Merge pull request #1784 from twz123/new-sysinfo-probes

Some new sysinfo probes

internal/pkg/sysinfo/host_linux.go

@@ -38,11 +38,15 @@ func (s *K0sSysinfoSpec) addHostSpecificProbes(p probes.Probes) {
 		return ""
 	})
 
-	s.addKernelConfigs(linux)
+	linux.AssertProcessMaxFileDescriptors(65536)
 
 	if s.WorkerRoleEnabled {
+		probes.AssertExecutablesInPath(linux, "modprobe")
+		linux.RequireProcFS()
 		addCgroups(linux)
 	}
+
+	s.addKernelConfigs(linux)
 }
 
 func (s *K0sSysinfoSpec) addKernelConfigs(linux *linux.LinuxProbes) {

internal/pkg/sysinfo/probes/executables.go

@@ -0,0 +1,38 @@
+/*
+Copyright 2022 k0s authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package probes
+
+import (
+	"fmt"
+	"os/exec"
+)
+
+func AssertExecutablesInPath(p Probes, executables ...string) {
+	for _, executable := range executables {
+		p.Set(fmt.Sprintf("executableInPath:%s", executable), func(path ProbePath, _ Probe) Probe {
+			return ProbeFn(func(r Reporter) error {
+				desc := NewProbeDesc(fmt.Sprintf("Executable in path: %s", executable), path)
+				path, err := exec.LookPath(executable)
+				if err != nil {
+					return r.Warn(desc, ErrorProp(err), "")
+				}
+
+				return r.Pass(desc, StringProp(path))
+			})
+		})
+	}
+}

internal/pkg/sysinfo/probes/linux/procfs.go

@@ -0,0 +1,60 @@
+//go:build linux
+// +build linux
+
+/*
+Copyright 2022 k0s authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package linux
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+
+	"github.com/k0sproject/k0s/internal/pkg/sysinfo/probes"
+)
+
+func (l *LinuxProbes) RequireProcFS() {
+	l.Set("procfs", func(path probes.ProbePath, _ probes.Probe) probes.Probe {
+		return probes.ProbeFn(func(r probes.Reporter) error {
+			mountPoint := "/proc"
+			desc := probes.NewProbeDesc(fmt.Sprintf("%s file system", mountPoint), path)
+
+			var st syscall.Statfs_t
+			if err := syscall.Statfs(mountPoint, &st); err != nil {
+				if os.IsNotExist(err) {
+					return r.Reject(desc, probes.ErrorProp(err), "")
+				}
+
+				return r.Error(desc, fmt.Errorf("failed to statfs %q: %w", mountPoint, err))
+			}
+
+			if st.Type != unix.PROC_SUPER_MAGIC {
+				return r.Reject(desc, procFSType(st.Type), "unexpected file system type")
+			}
+
+			return r.Pass(desc, procFSType(st.Type))
+		})
+	})
+}
+
+type procFSType int64
+
+func (t procFSType) String() string {
+	return fmt.Sprintf("mounted (0x%x)", int64(t))
+}

internal/pkg/sysinfo/probes/linux/ulimit.go

@@ -0,0 +1,47 @@
+//go:build linux
+// +build linux
+
+/*
+Copyright 2022 k0s authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package linux
+
+import (
+	"fmt"
+	"syscall"
+
+	"github.com/k0sproject/k0s/internal/pkg/sysinfo/probes"
+)
+
+func (l *LinuxProbes) AssertProcessMaxFileDescriptors(min uint64) {
+	l.Set("RLIMIT_NOFILE", func(path probes.ProbePath, _ probes.Probe) probes.Probe {
+		return probes.ProbeFn(func(r probes.Reporter) error {
+			desc := probes.NewProbeDesc("Max. file descriptors per process", path)
+
+			var rlimit syscall.Rlimit
+			if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlimit); err != nil {
+				return r.Warn(desc, probes.ErrorProp(err), "")
+			}
+
+			prop := probes.StringProp(fmt.Sprintf("current: %d / max: %d", rlimit.Cur, rlimit.Max))
+			if rlimit.Cur < min {
+				return r.Warn(desc, prop, fmt.Sprintf("< %d", min))
+			}
+
+			return r.Pass(desc, prop)
+		})
+	})
+}

internal/pkg/sysinfo/probes/probes.go

@@ -74,6 +74,21 @@ type ProbedProp interface {
 	String() string
 }
 
+// StringProp is a convenience way of reporting an arbitrary string as a probed property.
+type StringProp string
+
+func (s StringProp) String() string {
+	return string(s)
+}
+
+// ErrorProp is a convenience way of reporting an arbitrary error as a probed property.
+func ErrorProp(err error) interface {
+	ProbedProp
+	error
+} {
+	return errorProp{err}
+}
+
 // Reporter receives the outcome of probes.
 type Reporter interface {
 	// Pass informs about a probe that passed.
@@ -115,6 +130,16 @@ type probeDesc struct {
 func (d *probeDesc) Path() ProbePath     { return d.path }
 func (d *probeDesc) DisplayName() string { return d.name }
 
+type errorProp struct{ error }
+
+func (e errorProp) String() string {
+	return e.Error()
+}
+
+func (e errorProp) Unwrap() error {
+	return e.error
+}
+
 type probes struct {
 	path   ProbePath
 	probes []*containedProbe