From f93ba744038d79211a48105bd691e26e1770cc61 Mon Sep 17 00:00:00 2001
From: Tom Clegg <tom@curii.com>
Date: Thu, 14 Apr 2022 02:32:09 -0400
Subject: [PATCH] 18992: Fix abrupt exit on cgroup test failure.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@curii.com>
---
 lib/crunchrun/cgroup.go      | 11 +++++------
 lib/crunchrun/cgroup_test.go |  6 ++++--
 lib/crunchrun/crunchrun.go   |  6 +++++-
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/lib/crunchrun/cgroup.go b/lib/crunchrun/cgroup.go
index 0b254f5bd7..48ec93b876 100644
--- a/lib/crunchrun/cgroup.go
+++ b/lib/crunchrun/cgroup.go
@@ -6,16 +6,16 @@ package crunchrun
 
 import (
 	"bytes"
+	"fmt"
 	"io/ioutil"
-	"log"
 )
 
 // Return the current process's cgroup for the given subsystem.
-func findCgroup(subsystem string) string {
+func findCgroup(subsystem string) (string, error) {
 	subsys := []byte(subsystem)
 	cgroups, err := ioutil.ReadFile("/proc/self/cgroup")
 	if err != nil {
-		log.Fatal(err)
+		return "", err
 	}
 	for _, line := range bytes.Split(cgroups, []byte("\n")) {
 		toks := bytes.SplitN(line, []byte(":"), 4)
@@ -24,10 +24,9 @@ func findCgroup(subsystem string) string {
 		}
 		for _, s := range bytes.Split(toks[1], []byte(",")) {
 			if bytes.Compare(s, subsys) == 0 {
-				return string(toks[2])
+				return string(toks[2]), nil
 			}
 		}
 	}
-	log.Fatalf("subsystem %q not found in /proc/self/cgroup", subsystem)
-	return ""
+	return "", fmt.Errorf("subsystem %q not found in /proc/self/cgroup", subsystem)
 }
diff --git a/lib/crunchrun/cgroup_test.go b/lib/crunchrun/cgroup_test.go
index b43479a3b4..eb87456d14 100644
--- a/lib/crunchrun/cgroup_test.go
+++ b/lib/crunchrun/cgroup_test.go
@@ -14,8 +14,10 @@ var _ = Suite(&CgroupSuite{})
 
 func (s *CgroupSuite) TestFindCgroup(c *C) {
 	for _, s := range []string{"devices", "cpu", "cpuset"} {
-		g := findCgroup(s)
-		c.Check(g, Not(Equals), "")
+		g, err := findCgroup(s)
+		if c.Check(err, IsNil) {
+			c.Check(g, Not(Equals), "", Commentf("subsys %q", s))
+		}
 		c.Logf("cgroup(%q) == %q", s, g)
 	}
 }
diff --git a/lib/crunchrun/crunchrun.go b/lib/crunchrun/crunchrun.go
index 84b153554a..219ed3b98d 100644
--- a/lib/crunchrun/crunchrun.go
+++ b/lib/crunchrun/crunchrun.go
@@ -1926,7 +1926,11 @@ func (command) RunCommand(prog string, args []string, stdin io.Reader, stdout, s
 	cr.enableNetwork = *enableNetwork
 	cr.networkMode = *networkMode
 	if *cgroupParentSubsystem != "" {
-		p := findCgroup(*cgroupParentSubsystem)
+		p, err := findCgroup(*cgroupParentSubsystem)
+		if err != nil {
+			log.Printf("fatal: cgroup parent subsystem: %s", err)
+			return 1
+		}
 		cr.setCgroupParent = p
 		cr.expectCgroupParent = p
 	}
-- 
2.30.2