dockerfile: remove python3 install because base img already contains

Dockerfile

@@ -1,11 +1,9 @@
-FROM debian:stable-slim
+FROM python:3.9.15-buster
 
 RUN apt-get update
 RUN apt-get install -y \
 	android-tools-adb \
 	android-tools-fastboot \
-	python3 \
-	python3-pip
 RUN pip3 install protobuf
 COPY . /magisk
 WORKDIR /magisk

README.md

@@ -1,5 +1,7 @@
 # Reinstall Magisk on Lineageos
 
+This is a fork.
+
 This little bash script is used to reinstall magisk, which gets uninstalled after each LineageOS update.
 
 Before I had to patch once more the boot using the Magisk app doing all the steps manually, making some mistakes along the way. Now it takes less than 3 minutes to reinstall magisk (virtually all the time is taken by the download), and without any intervention on my part.
@@ -15,11 +17,22 @@ Moreover it needs root privileges on your phone to run.
 
 So it may screw up both your computer and your phone, so I invite you to check its source code before running it and using it at your own risks!
 
+## Docker
+
+We use docker to make it fastly reproducible.
+Steps:
+
+1. Build <br> 
+    ```docker build  -t magiskupdate .```
+2. Run <br>
+    ```docker run --env ADB_DEVICE=<PUT YOUR ADB ADDR HERE> magiskupdate```
+
+
 ## Bash
 
 Bash is one of the standard shells on Linux and MacOS systems.
 
-If on Windows, you can use the [Windows Subsystem for Linux](https://en.wikipedia.org/wiki/Windows_Subsystem_for_Linux) to run it. See [this guide](https://docs.microsoft.com/en-us/windows/wsl/install) to install it.
+If on Windows, you should run linux.
 
 ## Installation
 

reinstall-magisk-on-lineageos

@@ -42,6 +42,15 @@ get_build_url() {
         head -1
 }
 
+check_exists_latest_lineageos_build() {
+    # The --location lets curl follow the redirection.
+    curl --location "$(get_build_url)?sha256" --output /tmp/lineageos.sha256
+    hash1=$( awk '{print $1}' lineageos.sha256 )
+    hash2=$( sha256sum lineageos.zip | awk '{print $1}' )
+    [[ "$hash1" =~ "$hash2" ]]
+    return
+}
+
 download_latest_lineageos_build() {
     # The --location lets curl follow the redirection.
     curl --location "$(get_build_url)" --output /tmp/lineageos.zip
@@ -63,10 +72,6 @@ extract_boot_image_from_file_based_ota() {
     exit 1
 }
 
-install_python_protobuf() {
-    sudo python3 -m pip install protobuf
-}
-
 extract_payload_from_payload_based_ota() {
     unzip -od /tmp /tmp/lineageos.zip payload.bin
 }
@@ -76,11 +81,10 @@ generate_random_alnum_string_of_length_6() {
 }
 
 extract_boot_image_from_payload_file() {
-    install_python_protobuf
     # For cases in which the repo has already been cloned, I prefer to create a random directory name to clone into, instead of deleting any file or directory on the user's machine.
     scripts_directory_name="scripts_$(generate_random_alnum_string_of_length_6)"
     git clone https://github.com/LineageOS/scripts /tmp/$scripts_directory_name
-    python /tmp/$scripts_directory_name/update-payload-extractor/extract.py --partitions boot --output_dir /tmp/ /tmp/payload.bin
+    python3 /tmp/$scripts_directory_name/update-payload-extractor/extract.py --partitions boot --output_dir /tmp/ /tmp/payload.bin
 }
 
 extract_boot_image_from_payload_based_ota() {
@@ -168,8 +172,12 @@ main() {
     is_rooted_debugging_enabled
     print_message "Checking on phone if Magisk is installed"
     check_magisk_app
+    if check_exists_latest_lineageos_build; then
+        print_message "Build archive already exists, skipping download"
+    else
         print_message "Downloading build archive from $(get_build_url)"
         download_latest_lineageos_build
+    fi
     print_message "Extracting 'boot.img' from build archive in /tmp/boot.img"
     extract_boot_image
     print_message "Copying from PC to phone the boot image in /sdcard/Download/boot.img"