mesh-store": {5432: 6852}},
})
if err != nil {
t.Fatalf("a process asking for its port and its place does not compose: %v", err)
}
setup := fileNamed(out, "showcase.setup")
if setup == nil {
t.Fatalf("the process is not in the declaration: %v", out)
}
got, _ := setup["env"].(map[string]any)
for key, want := range map[string]string{
"SHOWCASE_URL": "http://127.0.0.1:21000",
"SHOWCASE_DATA": "/var/lib/showcase/data/objects",
"SHOWCASE_DB": "127.0.0.1:6852",
"GREETING": "hello",
} {
if got[key] != want {
t.Errorf("the process is told %s=%v, want %q", key, got[key], want)
}
}
if env["SHOWCASE_URL"] != "http://127.0.0.1:${port:8080}" {
t.Fatalf("composing for one machine edited the module's own manifest: %v", env)
}
}
// An unknown reference in a process's environment is refused as a container's is, naming the
// process and the variable — left alone, it would reach the machine as a literal.
func TestAProcessAskingAboutAnUndeclaredPortIsRefused(t *testing.T) {
env := map[string]any{"SHOWCASE_URL": "http://127.0.0.1:${port:9999}"}
_, err := Resolution{Node: "anchor", Modules: []Manifest{processModule(env)}}.Declaration(Rendering{})
if err == nil {
t.Fatal("a process was told a port its module never said it listens on")
}
for _, said := range []string{"showcase-setup", "SHOWCASE_URL", "${port:9999}", "8080"} {
if !strings.Contains(err.Error(), said) {
t.Errorf("the refusal does not say %q: %v", said, err)
}
}
env = map[string]any{"SHOWCASE_DATA": "${dir:date}/objects"}
if _, err := (Resolution{Node: "anchor", Modules: []Manifest{processModule(env)}}).Declaration(Rendering{}); err == nil ||
!strings.Contains(err.Error(), "${dir:date}") {
t.Fatalf("a process naming no directory of its module was not refused: %v", err)
}
}
+5 -5
View File
@@ -43,8 +43,8 @@ import (
var ofSeat = regexp.MustCompile(`\$\{seat:([a-z0-9][a-z0-9-]*):([0-9]+)\}`)
// seatInto replaces a resource's ${seat:…} placeholders with where this machine put each seat's
// holder — in a file's content, and in a value of a container's environment. The same two places
// portInto fills, for the same reason: they are where a process reads a number from.
// holder — in a file's content, and in a value of a container's or a process's environment. The
// same places portInto fills, for the same reason: they are where a program reads a number from.
func seatInto(resource map[string]any, module string, with Rendering) error {
switch fmt.Sprint(resource["type"]) {
case "file":
@@ -58,7 +58,7 @@ func seatInto(resource map[string]any, module string, with Rendering) error {
}
resource["content"] = filled
case "container":
case "container", "process":
env, ok := resource["env"].(map[string]any)
if !ok {
return nil
@@ -78,8 +78,8 @@ func seatInto(resource map[string]any, module string, with Rendering) error {
continue
}
value, err := seatsFilledInto(written,
fmt.Sprintf("%s's container %s sets %s to something that",
module, resource["name"], key), with)
fmt.Sprintf("%s's %s %s sets %s to something that",
module, resource["type"], resource["name"], key), with)
if err != nil {
return err
}