Refactor entrypoint script for improved flexibility

Change the shebang to use env, add helper functions to handle environment variables, and dynamically append command arguments. This improves script flexibility and ensures critical variables are set or loaded from files.
This commit is contained in:
JRoot Junior 2024-10-21 02:01:29 +03:00
parent af7729be8d
commit 13e606c76b
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2 changed files with 94 additions and 68 deletions

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@ -1,5 +1,5 @@
ARG ALPINE_VERSION=latest
FROM alpine:${ALPINE_VERSION} as build
FROM alpine:${ALPINE_VERSION} AS build
ENV CXXFLAGS=""
WORKDIR /usr/src/telegram-bot-api

160
docker-entrypoint.sh Normal file → Executable file
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@ -1,87 +1,113 @@
#!/bin/sh
#!/usr/bin/env sh
set -e
USERNAME="telegram-bot-api"
GROUPNAME="telegram-bot-api"
COMMAND="telegram-bot-api"
# Appends an argument to the COMMAND variable.
append_args() {
COMMAND="$COMMAND $1"
}
# Sets $env_var from $file_env_var content or directly from $env_var.
# Usage: file_env <env_var> <file_env_var>
# - If both or neither variables are set, exits with an error.
# - If only $file_env_var is set, reads content from the file path and sets $env_var.
# - Exits with an error if the file does not exist.
file_env() {
local var_name="$1"
local file_var_name="$2"
env_var="$1"
file_env_var="$2"
env_value=$(printenv "$env_var") || env_value=""
file_path=$(printenv "$file_env_var") || file_path=""
var_value=$(printenv "$var_name") || var_value=""
file_path=$(printenv "$file_var_name") || file_path=""
if [ -z "$var_value" ] && [ -z "$file_path" ]; then
echo "error: expected $var_name or $file_var_name env vars to be set"
exit 1
elif [ -n "$var_value" ] && [ -n "$file_path" ]; then
echo "both and $var_name $file_var_name env vars are set, expected only one of them"
exit 1
else
if [ -n "$file_path" ] && [ "$file_path" != "" ]; then
if [ -f "$file_path" ]; then
file_content=$(cat "$file_path")
export "$var_name=$file_content"
else
echo "error: $var_name=$file_path: file '$file_path' does not exist"
if [ -z "$env_value" ] && [ -z "$file_path" ]; then
echo "error: expected $env_var or $file_env_var env vars to be set"
exit 1
fi
elif [ -n "$env_value" ] && [ -n "$file_path" ]; then
echo "both $env_var and $file_env_var env vars are set, expected only one of them"
exit 1
elif [ -n "$file_path" ]; then
if [ -f "$file_path" ]; then
export "$env_var=$(cat "$file_path")"
else
echo "error: $env_var=$file_path: file '$file_path' does not exist"
exit 1
fi
fi
}
# Checks if an environment variable is set.
# Usage: check_required_env <var_name>
# - Exits with an error if the variable is not set.
check_required_env() {
var_name="$1"
if [ -z "$(printenv "$var_name")" ]; then
echo "error: environment variable $var_name is required"
exit 1
fi
}
USERNAME=telegram-bot-api
GROUPNAME=telegram-bot-api
# Appends an argument to CUSTOM_ARGS based on the environment variable value.
# Usage: append_arg_from_env <var_name> <arg_name> <default_value>
# - If <var_name> is set, uses its value; otherwise, uses <default_value>.
# - Appends "<arg_name>=<value>" to CUSTOM_ARGS if a value is found.
append_arg_from_env() {
var_name="$1"
arg_name="$2"
default_value="$3"
env_value=$(printenv "$var_name") || env_value=""
chown ${USERNAME}:${GROUPNAME} "${TELEGRAM_WORK_DIR}"
[ -n "$env_value" ] || env_value="$default_value"
if [ -n "$env_value" ]; then
append_args "${arg_name}=$env_value"
fi
}
if [ -n "${1}" ]; then
exec "${*}"
fi
# Appends a flag to CUSTOM_ARGS if the environment variable is set (non-empty).
# Usage: append_flag_from_env <var_name> <flag_name>
# - If <var_name> is set, appends <flag_name> to CUSTOM_ARGS.
append_flag_from_env() {
var_name="$1"
flag_name="$2"
if [ -n "$(printenv "$var_name")" ]; then
append_args "$flag_name"
fi
}
check_required_env "TELEGRAM_WORK_DIR"
chown "${USERNAME}:${GROUPNAME}" "${TELEGRAM_WORK_DIR}"
# Telegram Bot API Server knows how to read the API ID and API Hash from a environment variable.
# Is not needed to pass it as arguments.
file_env "TELEGRAM_API_ID" "TELEGRAM_API_ID_FILE"
file_env "TELEGRAM_API_HASH" "TELEGRAM_API_HASH_FILE"
DEFAULT_ARGS="--dir=${TELEGRAM_WORK_DIR} --temp-dir=${TELEGRAM_TEMP_DIR} --username=${USERNAME} --groupname=${GROUPNAME}"
CUSTOM_ARGS=""
# Default arguments, passed from the Dockerfile.
# Potentially can be overwritten by environment variables, if needed, but is not recommended.
append_arg_from_env "TELEGRAM_WORK_DIR" "--dir"
check_required_env "TELEGRAM_TEMP_DIR"
append_arg_from_env "TELEGRAM_TEMP_DIR" "--temp-dir"
append_args "--username=${USERNAME}"
append_args "--groupname=${GROUPNAME}"
if [ -n "$TELEGRAM_LOG_FILE" ]; then
CUSTOM_ARGS=" --log=${TELEGRAM_LOG_FILE}"
fi
if [ -n "$TELEGRAM_STAT" ]; then
CUSTOM_ARGS="${CUSTOM_ARGS} --http-stat-port=8082"
fi
if [ -n "$TELEGRAM_FILTER" ]; then
CUSTOM_ARGS="${CUSTOM_ARGS} --filter=$TELEGRAM_FILTER"
fi
if [ -n "$TELEGRAM_MAX_WEBHOOK_CONNECTIONS" ]; then
CUSTOM_ARGS="${CUSTOM_ARGS} --max-webhook-connections=$TELEGRAM_MAX_WEBHOOK_CONNECTIONS"
fi
if [ -n "$TELEGRAM_VERBOSITY" ]; then
CUSTOM_ARGS="${CUSTOM_ARGS} --verbosity=$TELEGRAM_VERBOSITY"
fi
if [ -n "$TELEGRAM_MAX_CONNECTIONS" ]; then
CUSTOM_ARGS="${CUSTOM_ARGS} --max-connections=$TELEGRAM_MAX_CONNECTIONS"
fi
if [ -n "$TELEGRAM_PROXY" ]; then
CUSTOM_ARGS="${CUSTOM_ARGS} --proxy=$TELEGRAM_PROXY"
fi
if [ -n "$TELEGRAM_LOCAL" ]; then
CUSTOM_ARGS="${CUSTOM_ARGS} --local"
fi
if [ -n "$TELEGRAM_HTTP_IP_ADDRESS" ]; then
CUSTOM_ARGS="${CUSTOM_ARGS} --http-ip-address=$TELEGRAM_HTTP_IP_ADDRESS"
fi
check_required_env "TELEGRAM_API_ID"
check_required_env "TELEGRAM_API_HASH"
# Set http-port arg
if [ -n "$TELEGRAM_HTTP_PORT" ]; then
CUSTOM_ARGS="${CUSTOM_ARGS} --http-port=$TELEGRAM_HTTP_PORT"
else
CUSTOM_ARGS="${CUSTOM_ARGS} --http-port=8081"
fi
COMMAND="telegram-bot-api ${DEFAULT_ARGS}${CUSTOM_ARGS}"
# Environment variables that can be passed as arguments from environment by administrator.
append_arg_from_env "TELEGRAM_HTTP_PORT" "--http-port" "8081"
append_flag_from_env "TELEGRAM_LOCAL" "--local"
append_flag_from_env "TELEGRAM_STAT" "--http-stat-port=8082" # maybe change it to dynamic variable in the future
append_arg_from_env "TELEGRAM_LOG_FILE" "--log"
append_arg_from_env "TELEGRAM_FILTER" "--filter"
append_arg_from_env "TELEGRAM_MAX_WEBHOOK_CONNECTIONS" "--max-webhook-connections"
append_arg_from_env "TELEGRAM_VERBOSITY" "--verbosity"
append_arg_from_env "TELEGRAM_MAX_CONNECTIONS" "--max-connections"
append_arg_from_env "TELEGRAM_PROXY" "--proxy"
append_arg_from_env "TELEGRAM_HTTP_IP_ADDRESS" "--http-ip-address"
echo "$COMMAND"
# shellcheck disable=SC2086
exec $COMMAND