STRLCPY/cdebug

Improve debugger entrypoint

Get rid of job control and the sleep process

Ivan Velichko committed 2 years ago

d1759f20

1 parent c22e49b4

Total 1 files

■ ■ ■ ■ ■ ■

cmd/exec/exec.go

		skipped 96 lines
97	97		}
98	98
99	99		var (
100		-	// NOTE: Using $$ (current process PID) instead of ${SANDBOX_PID} breaks
101		-	// (at least) the nixery program - the /proc symlinks become invalid
102		-	// while chroot-ing and the operation cannot be finished (execve fails
103		-	// with ENOENT, likely because of the missing/misplaced ELF interpreter).
104		-	chrootProgramBusybox = template.Must(template.New("busybox-chroot").Parse(`
105		-	set -eumo pipefail
	100	+	chrootEntrypoint = template.Must(template.New("chroot-entrypoint").Parse(`
	101	+	set -euo pipefail
106	102
107		-	sleep 999999999 &
108		-	SANDBOX_PID=$!
	103	+	{{ if .IsNix }}
	104	+	rm -rf /proc/1/root/nix
	105	+	ln -s /proc/$$/root/nix /proc/1/root/nix
	106	+	{{ end }}
109	107
110		-	ln -s /proc/${SANDBOX_PID}/root/bin/ /proc/1/root/.cdebug-{{ .ID }}
	108	+	ln -s /proc/$$/root/bin/ /proc/1/root/.cdebug-{{ .ID }}
111	109
	110	+	cat > /.cdebug-entrypoint.sh <<EOF
	111	+	#!/bin/sh
112	112		export PATH=$PATH:/.cdebug-{{ .ID }}
113	113
114	114		chroot /proc/1/root {{ .Cmd }}
115		-	`))
116		-
117		-	chrootProgramNixery = template.Must(template.New("nixery-chroot").Parse(`
118		-	set -eumo pipefail
119		-
120		-	sleep 999999999 &
121		-	SANDBOX_PID=$!
122		-
123		-	rm -rf /proc/1/root/nix
124		-	ln -s /proc/${SANDBOX_PID}/root/nix /proc/1/root/nix
125		-
126		-	ln -s /proc/${SANDBOX_PID}/root/bin /proc/1/root/.cdebug-{{ .ID }}
	115	+	EOF
127	116
128		-	export PATH=$PATH:/.cdebug-{{ .ID }}
129		-
130		-	chroot /proc/1/root {{ .Cmd }}
	117	+	sh /.cdebug-entrypoint.sh
131	118		`))
132	119		)
133	120
		skipped 23 lines
157	144		Cmd: []string{
158	145		"sh",
159	146		"-c",
160		-	mustRenderTemplate(func() *template.Template {
161		-	if strings.Contains(opts.image, "nixery") {
162		-	return chrootProgramNixery
163		-	}
164		-	return chrootProgramBusybox
165		-	}(), map[string]string{
166		-	"ID": runID,
167		-	"Cmd": func() string {
168		-	// TODO: Use `sh -i` when -it is passed.
169		-	if len(opts.cmd) == 0 {
170		-	return "sh"
171		-	}
172		-	return "sh -c '" + strings.Join(shellescape(opts.cmd), " ") + "'"
173		-	}(),
174		-	}),
	147	+	mustRenderTemplate(
	148	+	chrootEntrypoint,
	149	+	map[string]any{
	150	+	"ID": runID,
	151	+	"IsNix": strings.Contains(opts.image, "nixery"),
	152	+	"Cmd": func() string {
	153	+	if len(opts.cmd) == 0 {
	154	+	return "sh"
	155	+	}
	156	+	return "sh -c '" + strings.Join(shellescape(opts.cmd), " ") + "'"
	157	+	}(),
	158	+	},
	159	+	),
175	160		},
176	161		Tty: opts.tty,
177	162		OpenStdin: opts.stdin,
		skipped 194 lines