Add log shim and collect command

The collect command redirects function logs to the journal for
viewing on journalctl. faas-cli logs is not implemented as of
yet. View logs with journalctl -t openfaas-fn:FN_NAME_HERE.

Tested on Dell XPS with Ubuntu Linux. The approach takes
inspiration from the Stellar project.

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

README.md

@@ -75,6 +75,19 @@ ofc-bootstrap registry-login --username <your-registry-username> --password-stdi
 ```
 The file will be created in `./credentials/`
 
+### Logs for functions
+
+You can view the logs of functions using `journalctl`:
+
+```bash
+journalctl -t openfaas-fn:FUNCTION_NAME
+
+
+faas-cli store deploy figlet
+journalctl -t openfaas-fn:figlet -f &
+echo logs | faas-cli invoke figlet
+```
+
 ### Manual / developer instructions
 
 See [here for manual / developer instructions](docs/DEV.md)

cmd/collect.go

@@ -12,6 +12,10 @@ import (
 	"github.com/spf13/cobra"
 )
 
+func CollectCommand() *cobra.Command {
+	return collectCmd
+}
+
 var collectCmd = &cobra.Command{
 	Use:   "collect",
 	Short: "Collect logs to the journal",

cmd/root.go

@@ -18,6 +18,10 @@ func init() {
 	rootCommand.AddCommand(collectCmd)
 }
 
+func RootCommand() *cobra.Command {
+	return rootCommand
+}
+
 var (
 	// GitCommit Git Commit SHA
 	GitCommit string

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"os"
 
 	"github.com/openfaas/faasd/cmd"
@@ -15,6 +16,21 @@ var (
 )
 
 func main() {
+
+	if _, ok := os.LookupEnv("CONTAINER_ID"); ok {
+		collect := cmd.RootCommand()
+		collect.SetArgs([]string{"collect"})
+		collect.SilenceUsage = true
+		collect.SilenceErrors = true
+
+		err := collect.Execute()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, err.Error())
+			os.Exit(1)
+		}
+		os.Exit(0)
+	}
+
 	if err := cmd.Execute(Version, GitCommit); err != nil {
 		os.Exit(1)
 	}

pkg/provider/handlers/deploy.go

@@ -120,7 +120,10 @@ func deploy(ctx context.Context, req types.FunctionDeployment, client *container
 func createTask(ctx context.Context, client *containerd.Client, container containerd.Container, cni gocni.CNI) error {
 
 	name := container.ID()
-	task, taskErr := container.NewTask(ctx, cio.NewCreator(cio.WithStdio))
+	// task, taskErr := container.NewTask(ctx, cio.NewCreator(cio.WithStdio))
+
+	task, taskErr := container.NewTask(ctx, cio.BinaryIO("/usr/local/bin/faasd", nil))
+
 	if taskErr != nil {
 		return fmt.Errorf("unable to start task: %s, error: %s", name, taskErr)
 	}