tests: fix random

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

tests/ops/push-container/main.cue

@@ -1,4 +1,4 @@
-package testing
+package main
 
 import (
 	"dagger.io/dagger/op"

tests/ops/push-container/random.cue

@@ -1,21 +1,49 @@
-package testing
+package main
 
 import (
+	"strconv"
+
 	"dagger.io/alpine"
 	"dagger.io/dagger/op"
 )
 
-// Generate a random number
-random: {
-	string
-	#up: [
-		op.#Load & {from: alpine.#Image},
-		op.#Exec & {
-			always: true
-			args: ["sh", "-c", "cat /dev/urandom | tr -dc 'a-z' | fold -w 10 | head -n 1 | tr -d '\n' > /rand"]
-		},
-		op.#Export & {
-			source: "/rand"
-		},
-	]
+#Random: {
+	size: *12 | number
+
+	out: {
+		string
+
+		#up: [
+			op.#Load & {from: alpine.#Image & {
+				package: python3: "=~3.8"
+			}},
+
+			op.#WriteFile & {
+				dest: "/entrypoint.py"
+				content: #"""
+					import random
+					import string
+					import os
+
+					size = int(os.environ['SIZE'])
+					letters = string.ascii_lowercase
+
+					print ( ''.join(random.choice(letters) for i in range(size)) )
+					"""#
+			},
+
+			op.#Exec & {
+				always: true
+				args: ["sh", "-c", #"""
+					printf "$(python3 /entrypoint.py)" > /rand
+					"""#,
+				]
+				env: SIZE: strconv.FormatInt(size, 10)
+			},
+
+			op.#Export & {
+				source: "/rand"
+			},
+		]
+	}
 }