Prevent installation of apps for arm

Certain apps cannot be installed on ARM, why? Because the
authors do not provide support.

k3sup is not about ARM, it's about being able to install any
compatible app to any compatible Kubernetes cluster, with
Intel aka PC aka "normal computers" being the default target
of most cloud software.

cc @pisymbol

Fixes: #198

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

README.md

@@ -122,10 +122,12 @@ kubectl get node
 
 ### 🎬 Install an `app` with `k3sup`
 
-Install apps with `k3sup` `>=0.4.0` directly into any Kubernetes cluster, all you need is `kubectl` access.
+Install apps with `k3sup` `>=0.4.0` directly **into any Kubernetes cluster**, all you need is `kubectl` access.
 
 You can install [openfaas](https://github.com/openfaas/faas) for Kubernetes in a single command, it will detect whether you're using a Raspberry Pi or a regular computer.
 
+> What does "PC" only mean? It means that you cannot install the app to a computer running an ARM processor. For instance, Istio has no support for ARM, only Intel aka PC.
+
 ```sh
 # OpenFaaS - microservices and functions for Kubernetes
 # PC, RPi and ARM64
@@ -150,8 +152,8 @@ k3sup app install cert-manager
 # PC, RPi and ARM64
 k3sup app install nginx-ingress
 
-# docker-registry - host your own registry
-k3sup app install docker-registry
+# PC only
+k3sup app install istio
 
 # docker-registry-ingress - add TLS to your registry and ingress on port 443 and 80
 k3sup app install docker-registry-ingress --email example@example.com --domain reg.example.com
@@ -166,10 +168,9 @@ k3sup app install APP_NAME --help
 ```
 
 Apps that you can install today:
-* openfaas
+* `openfaas` / `openfaas-ingress`
 * nginx-ingress
 * cert-manager
-* openfaas-ingress
 * inlets-operator
 * metrics-server
 * tiller
@@ -181,7 +182,7 @@ Apps that you can install today:
 * kubernetes-dashboard
 * istio
 * crossplane
-* docker-registry
+* `docker-registry` / `docker-registry-ingress`
 
 Want to request an app? [Raise an issue](https://github.com/alexellis/k3sup/issues) or let me know on [Slack](https://slack.openfaas.io).
 

cmd/apps/istio_app.go

@@ -14,6 +14,8 @@ import (
 	"github.com/spf13/cobra"
 )
 
+var IntelArch = "amd64"
+
 func MakeInstallIstio() *cobra.Command {
 	var istio = &cobra.Command{
 		Use:          "istio",
@@ -47,6 +49,10 @@ func MakeInstallIstio() *cobra.Command {
 		arch := getNodeArchitecture()
 		fmt.Printf("Node architecture: %q\n", arch)
 
+		if arch != IntelArch {
+			return fmt.Errorf(`only Intel, i.e. PC architecture is supported for this app`)
+		}
+
 		userPath, err := config.InitUserDir()
 		if err != nil {
 			return err
@@ -212,4 +218,4 @@ global:
 
 	writeTo := path.Join(os.TempDir(), "istio-values.yaml")
 	return writeTo, ioutil.WriteFile(writeTo, []byte(out), 0600)
-}
+}

cmd/apps/kafkaconnector_app.go

@@ -108,6 +108,9 @@ func MakeInstallKafkaConnector() *cobra.Command {
 
 		arch := getNodeArchitecture()
 		fmt.Printf("Node architecture: %q\n", arch)
+		if arch != IntelArch {
+			return fmt.Errorf(`only Intel, i.e. PC architecture is supported for this app`)
+		}
 
 		fmt.Println("Chart path: ", chartPath)
 
@@ -139,7 +142,6 @@ func MakeInstallKafkaConnector() *cobra.Command {
 	return command
 }
 
-
 const KafkaConnectorInfoMsg = `# View the connector's logs:
 
 kubectl logs deploy/kafka-connector -n openfaas -f
@@ -151,4 +153,4 @@ kubectl logs deploy/kafka-connector -n openfaas -f
 const kafkaConnectorInstallMsg = `=======================================================================
 = kafka-connector has been installed.                                   =
 =======================================================================` +
-	"\n\n" + KafkaConnectorInfoMsg + "\n\n" + pkg.ThanksForUsing
+	"\n\n" + KafkaConnectorInfoMsg + "\n\n" + pkg.ThanksForUsing

cmd/apps/kubernetes_exec.go

@@ -200,7 +200,7 @@ func kubectlTask(parts ...string) (execute.ExecResult, error) {
 	task := execute.ExecTask{
 		Command:     "kubectl",
 		Args:        parts,
-		StreamStdio: true,
+		StreamStdio: false,
 	}
 
 	res, err := task.Execute()

cmd/apps/linkerd_app.go

@@ -38,8 +38,12 @@ func MakeInstallLinkerd() *cobra.Command {
 			kubeConfigPath, _ = command.Flags().GetString("kubeconfig")
 		}
 		fmt.Printf("Using kubeconfig: %s\n", kubeConfigPath)
+
 		arch := getNodeArchitecture()
 		fmt.Printf("Node architecture: %q\n", arch)
+		if arch != IntelArch {
+			return fmt.Errorf(`only Intel, i.e. PC architecture is supported for this app`)
+		}
 
 		userPath, err := getUserPath()
 		if err != nil {
@@ -189,4 +193,4 @@ linkerd --help`
 var linkerdInstallMsg = `=======================================================================
 = Linkerd has been installed.                                         =
 =======================================================================` +
-	"\n\n" + LinkerdInfoMsg + "\n\n" + pkg.ThanksForUsing
+	"\n\n" + LinkerdInfoMsg + "\n\n" + pkg.ThanksForUsing

cmd/apps/tiller_app.go

@@ -34,8 +34,8 @@ func MakeInstallTiller() *cobra.Command {
 		arch := getNodeArchitecture()
 		fmt.Printf("Node architecture: %q\n", arch)
 
-		if arch != "x86_64" && arch != "amd64" {
-			return fmt.Errorf("This app is not known to work with the %s architecture", arch)
+		if arch != IntelArch {
+			return fmt.Errorf(`only Intel, i.e. PC architecture is supported for this app`)
 		}
 
 		userPath, err := getUserPath()
@@ -106,4 +106,4 @@ var TillerInfoMsg = `# You can now use helm with tiller from the installation di
 var tillerInstallMsg = `=======================================================================
 = tiller has been installed.                   	                      =
 =======================================================================` +
-	"\n\n" + TillerInfoMsg + "\n\n" + pkg.ThanksForUsing
+	"\n\n" + TillerInfoMsg + "\n\n" + pkg.ThanksForUsing