[local-preview] Warn and Confirm from user before proceeding

Currently, For Users with ARM CPU's, `local-preview` does not
really work and its hard for the script to know as it runs inside
docker (which could be a x86 VM).

This Updates the script to warn the users on the requirements before
starting and running `local-preview`.

Signed-off-by: Tarun Pothulapati <[email protected]>

install/preview/entrypoint.sh

@@ -4,6 +4,8 @@
 
 set -e
 
+touch logs.txt
+
 # Set Domain to `preview.gitpod-self-hosted.com` if not set
 if [ -z "${DOMAIN}" ]; then
   export DOMAIN="preview.gitpod-self-hosted.com"
@@ -14,7 +16,8 @@ USER_ID="$(od -x /dev/urandom | head -1 | awk '{OFS="-"; print $2$3,$4,$5,$6,$7$
 export USER_ID
 
 if [ "$1" != "logging" ]; then
-  $0 logging 2>&1 | /prettylog
+  $0 logging > logs.txt 2>&1 &
+  /prettylog
   exit
 fi
 

install/preview/prettylog/go.mod

@@ -3,19 +3,27 @@ module github.com/gitpod-io/gitpod/install/preview/prettylog
 go 1.18
 
 require (
-	github.com/atomicgo/cursor v0.0.1 // indirect
 	github.com/gookit/color v1.5.0 // indirect
+	github.com/hpcloud/tail v1.0.0
 	github.com/mattn/go-runewidth v0.0.13 // indirect
-	github.com/pterm/pterm v0.12.41
+	github.com/pterm/pterm v0.12.42
 	github.com/rivo/uniseg v0.2.0 // indirect
 	github.com/xo/terminfo v0.0.0-20210125001918-ca9a967f8778 // indirect
-	golang.org/x/sys v0.0.0-20220319134239-a9b59b0215f8 // indirect
+	golang.org/x/sys v0.0.0-20220412211240-33da011f77ad // indirect
 	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 // indirect
 	gopkg.in/segmentio/analytics-go.v3 v3.1.0
 )
 
 require (
+	atomicgo.dev/cursor v0.1.1 // indirect
+	atomicgo.dev/keyboard v0.2.8 // indirect
 	github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869 // indirect
+	github.com/containerd/console v1.0.3 // indirect
+	github.com/fsnotify/fsnotify v1.5.4 // indirect
+	github.com/lithammer/fuzzysearch v1.1.5 // indirect
 	github.com/segmentio/backo-go v1.0.1 // indirect
 	github.com/xtgo/uuid v0.0.0-20140804021211-a0b114877d4c // indirect
+	golang.org/x/text v0.3.7 // indirect
+	gopkg.in/fsnotify.v1 v1.4.7 // indirect
+	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 // indirect
 )

install/preview/prettylog/main.go

@@ -4,13 +4,14 @@
 package main
 
 import (
-	"bufio"
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"os"
 	"strings"
 
+	"github.com/hpcloud/tail"
 	"github.com/pterm/pterm"
 	"gopkg.in/segmentio/analytics-go.v3"
 )
@@ -38,21 +39,31 @@ var (
 )
 
 func main() {
-	dmp, err := os.OpenFile("logs.txt", os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0644)
-	if err != nil {
-		panic(err)
+	// Warn and wait for user approval
+	pterm.FgLightCyan.Println(`
+Welcome to the local preview of Gitpod. Please note the following limitations:
+  - Performance is limited by the capabilities of your machine - a minimum of 4 cores and 6GB of RAM are required
+  - ARM CPUs including Macs with Apple Silicon (e.g. M1) are currently not supported
+For more information about these limitation, please visit the local preview documentation: https://www.gitpod.io/docs/self-hosted/latest/local-preview`)
+
+	result, _ := pterm.DefaultInteractiveConfirm.WithDefaultText("Continue?").WithDefaultValue(true).Show()
+	if !result {
+		// send telemetry for user exit
+		send_telemetry("user exit")
+		return
 	}
-	defer dmp.Close()
 
-	r := io.TeeReader(os.Stdin, dmp)
+	file, err := tail.TailFile("logs.txt", tail.Config{Follow: true})
+	if err != nil {
+		log.Fatal(err)
+	}
 
-	scan := bufio.NewScanner(r)
 	var msgIdx int
 	lastSpinner, _ := pterm.DefaultSpinner.Start(msgs[msgIdx].Msg)
 	// send Telemetry update for the first phase
 	send_telemetry(msgs[msgIdx].Status)
-	for scan.Scan() {
-		line := scan.Text()
+	for tailLine := range file.Lines {
+		line := tailLine.Text
 		msg := msgs[msgIdx]
 		var next bool
 		switch {
@@ -77,7 +88,7 @@ func main() {
 		send_telemetry(msgs[msgIdx].Status)
 
 	}
-	err = scan.Err()
+	err = file.Err()
 	if errors.Is(err, io.EOF) {
 		err = nil
 	}