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>

pkg/provider/handlers/function_get.go

@@ -0,0 +1,150 @@
+package handlers
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"strings"
+
+	"github.com/opencontainers/runtime-spec/specs-go"
+
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/namespaces"
+	"github.com/openfaas/faasd/pkg/cninetwork"
+)
+
+// GetFunction returns a function that matches name
+func GetFunction(client *containerd.Client, name string, namespace string) (Function, error) {
+	ctx := namespaces.WithNamespace(context.Background(), namespace)
+	fn := Function{}
+
+	c, err := client.LoadContainer(ctx, name)
+	if err != nil {
+		return Function{}, fmt.Errorf("unable to find function: %s, error %w", name, err)
+	}
+
+	image, err := c.Image(ctx)
+	if err != nil {
+		return fn, err
+	}
+
+	containerName := c.ID()
+	allLabels, labelErr := c.Labels(ctx)
+
+	if labelErr != nil {
+		log.Printf("cannot list container %s labels: %s", containerName, labelErr)
+	}
+
+	labels, annotations := buildLabelsAndAnnotations(allLabels)
+
+	spec, err := c.Spec(ctx)
+	if err != nil {
+		return Function{}, fmt.Errorf("unable to load function %s error: %w", name, err)
+	}
+
+	info, err := c.Info(ctx)
+	if err != nil {
+		return Function{}, fmt.Errorf("can't load info for: %s, error %w", name, err)
+	}
+
+	envVars, envProcess := readEnvFromProcessEnv(spec.Process.Env)
+	secrets := readSecretsFromMounts(spec.Mounts)
+
+	fn.name = containerName
+	fn.namespace = namespace
+	fn.image = image.Name()
+	fn.labels = labels
+	fn.annotations = annotations
+	fn.secrets = secrets
+	fn.envVars = envVars
+	fn.envProcess = envProcess
+	fn.createdAt = info.CreatedAt
+	fn.memoryLimit = readMemoryLimitFromSpec(spec)
+
+	replicas := 0
+	task, err := c.Task(ctx, nil)
+	if err == nil {
+		// Task for container exists
+		svc, err := task.Status(ctx)
+		if err != nil {
+			return Function{}, fmt.Errorf("unable to get task status for container: %s %w", name, err)
+		}
+
+		if svc.Status == "running" {
+			replicas = 1
+			fn.pid = task.Pid()
+
+			// Get container IP address
+			ip, err := cninetwork.GetIPAddress(name, task.Pid())
+			if err != nil {
+				return Function{}, err
+			}
+			fn.IP = ip
+		}
+	} else {
+		replicas = 0
+	}
+
+	fn.replicas = replicas
+	return fn, nil
+}
+
+func readEnvFromProcessEnv(env []string) (map[string]string, string) {
+	foundEnv := make(map[string]string)
+	fprocess := ""
+	for _, e := range env {
+		kv := strings.Split(e, "=")
+		if len(kv) == 1 {
+			continue
+		}
+
+		if kv[0] == "PATH" {
+			continue
+		}
+
+		if kv[0] == "fprocess" {
+			fprocess = kv[1]
+			continue
+		}
+
+		foundEnv[kv[0]] = kv[1]
+	}
+
+	return foundEnv, fprocess
+}
+
+func readSecretsFromMounts(mounts []specs.Mount) []string {
+	secrets := []string{}
+	for _, mnt := range mounts {
+		x := strings.Split(mnt.Destination, "/var/openfaas/secrets/")
+		if len(x) > 1 {
+			secrets = append(secrets, x[1])
+		}
+
+	}
+	return secrets
+}
+
+// buildLabelsAndAnnotations returns a separated list with labels first,
+// followed by annotations by checking each key of ctrLabels for a prefix.
+func buildLabelsAndAnnotations(ctrLabels map[string]string) (map[string]string, map[string]string) {
+	labels := make(map[string]string)
+	annotations := make(map[string]string)
+
+	for k, v := range ctrLabels {
+		if strings.HasPrefix(k, annotationLabelPrefix) {
+			annotations[strings.TrimPrefix(k, annotationLabelPrefix)] = v
+		} else {
+			labels[k] = v
+		}
+	}
+
+	return labels, annotations
+}
+
+func readMemoryLimitFromSpec(spec *specs.Spec) int64 {
+	if spec.Linux == nil || spec.Linux.Resources == nil || spec.Linux.Resources.Memory == nil || spec.Linux.Resources.Memory.Limit == nil {
+		return 0
+	}
+	return *spec.Linux.Resources.Memory.Limit
+}