Initial merge of faas-containerd

This patch completes part of the work in #20 by porting the code
for faas-containerd in-tree. When tested, I was able to deploy
and then remove figlet from the store on `x86_64`.

In a follow-up PR, duplication will be removed where possible
and consolidated with updated documentation.

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

pkg/provider/config/read.go

@@ -0,0 +1,35 @@
+package config
+
+import (
+	"time"
+
+	types "github.com/openfaas/faas-provider/types"
+)
+
+type ProviderConfig struct {
+	// Sock is the address of the containerd socket
+	Sock string
+}
+
+// ReadFromEnv loads the FaaSConfig and the Containerd specific config form the env variables
+func ReadFromEnv(hasEnv types.HasEnv) (*types.FaaSConfig, *ProviderConfig, error) {
+	config, err := types.ReadConfig{}.Read(hasEnv)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	serviceTimeout := types.ParseIntOrDurationValue(hasEnv.Getenv("service_timeout"), time.Second*60)
+
+	config.EnableHealth = true
+	config.ReadTimeout = serviceTimeout
+	config.WriteTimeout = serviceTimeout
+
+	port := types.ParseIntValue(hasEnv.Getenv("port"), 8081)
+	config.TCPPort = &port
+
+	providerConfig := &ProviderConfig{
+		Sock: types.ParseString(hasEnv.Getenv("sock"), "/run/containerd/containerd.sock"),
+	}
+
+	return config, providerConfig, nil
+}