Upgrades to containerd, fix deprecations upstream

* Fixes upstream deprecations for containerd
* Fixes deprecations in ioutil package usage
* Break out separate files for function handlers
* Upgrades containerd to 1.7.22
* Fixes default namespace functionality
* Pre-deploy checks as per license agreement
* Removes extra log messages for payload in HTTP handlers, you
can enable FAAS_DEBUG=1 in the CLI instead to see this from
the client's perspective
* Add additional Google DNS server 8.8.4.4 for functions

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

vendor/github.com/containerd/platforms/cpuinfo_linux.go

@@ -0,0 +1,160 @@
+/*
+   Copyright The containerd 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 platforms
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+	"runtime"
+	"strings"
+
+	"golang.org/x/sys/unix"
+)
+
+// getMachineArch retrieves the machine architecture through system call
+func getMachineArch() (string, error) {
+	var uname unix.Utsname
+	err := unix.Uname(&uname)
+	if err != nil {
+		return "", err
+	}
+
+	arch := string(uname.Machine[:bytes.IndexByte(uname.Machine[:], 0)])
+
+	return arch, nil
+}
+
+// For Linux, the kernel has already detected the ABI, ISA and Features.
+// So we don't need to access the ARM registers to detect platform information
+// by ourselves. We can just parse these information from /proc/cpuinfo
+func getCPUInfo(pattern string) (info string, err error) {
+
+	cpuinfo, err := os.Open("/proc/cpuinfo")
+	if err != nil {
+		return "", err
+	}
+	defer cpuinfo.Close()
+
+	// Start to Parse the Cpuinfo line by line. For SMP SoC, we parse
+	// the first core is enough.
+	scanner := bufio.NewScanner(cpuinfo)
+	for scanner.Scan() {
+		newline := scanner.Text()
+		list := strings.Split(newline, ":")
+
+		if len(list) > 1 && strings.EqualFold(strings.TrimSpace(list[0]), pattern) {
+			return strings.TrimSpace(list[1]), nil
+		}
+	}
+
+	// Check whether the scanner encountered errors
+	err = scanner.Err()
+	if err != nil {
+		return "", err
+	}
+
+	return "", fmt.Errorf("getCPUInfo for pattern %s: %w", pattern, errNotFound)
+}
+
+// getCPUVariantFromArch get CPU variant from arch through a system call
+func getCPUVariantFromArch(arch string) (string, error) {
+
+	var variant string
+
+	arch = strings.ToLower(arch)
+
+	if arch == "aarch64" {
+		variant = "8"
+	} else if arch[0:4] == "armv" && len(arch) >= 5 {
+		// Valid arch format is in form of armvXx
+		switch arch[3:5] {
+		case "v8":
+			variant = "8"
+		case "v7":
+			variant = "7"
+		case "v6":
+			variant = "6"
+		case "v5":
+			variant = "5"
+		case "v4":
+			variant = "4"
+		case "v3":
+			variant = "3"
+		default:
+			variant = "unknown"
+		}
+	} else {
+		return "", fmt.Errorf("getCPUVariantFromArch invalid arch: %s, %w", arch, errInvalidArgument)
+	}
+	return variant, nil
+}
+
+// getCPUVariant returns cpu variant for ARM
+// We first try reading "Cpu architecture" field from /proc/cpuinfo
+// If we can't find it, then fall back using a system call
+// This is to cover running ARM in emulated environment on x86 host as this field in /proc/cpuinfo
+// was not present.
+func getCPUVariant() (string, error) {
+	variant, err := getCPUInfo("Cpu architecture")
+	if err != nil {
+		if errors.Is(err, errNotFound) {
+			// Let's try getting CPU variant from machine architecture
+			arch, err := getMachineArch()
+			if err != nil {
+				return "", fmt.Errorf("failure getting machine architecture: %v", err)
+			}
+
+			variant, err = getCPUVariantFromArch(arch)
+			if err != nil {
+				return "", fmt.Errorf("failure getting CPU variant from machine architecture: %v", err)
+			}
+		} else {
+			return "", fmt.Errorf("failure getting CPU variant: %v", err)
+		}
+	}
+
+	// handle edge case for Raspberry Pi ARMv6 devices (which due to a kernel quirk, report "CPU architecture: 7")
+	// https://www.raspberrypi.org/forums/viewtopic.php?t=12614
+	if runtime.GOARCH == "arm" && variant == "7" {
+		model, err := getCPUInfo("model name")
+		if err == nil && strings.HasPrefix(strings.ToLower(model), "armv6-compatible") {
+			variant = "6"
+		}
+	}
+
+	switch strings.ToLower(variant) {
+	case "8", "aarch64":
+		variant = "v8"
+	case "7", "7m", "?(12)", "?(13)", "?(14)", "?(15)", "?(16)", "?(17)":
+		variant = "v7"
+	case "6", "6tej":
+		variant = "v6"
+	case "5", "5t", "5te", "5tej":
+		variant = "v5"
+	case "4", "4t":
+		variant = "v4"
+	case "3":
+		variant = "v3"
+	default:
+		variant = "unknown"
+	}
+
+	return variant, nil
+}