Prompt IP address selection during backend installation

References

Goals

1. Write a bash shell script to list all IP addresses into an array

2. Show the addresses as numeric options with a timed (eg. 10 seconds) prompt, see stackoverflow link above

3. Print the selected address, otherwise default to 127.0.0.1

YJ's Documentation

Aim

Shell Script

How does it work?

1. Store all IP addresses of the machine into an array.

2. For each IP address in the array, print out the IP address with its assigned number i.e. index.

3. Ask user to enter the number that corresponds to the desired IP address.
• If user entered a valid number from the list, set FRONTEND_IP to the selected IP address

• If user entered a number NOT from the list, set FRONTEND_IP to default 127.0.0.1

• If user does not enter within 10 seconds, set FRONTEND_IP to default 127.0.0.1

• If user enters without any input i.e. presses enter key without typing anything, set FRONTEND_IP to default 127.0.0.1

• If user's input is not a digit e.g. contains alphabets/special characters, set FRONTEND_IP to default 127.0.0.1

Codes

#!/bin/bash

# Store all IP addresses of the machine into an array
mapfile -t ipArray < <(ip a | awk '$1 == "inet" {gsub(/\/.*$/, "", $2); print $2}')

# List out the IP addresses stored in the array 
echo "List of IP addresses"
for key in "${!ipArray[@]}"
do
    echo "$key: ${ipArray[$key]}"
done

# Set FRONTEND_IP to default 127.0.0.1
FRONTEND_IP=127.0.0.1
# Ask user to enter the desired IP address
read -t 10 -p "Select the IP address that you wish to use e.g. 1: " option
# If user does not enter within 10 seconds, set FRONTEND_IP to default 127.0.0.1
if [[ $? -gt 128 ]] ; then
    echo -e "\nTimeout. Setting IP address to default 127.0.0.1..."
else
    # Check if input only contain numbers
    if ! [[ "$option" =~ [^[:digit:]]+ ]] ; then
        # If user enters without any input, set FRONTEND_IP to default 127.0.0.1
        if [[ $option = "" ]]; then 
                echo "No input entered. Setting IP address to default 127.0.0.1..."
        # If user entered a valid number from the list, set FRONTEND_IP to the selected IP address 
        elif [[ -v "ipArray[option]" ]] ; then
                echo "Valid number selected. Setting IP address to ${ipArray[option]}..."
                FRONTEND_IP=${ipArray[option]}
        # If user entered a number not from the list, it is an invalid number. Set FRONTEND_IP to default 127.0.0.1
        else
                echo "Invalid number selected. Setting IP address to default 127.0.0.1..."
        fi
    #If input does not contain only numbers, it is an invalid input. Set FRONTEND_IP to default 127.0.0.1
    else
        echo "Invalid input. Setting IP address to default 127.0.0.1..."
    fi
fi
# Print the selected IP address
echo "Selected IP address = $FRONTEND_IP"

References

Next Steps for Jym

1. Integrate into installcontainers.sh but installation becomes more complex

2. Use YJ's helper script to churn out a Caddy configuration to reverse proxy! Cleaner & flexible without the need to bring down the openedr-app container

Portable Bash Script can be a pain...

ip a not very portable

ifconfig | awk '$1 == "inet" {gsub(/\/.*$/, "", $2); print $2}'

macOS bash is v3 due to licensing constraint

Simplify Input Check

#!/bin/bash

# Store all IP addresses of the machine into an array
IPcmd="ifconfig"
if ! command -v ifconfig &> /dev/null
then
    # cases where ifconfig or net-tools is not installed or not there like macOS
    IPcmd="ip a"
fi

I=0
declare -a ipArray
ipArray=(`$IPcmd | awk '$1 == "inet" {gsub(/\/.*$/, "", $2); print $2}'`)

# List out the IP addresses stored in the array 
echo "List of IP addresses"
for key in "${!ipArray[@]}"
do
    echo "$key: ${ipArray[$key]}"
    I=$((I+1))
done

# Set FRONTEND_IP to default 127.0.0.1
FRONTEND_IP=127.0.0.1
# Ask user to enter the desired IP address
read -t 10 -p "Select the IP address that you wish to use e.g. 1: " option
# If user does not enter within 10 seconds, set FRONTEND_IP to default 127.0.0.1
if [[ $? -gt 128 ]] ; then
    echo -e "\nTimeout. Setting IP address to default 127.0.0.1..."
else
    # Check if input only contain numbers
    if [[ $option < $I ]] ; then
        # If user enters without any input, set FRONTEND_IP to default 127.0.0.1
        echo "Valid number selected. Setting IP address to ${ipArray[option]}..."
        FRONTEND_IP=${ipArray[option]}        
    else
        echo "Invalid input. Setting IP address to default 127.0.0.1..."
    fi
fi
# Print the selected IP address
echo "Selected IP address = $FRONTEND_IP"

my_function () {
  local func_result="some result"
  echo "$func_result"
}

func_result="$(my_function)"
echo $func_result

#!/bin/bash

# Set FRONTEND_IP to default 127.0.0.1
TIMEOUT=10
DEFAULT_ADDRESS=127.0.0.1

# Store all IP addresses of the machine into an array
IPcmd="ifconfig"
if ! command -v ifconfig &> /dev/null
then # cases where ifconfig or net-tools is not installed or not there like macOS
    IPcmd="ip a"
fi

I=0
declare -a ipArray
ipArray=(`$IPcmd | awk '$1 == "inet" {gsub(/\/.*$/, "", $2); print $2}'`)

# List out the IP addresses stored in the array 
echo "List of IP addresses"
for key in "${!ipArray[@]}"
do
    echo "$key: ${ipArray[$key]}"
    I=$((I+1))
done

prompt_address_selection() {
    # Ask user to enter the desired IP address
    return_value=$DEFAULT_ADDRESS
    read -t $TIMEOUT -p "$1" option
    # If user does not enter within 10 seconds, set FRONTEND_IP to default 127.0.0.1
    if [[ $? -gt 128 ]] ; then
        echo -e "\nTimeout. Setting IP address to default $DEFAULT_ADDRESS..."
    else
        # Check if input only contain numbers
        if [[ $option < $I ]] ; then
            # If user enters without any input, set FRONTEND_IP to default 127.0.0.1
            return_value=${ipArray[option]}        
        else
            echo "Invalid input. Setting IP address to default $DEFAULT_ADDRESS..."
        fi
    fi
}

# Prompt for selections
prompt_address_selection "Select FRONTEND address (set to $DEFAULT_ADDRESS after $TIMEOUT-sec timeout): "
FRONTEND_IP=$return_value
echo "Selected $FRONTEND_IP for FRONTEND web access."

prompt_address_selection "Select SFTP address (set to $DEFAULT_ADDRESS after $TIMEOUT-sec timeout): "
SFTP_IP=$return_value
echo "Selected $SFTP_IP for SFTP event-collection access."

1. fetching almost 300MB worth of image just to run a script to generate a .env file is stupid & slow

2. the more bash scripts, the more pain-points to ensure scripts run in multiple OS like macOS & linux variants