Files
mesh-catalog/modules/ssh-client/cmd/ssh-client-tools/runner.go
T
jochen dde9c264f5 ssh-client: the mesh's region first in ~/.ssh/config, its hosts in config.d, tools in Go
The region at the end let earlier Host lines win over the mesh's (research 027/03). A
roster fact cannot be placed at the start, so the region holds one Include of config.d,
and the hosts are config.d/00-mesh, read first. Eight tools; authorized_keys and
known_hosts stay found until the controller holds those facts.
2026-10-04 12:38:40 +02:00

62 lines
1.7 KiB
Go

package main
import (
"bytes"
"context"
"errors"
"fmt"
"os"
"os/exec"
"strings"
"time"
)
// Ran is what a command did: its output, its exit status, and why it never ran to an answer.
type Ran struct {
Stdout string
Stderr string
Status int
// Err is "ENOENT" when the program is not installed, or says it was ended for taking too long.
Err string
}
// Runner runs one command with extra environment words, so every tool can be tested without ssh.
type Runner func(ctx context.Context, env []string, name string, args ...string) Ran
// CallTimeout bounds one command: below the runtime's thirty-second call limit.
const CallTimeout = 20 * time.Second
// ExecRunner runs a command on this machine, with no terminal and nothing on its stdin, bounded by
// CallTimeout.
func ExecRunner(ctx context.Context, env []string, name string, args ...string) Ran {
ctx, cancel := context.WithTimeout(ctx, CallTimeout)
defer cancel()
cmd := exec.CommandContext(ctx, name, args...)
cmd.Env = append(os.Environ(), env...)
var out, errb bytes.Buffer
cmd.Stdout, cmd.Stderr = &out, &errb
err := cmd.Run()
r := Ran{Stdout: out.String(), Stderr: errb.String()}
var exitErr *exec.ExitError
switch {
case errors.Is(ctx.Err(), context.DeadlineExceeded):
r.Status, r.Err = 124, fmt.Sprintf("no answer within %d s", int(CallTimeout/time.Second))
case errors.Is(err, exec.ErrNotFound):
r.Status, r.Err = 127, "ENOENT"
case errors.As(err, &exitErr):
r.Status = exitErr.ExitCode()
case err != nil:
r.Status, r.Err = 1, err.Error()
}
return r
}
func firstLine(s string) string {
for _, l := range strings.Split(s, "\n") {
if l = strings.TrimSpace(l); l != "" {
return l
}
}
return ""
}