Building Apps and Getting Notified

mkdir shell-scripts

fdroid:~$ ls -1

fdroiddata
fdroidserver
shell-scripts

#!/bin/sh

# Based on F-Droid's guide at https://f-droid.org/en/docs/Submitting_to_F-Droid_Quick_Start_Guide/

# The only amendment to this script from the above URL are:
# - Mount an additional volume, the `shell-scripts` directory (parent directory of this script and `fdroid-prepare-env.sh`)
# - Change the entry point to `fdroid-prepare-env.sh`
# - Pass a couple of environment variables, IDs to be used to interact with Telegram so we can get a message pushed when a process finishes

# Explanation of command:
# `run`		creates a container from the image (image is given as final argument to the command)
# --rm 		when the container is exited, automatically remove it (the container, not the image)
# -i		`--interactive`, meaning you will be put into a `/bin/bash` (from the later command) session in the container
# -t		`--tty` container output gets sent to a virtual tty, meaning it will be formatted nicely and behave in specific expected ways
# -u		`--user` so in this case we are running as user 'vagrant'
# --entrypoint	overrides the default ENTRYPOINT of the image
# -v		mount a volume, the arg:arg format mounts a local (1st arg) volume inside the container at (2nd arg)
# 		:z at the end means Docker labels the content with a shared content label. Shared volume labels allow all containers to read/write content
# 		:Z at the end means Docker to label the content with a private unshared label. Only the current container can use a private volume
# -e		environment variable to be passed
# [final arg]	the image from which the container will be created

# Notes on setting up credentials for Telegram bot
# Based on tips from https://www.techrepublic.com/article/how-to-safely-store-passwords-linux-server/
# sudo apk add pass gnupg gnupg2 pinentry-tty
# gpg2 --full-generate-key
# pass init m@mm-dev.rocks
# pass insert telegrambot/botid
# pass insert telegrambot/chatid
# gpg-connect-agent reloadagent /bye

sudo docker run --rm -itu vagrant --entrypoint /home/vagrant/shell-scripts/fdroid-prepare-env.sh \
  -v ~/fdroiddata:/build:z \
  -v ~/fdroidserver:/home/vagrant/fdroidserver:Z \
  -v ~/shell-scripts:/home/vagrant/shell-scripts:Z \
  -e TELEGRAM_BOTID="$(pass telegrambot/botid)" \
  -e TELEGRAM_CHATID="$(pass telegrambot/chatid)" \
  registry.gitlab.com/fdroid/fdroidserver:buildserver

#!/bin/bash

# #################################
#
# F-Droid build tools helper script
#
# #################################
#
# Docker image housekeeping, stuff to be done whenever the F-Droid container is creaated.
# Based on F-Droid's guide at https://f-droid.org/en/docs/Submitting_to_F-Droid_Quick_Start_Guide/
#
# - Several commands need to be run inside the container every time it starts, meaning constandly having to refer to the above URL
# - Instead, now this script is passed as the entry point to `docker run`
# - Alongside the F-Droid recommendations, export a function `send_tg_alert`, which allows a Telegram message to be sent when a command has completed execution


# Bring in system-wide settings and add some environment variables
# #################################
. /etc/profile
export PATH="$fdroidserver:$PATH" PYTHONPATH="$fdroidserver"
export JAVA_HOME=$(java -XshowSettings:properties -version 2>&1 > /dev/null | grep 'java.home' | awk -F'=' '{print $2}' | tr -d ' ')


# Create the message text to be sent to Telegram
# #################################
#
# - The message contains the shell command (from history) last entered (ie the command that was run and we are informing the recipient about)
# - Use MarkdownV2 syntax, see notes at https://core.telegram.org/bots/api#markdownv2-style
# - Use heredoc style to create the message and allow sending of newlines to survive the following pipeline:
#     bash | curl (GET, urlencode) | Telegram API
function get_msg_text {
	# Enable history, as it's not usually available from within bash scripts
	set -o history

	cat <<EOF
\`\`\`
# F\\-Droid command finished at:
# $(date)

# Command as entered:
\$ $(history | cut -c 8-)
\`\`\`
EOF
}

# Send a Telegram message via a bot
# #################################
function send_tg_alert {

	# Use heredoc style to create $MSG_TXT and allow sending of newlines to survive:
	# bash | curl (GET, urlencode) | Telegram API
	MSG_TXT=$(get_msg_text)

	echo "$MSG_TXT"

	# $TELEGRAM_CHATID and $TELEGRAM_BOTID should already exist in this container as environment variables,
	# having been passed in via the `docker run` command
	curl \
		--get \
		--data-urlencode "chat_id=${TELEGRAM_CHATID}" \
		--data-urlencode "parse_mode=MarkdownV2" \
		--data-urlencode "text=${MSG_TXT}" \
		https://api.telegram.org/bot${TELEGRAM_BOTID}/sendMessage
}

# Make functions available to the container and shell
# #################################
#
# If functions calls other functions, all functions in the chain need to be exported
export -f send_tg_alert
export -f get_msg_text


# Finish up...
# #################################
#
# Show some helpful reminders
cat << EOF

Example commands:

fdroid readmeta
fdroid rewritemeta com.example
fdroid checkupdates --allow-dirty com.example
fdroid lint com.example
fdroid build com.example


To send a Telegram message after the command has completed, append '; send_tg_alert', eg:

fdroid build com.example ; send_tg_alert

EOF


# Enter the directory which is most likely to be useful when the F-Droid commands are run
cd /build


# By default, the container would exit at the end of this ENTRYPOINT script --- start a shell instead.
/bin/bash "$@"

# Build the 'com.example.appname'
# then send a Telegram message
fdroid build com.example.appname ; send_tg_alert

# Build a package from source
fdroid build

# Read all the metadata files and exit
fdroid readmeta

# Rewrite all the metadata files
fdroid rewritemeta

# Warn about possible errors in the metadata
fdroid lint