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/defaults_windows.go

@@ -0,0 +1,118 @@
+/*
+   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 (
+	"fmt"
+	"runtime"
+	"strconv"
+	"strings"
+
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
+	"golang.org/x/sys/windows"
+)
+
+// DefaultSpec returns the current platform's default platform specification.
+func DefaultSpec() specs.Platform {
+	major, minor, build := windows.RtlGetNtVersionNumbers()
+	return specs.Platform{
+		OS:           runtime.GOOS,
+		Architecture: runtime.GOARCH,
+		OSVersion:    fmt.Sprintf("%d.%d.%d", major, minor, build),
+		// The Variant field will be empty if arch != ARM.
+		Variant: cpuVariant(),
+	}
+}
+
+type windowsmatcher struct {
+	specs.Platform
+	osVersionPrefix string
+	defaultMatcher  Matcher
+}
+
+// Match matches platform with the same windows major, minor
+// and build version.
+func (m windowsmatcher) Match(p specs.Platform) bool {
+	match := m.defaultMatcher.Match(p)
+
+	if match && m.OS == "windows" {
+		// HPC containers do not have OS version filled
+		if m.OSVersion == "" || p.OSVersion == "" {
+			return true
+		}
+
+		hostOsVersion := getOSVersion(m.osVersionPrefix)
+		ctrOsVersion := getOSVersion(p.OSVersion)
+		return checkHostAndContainerCompat(hostOsVersion, ctrOsVersion)
+	}
+
+	return match
+}
+
+func getOSVersion(osVersionPrefix string) osVersion {
+	parts := strings.Split(osVersionPrefix, ".")
+	if len(parts) < 3 {
+		return osVersion{}
+	}
+
+	majorVersion, _ := strconv.Atoi(parts[0])
+	minorVersion, _ := strconv.Atoi(parts[1])
+	buildNumber, _ := strconv.Atoi(parts[2])
+
+	return osVersion{
+		MajorVersion: uint8(majorVersion),
+		MinorVersion: uint8(minorVersion),
+		Build:        uint16(buildNumber),
+	}
+}
+
+// Less sorts matched platforms in front of other platforms.
+// For matched platforms, it puts platforms with larger revision
+// number in front.
+func (m windowsmatcher) Less(p1, p2 specs.Platform) bool {
+	m1, m2 := m.Match(p1), m.Match(p2)
+	if m1 && m2 {
+		r1, r2 := revision(p1.OSVersion), revision(p2.OSVersion)
+		return r1 > r2
+	}
+	return m1 && !m2
+}
+
+func revision(v string) int {
+	parts := strings.Split(v, ".")
+	if len(parts) < 4 {
+		return 0
+	}
+	r, err := strconv.Atoi(parts[3])
+	if err != nil {
+		return 0
+	}
+	return r
+}
+
+func prefix(v string) string {
+	parts := strings.Split(v, ".")
+	if len(parts) < 4 {
+		return v
+	}
+	return strings.Join(parts[0:3], ".")
+}
+
+// Default returns the current platform's default platform specification.
+func Default() MatchComparer {
+	return Only(DefaultSpec())
+}