1 files changed, 72 insertions, 0 deletions
diff --git a/client/go/internal/osutil/setrlimit.go b/client/go/internal/osutil/setrlimit.go
new file mode 100644
index 00000000000..6bc6d68af3e
--- /dev/null
+++ b/client/go/internal/osutil/setrlimit.go
@@ -0,0 +1,72 @@
+// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+//go:build !windows
+
+package osutil
+
+import (
+	"os"
+	"strconv"
+
+	"github.com/vespa-engine/vespa/client/go/internal/admin/trace"
+	"golang.org/x/sys/unix"
+)
+
+type ResourceId int
+
+const (
+	RLIMIT_CORE   ResourceId = unix.RLIMIT_CORE
+	RLIMIT_NOFILE ResourceId = unix.RLIMIT_NOFILE
+	RLIMIT_NPROC  ResourceId = unix.RLIMIT_NPROC
+	NO_RLIMIT     uint64     = ^uint64(0)
+)
+
+func (rid ResourceId) String() string {
+	switch rid {
+	case RLIMIT_CORE:
+		return "core file size"
+	case RLIMIT_NOFILE:
+		return "open files"
+	case RLIMIT_NPROC:
+		return "max user processes"
+	}
+	return "unknown resource id"
+}
+
+func readableLimit(val uint64) string {
+	if val == NO_RLIMIT {
+		return "unlimited"
+	}
+	return strconv.FormatUint(val, 10)
+}
+
+func SetResourceLimit(resource ResourceId, newVal uint64) {
+	trace.Debug("Wanted", newVal, "as limit for", resource.String())
+	var current unix.Rlimit
+	err := unix.Getrlimit(int(resource), &current)
+	if err != nil {
+		trace.Warning("Could not get current resource limit:", err)
+		return
+	}
+	wanted := current
+	if current.Max < newVal {
+		if os.Getuid() == 0 {
+			wanted.Max = newVal
+		} else if newVal > current.Max {
+			trace.Warning(
+				"Wanted", newVal,
+				"as limit for", resource.String(),
+				"but cannot exceed current hard limit:", current.Max)
+			newVal = current.Max
+		}
+	}
+	wanted.Cur = newVal
+	err = unix.Setrlimit(int(resource), &wanted)
+	if err != nil {
+		trace.Trace("Failed setting limit for", resource, ":", err)
+	} else {
+		trace.Debug("Resource limit", resource, "was:", readableLimit(current.Cur), "/", readableLimit(current.Max))
+		_ = unix.Getrlimit(int(resource), &current)
+		trace.Trace("Resource limit", resource, "adjusted to:", readableLimit(current.Cur), "/", readableLimit(current.Max))
+	}
+}