Recently I had to setup a deployment system from scratch. In the world of road side units and other DOT roadside devices firmware updates and patch deployments can be rough. Security is usually taken very seriously and getting access to the network segment for the devices you care for can be difficult to outright impossible.

To make matters more difficult for the maintainer many times there is no mass package deployment in place. Such was the case I ran into.

Disclaimer

I’m a strong proponent of testing before implementation. Therefore, I do not take any responsibility for your use of this information on your systems and the consequences that will ensue (good or bad). Remember the golden rules of IT:

1) Have a backup plan
2) Have a data backup

Follow these rules, and you will successfully recover most of the time.

Tools

This script specifically targets road side units however you can utilize these same principles for a variety of other projects.

1. Shell, as I work out of the terminal 98% of the time I use native commands in shell, preferably BASH when I can. This is not the best way (python would be better here actually).
2. Windows Subsystem Linux (you do not have to use this but I did and my scripts reflect this). I used Debian but there are other flavors that will work as well. Alpine, Busybox, etc will not be ideal choices for this exercise.
3. Install Python3
4. Install PSSH (uses python3), PSCP, etc
5. Install Curl, WGET, gzip

Picking up from Deployment Script I, this is where we get to use the cool PSSH, PSCP, and PNUKE tools.

PSSH

Let’s start with PSSH. With this you can connect to multiple devices via ssh at one time. Better than that you can use a key setup that will avoid having to type the password each time you run the command. The first step you will need for any of these tools is a simple text file filled with IP’s and the correct ssh port.

1.1.1.1:22
2.2.2.2:2222
3.3.3.3:22

You can name this file what you like but keep it short because we’ll use it later. Let’s define a function that will allow me to call a Rest API that will start a software function for connected vehicles.

startEtrans () {
if [[ $location -eq 1 ]]; then
ip_loc="/usr/local/bin/flagstaff_connects.txt"
elif [[ $location -eq 2 ]]; then
ip_loc="/usr/local/bin/rochester_connects.txt"
elif [[ $location -eq 3 ]]; then
ip_loc="/usr/local/bin/salem_connects.txt"
fi
echo "Start Etrans"
pssh -h $ip_loc -l root -i "-o StrictHostKeyChecking=no" "curl -s -o /dev/null -u 1Xmly02xivjsre:1Xmly02xivjsre http://localhost/apps/si?start=Start"
}

Let’s dissect this. First I start out with a series of “if” statements. If you remember part one we setup some case logic to determine what place we were working on. This simply checks the response of that function using numbers. Now, this is not the best way to do this. If the script gets really big figuring out what number goes where will get complicated. For small, quick, and dirty scripts this will work fine though.

At this point I set a variable for the text file filled with IP’s and ports that we set up earlier. Then the fun part. We call the pssh command. The “-h” switch takes the list of IP’s. Keep in mind this uses multi-threading so it is advised to keep the amount of IP’s limited. A specific number is not given in general likely as it depends on your network and computing equipment.

The next switch “-l” sets the user name. If you have keys for root already installed this is an easy way to keep things clean. it’s also the reason we are not use the “-A” switch. You need that switch if you’re running keyless and intend on putting in the password for the command.

The next part takes into account if the key has not been stored into your system before. If you don’t take this into account then the commands will fail.

Finally we run our command on multiple devices, at the same time. The neat thing is we can run chained commands or scripts. How to get the scripts on the device? Well, with PSCP of course.

PSCP

PSCP is known for being included with the Putty software. It is also included as part of the PSSH python package. This works in the same way as PSSH by allowing you to copy packages to multiple devices in much the same way. Let’s take a look at another function.

copySNMPScript() {
clear;
echo "########################################"
echo "Beginning SNMP Script Copy"
ip_loc="/usr/local/bin/rochester_connects.txt"
cd /mnt/c/Users/RMath/connects/snmp_scripts/;
echo "Copy over script"
pscp -A -h $ip_loc -l root -x "-o StrictHostKeyChecking=no" snmp_relaunch.sh /usr/bin/
echo "Fix Script Permissions and set in background"
pssh -A -h $ip_loc -l root -i -x "-o StrictHostKeyChecking=no" "cd /usr/bin/; chmod 755 snmp_relaunch.sh;"
echo "Reboot Device"
pssh -Av -h $ip_loc -p 1 -l root -x "-o StrictHostKeyChecking=no" "killall PT_Proxy"
echo "Tasks completed. Check for errors."
echo "########################################"
}

This function has a lot going on in it. We call PSSH and PSCP to copy over and fix permissions on the snmp script. Specifically though we’ll focus on PSCP. This time since we don’t have a key on the device we have to tell PSCP that it must ask us for the password. For each command we run with a “-A” switch we will be forced to input the password. The rest of it we just ran through. At the end of the day it basically works like SCP, just on a larger scale.

PNUKE

The final command we will run is PNUKE. This is useful for killing services. Not much is said about this command online but I found it works a lot like the “kill -9 <pid>” command. Below is another function with an example of PNUKE usage. Basically it searches the services for the item you’re looking for and applies a “kill -9” command.

connectEtrans() {
clear;
echo "########################################"
echo "Beginning Connect:ITS Etrans Upgrade Deployment Process"
if [[ $location -eq 1 ]]; then
ip_loc="/usr/local/bin/flagstaff_connects.txt"
elif [[ $location -eq 2 ]]; then
ip_loc="/usr/local/bin/rochester_connects.txt"
elif [[ $location -eq 3 ]]; then
ip_loc="/usr/local/bin/salem_connects.txt"
fi
cd /mnt/c/Users/RMath/OneDrive\ /Etrans/$version;
echo "Copy over Etrans"
pscp -h $ip_loc -l root -x "-o StrictHostKeyChecking=no" kapschrcu-connectits-$version.gz /tmp/
echo "Unzip"
pssh -h $ip_loc -l root -i -x "-o StrictHostKeyChecking=no" "sed -i 's/1/0/g' /etc/apt/apt.conf.d/20auto-upgrades;cat /etc/apt/apt.conf.d/20auto-upgrades;"
pssh -h $ip_loc -l root -i -x "-o StrictHostKeyChecking=no" "gunzip /tmp/etrans-connectits-$version.gz"
echo "Kill etrans process"
pnuke -h $ip_loc -l root -x "-o StrictHostKeyChecking=no" "etransrsu"
echo "Install new etrans"
pssh -h $ip_loc -l root -i -x "-o StrictHostKeyChecking=no" "rm -rf /opt/etrans/etransrsu; mv /tmp/etrans-connectits-$version /opt/etrans/etransrsu; chmod 755 /opt/etrans/etransrsu;"
echo "Clean up"
pssh -h $ip_loc -l root -i -x "-o StrictHostKeyChecking=no" "rm -rf /tmp/*"
echo "Restart Etrans"
pssh -h $ip_loc -l root -i "-o StrictHostKeyChecking=no" "curl -s -o /dev/null -u 1Xmly02xivjsre:1Xmly02xivjsre http://localhost/apps/si?start=Start"
echo "Tasks completed. Check for errors."
echo "########################################"
}

That’s it for our walk through on setting up a deployment script. Using PSSH and PSCP you can make a rudimentary deployment service for immature environments that don’t support agents or places you cannot place keys (embedded systems, really poorly run IT environments with broken deployment systems requiring manual installs, or small business applications). This is better built directly in python but for a quick and dirty setup it’s hard to beat a Windows Subsystem Linux setup, OneDrive, and a nice deployment bash script.

Recently I had to setup a deployment system from scratch. In the world of road side units and other DOT roadside devices firmware updates and patch deployments can be rough. Security is usually taken very seriously and getting access to the network segment for the devices you care for can be difficult to outright impossible.

To make matters more difficult for the maintainer many times there is no mass package deployment in place. Such was the case I ran into.

Disclaimer

I’m a strong proponent of testing before implementation. Therefore, I do not take any responsibility for your use of this information on your systems and the consequences that will ensue (good or bad). Remember the golden rules of IT:

1) Have a backup plan
2) Have a data backup

Follow these rules, and you will successfully recover most of the time.

Tools

This script specifically targets road side units however you can utilize these same principles for a variety of other projects.

1. Shell, as I work out of the terminal 98% of the time I use native commands in shell, preferably BASH when I can. This is not the best way (python would be better here actually).
2. Windows Subsystem Linux (you do not have to use this but I did and my scripts reflect this). I used Debian but there are other flavors that will work as well. Alpine, Busybox, etc will not be ideal choices for this exercise.
3. Install Python3
4. Install PSSH (uses python3), PSCP, etc
5. Install Curl, WGET, gzip

Beginning the Script

I always start my scripts with variables

#!/bin/bash
#########################################
# Script Name: Deployment System
# Date:        1/3/2021
# Author:      Robert Mathis
#########################################

#########################################
# Variables
#########################################

version='1.2.3'
container_image='https://microsoft_one_drive&download=1'
answer=1;

If you’ve not worked with scripting before, don’t fear, variables are fun! You can stick useful bits into them, often things that repeat throughout your script that would be a pain to change by hand. Of course there are other uses for variables but for now just think of them as boxes or containers.

Case Logic

Next we go right for the jugular with some basic questions. To do this we’re going to create some functions.

#########################################
# Functions
#########################################

locationsetup() {
while true; do
clear
echo "Upgrade System for Somewhere"
echo "This upgrade provided by Something"
echo "########################################"
echo ""
echo "Location Selection"
echo "########################################"
echo "1 Flagstaff"
echo "2 Rochester"
echo "3 Salem"
echo "########################################"
read -p "Where are we upgrading? Enter a number: " location
echo ""
  read -r -p "Is location $location correct?? [y/n]" answer
  case "$answer" in
        [Yy][Ee][Ss]|[Yy]) # Yes or Y (case-insensitive).
        return 0
        ;;
      *) # Anything else (including a blank) is invalid.
        ;;
  esac
done
}

deploymentsetup() {
while true; do
clear
echo ""
echo "Deployment Type"
echo "########################################"
echo "1 Connect:ITS Something"
if [[ $location -eq 2 ]];
then
echo "2 CVCP Something"
echo "3 VCCU Something"
fi
echo "########################################"
read -p "Enter the number of the deployment you would like to complete: " deployType
echo ""
  read -r -p "Is deployment type $deployType correct? [y/n]" answer
  case "$answer" in
        [Yy][Ee][Ss]|[Yy]) # Yes or Y (case-insensitive).
        return 0
        ;;
      *) # Anything else (including a blank) is invalid.
        ;;
  esac
done
}

The first thing you might notice is that we start with a function. Something like this:

function () {}

We can put arguments in the function if we want but what we’re after is some simple answers to some questions. The idea being to automate this process as much as possible.

We use a “while” loop to kick off both of our functions. The while loop has one purpose. It’s to ensure that if an answer is not typed in correctly the user of the script can retype their new answer in before proceeding. To make the while loop work we set a variable at the beginning called “answer”. If “yes” is not specified a 1 is returned. The loop will start over again until a 0 is returned which would be a successful function exit.

One thing to remember is that when checking against integers as opposed to strings (numbers verses words) double brackets need to be used for if statements. Also the “-eq” operator as opposed to the “==” operator needs to be used. The rest is fairly self explanatory and fairly reusable. To call the function simply invoke it like so:

#########################################
#Execution
#########################################

locationsetup; deploymentsetup;

Because we did not have arguments for the function there is no need for anything further. But if we did have arguments they would look like the following:

snmp_array_walker() {
  arr=("$@");
  for x in "${arr[@]}";
    do
       echo "Working on OID $x";
       snmpget -v 2c -c public $ip $x;
       echo " ";
       sleep 1;
    done;
}

In this script the function is expecting an array to be passed to it. In the world of shell you pass the argument in the following way:

snmp_array_walker "${array1[@]}"

You may not realize this but many times in Alpine or older Debian (9 and prior) versions calling something like the following:

service mysql status

Is the equivalent to calling a function with an argument. In fact if you were to go about it this way it would look far more familiar perhaps:

/etc/init.d/mysql status

In this case we’ve simply passed one of the function arguments to the service.

Going back to the earlier example with the function and the array. What happened here was we called the function and then passed one of the arrays to it. The argument is placed beside the function. There can be as many arguments as needed. In this case this is a special way to pass an array to the function. Basically I’ve requested the array1 variable and have called every item of the array to be passed to the function.

Stay tuned for part two when we actually get to walk through some other useful functions and if statements.

Recently I ran into a stone-cold problem. I had to get an advanced version of SNMPv3 with upgraded SHA and AES working on some units in the field. Well, it turns out that as of today’s writing, the default SNMP package for Debian Stretch (9) and Buster (10) is 5.7 which doesn’t have the upgraded SNMP. But they do have a package for 5.8 that is being tested and is also in the unstable channel. Bad news is it won’t build due to some missing Debian tools. The good news is I have a lot of time with Gentoo, and this isn’t my first compiling rodeo. So between the work already done to show which packages I need for my dependencies, I just needed to put the correct commands to work. The problem was, I didn’t know what commands I would need.

So after a long and drawn-out fight with multiple false starts, including an overlooked but important option for AES-256 enablement in the configure file, I have gotten the process down for this package, and I’d like to share some Debian and Docker friendly ways to jump on this. I’ll even give you a way to make this portable for offline systems. The amount of commands will look daunting perhaps and dense, but it’s not that bad really. Mostly a lot of words, but you like reading right? I’m joking. Just don’t get daunted by it.

Disclaimer

I’m a strong proponent of testing before implementing. Therefore, I do not take any responsibility for your use of this script on your systems and the consequences that will ensue (good or bad). Please do not just run this on a Gentoo system without first backing up your files. Remember the golden rules of IT:

1) Have a backup plan
2) Have a data backup

Follow these rules, and you will successfully recover most of the time.

Tools Needed

1. An operating system. I will ultimately test this on a physical box, but to start with I work in Windows so I can take advantage of some of the other tools listed below.
2. WinSCP (If you’re using Windows, and for this, it’s almost, almost worth using Windows just to use this awesome, free tool)
3. Putty, or if you’re on Linux, SSH
4. Docker for Desktop (Windows if you want to follow along, but you can do this using Docker installed on Linux). Keep in mind you’ll need a login to download Docker for Desktop. It’s worth it for the personal free repository alone. If you do have to or want to install it ensure you have Hyper-V turned on in advance. It will save you some time and grief as it will require a reboot if it’s not already on. Read this post by Microsoft to get yours set up.
5. Internet connection with both systems on the same network if you’re testing. Otherwise, you’ll just need the internet for the online portion.
6. My two posts on offline packages. This will give you an idea for capturing the dependency packages you’ll need. Updating Debian Offline 1 of 2. Updating Debian Offline 2 of 2.

Docker Container Code for Inside the Container

#!/bin/bash

##Make it easy to read
apt-get update;

apt-get install -y build-essential fakeroot devscripts checkinstall;

echo "deb-src http://httpredir.debian.org/debian unstable main" >> /etc/apt/sources.list;

apt-get update;

cd /;

mkdir -p src/debian;

cd /src/debian;

apt-get source net-snmp; 

apt-get install -y libwrap0-dev libssl-dev perl libperl-dev autoconf automake debianutils bash findutils procps pkg-config libbsd-dev default-libmysqlclient-dev libpci-dev; 

cd /src/debian/net-snmp-5.8+dfsg;

mkdir build;

##Include either option 1 or option 2 in script

#Option 1 Configure to ouput the compiled sources to the build folder I point it to.
./configure --prefix=/src/debian/net-snmp-5.8+dfsg/build/ --with-transports="DTLSUDP" --with-security-modules="tsm" --enable-blumenthal-aes --with-default-snmp-version="3" --with-sys-contact="@@no.where" --with-sys-location="Unknown" --with-logfile="/var/log/snmpd.log" --with-persistent-directory="/var/net-snmp" && make && checkinstall

#Option 2 Configure no ouput and accept the defaults This one is what
#you want. It will out put a .deb file for you in the same directory.

./configure --with-transports="DTLSUDP" --with-security-modules="tsm" --enable-blumenthal-aes --with-default-snmp-version="3" --with-sys-contact="@@no.where" --with-sys-location="Unknown" --with-logfile="/var/log/snmpd.log" --with-persistent-directory="/var/net-snmp" && make && checkinstall

Container Code as a One-Liner with Direction to Build Folder

apt-get update;apt-get install -y build-essential fakeroot devscripts checkinstall;echo "deb-src http://httpredir.debian.org/debian unstable main" >> /etc/apt/sources.list;apt-get update;cd /;mkdir -p src/debian;cd /src/debian;apt-get source net-snmp; apt-get install -y libwrap0-dev libssl-dev perl libperl-dev autoconf automake debianutils bash findutils procps pkg-config libbsd-dev default-libmysqlclient-dev libpci-dev; cd /src/debian/net-snmp-5.8+dfsg;mkdir build;./configure --prefix=/src/debian/net-snmp-5.8+dfsg/build/ --with-transports="DTLSUDP" --with-security-modules="tsm" --enable-blumenthal-aes --with-default-snmp-version="3" --with-sys-contact="@@no.where" --with-sys-location="Unknown" --with-logfile="/var/log/snmpd.log" --with-persistent-directory="/var/net-snmp" && make && checkinstall

Docker Code

##Well this is crappy. Why do I call with it an interactive switch?
##Why do I restart that container? Did I exit?
##Why am I copying things and then getting back in the container?

docker run -it --network bridge -h deb --name deb debian:stretch /bin/bash;docker start deb;docker cp .\depends\ deb:/tmp;docker exec -it deb /bin/bash


#If you are in the /src/debian/net-snmp_5.8+dfsg/ folder
#./configure --with-default-snmp-version="3" --with-sys-contact="@@no.where" --with-sys-location="Unknown" --with-logfile="/var/log/snmpd.log" --with-persistent-directory="/var/net-snmp" && make && checkinstall

##checkinstall depends for copy and paste
libwrap0-dev,libssl-dev,perl,libperl-dev,autoconf,automake,debianutils,bash,findutils,procps,pkg-config,libbsd-dev,default-libmysqlclient-dev,libpci-dev

The Breakdown

To kick this off, you have one of two ways of going about this. I’m going to keep this on the Debian side of things and call in their test package, but I actually ended up going to source directly and building from there. In that case, you still want to install all of the recommended installs like build-essential, fakeroot, devscripts, and checkinstall. Then you can just run the configuration that I have in the source folder.

But if you want to just work through the Debian commands, which admittedly is a little easier, that is what the script above will do.

You will need to get the dependencies for this package. I have them listed out here:

automake_1%3A1.15-6_all.deb
autotools-dev_20161112.1_all.deb
bzip2_1.0.6-8.1_amd64.deb
default-libmysqlclient-dev_1.0.2_amd64.deb
libbsd-dev_0.8.3-1_amd64.deb
libbsd0_0.8.3-1_amd64.deb
libc-dev-bin_2.24-11+deb9u4_amd64.deb
libc6-dev_2.24-11+deb9u4_amd64.deb
libc6_2.24-11+deb9u4_amd64.deb
libdpkg-perl_1.18.25_all.deb
libffi6_3.2.1-6_amd64.deb
libfile-fcntllock-perl_0.22-3+b2_amd64.deb
libgdbm3_1.8.3-14_amd64.deb
libglib2.0-0_2.50.3-2+deb9u2_amd64.deb
libglib2.0-bin_2.50.3-2+deb9u2_amd64.deb
libglib2.0-data_2.50.3-2+deb9u2_all.deb
libgpm2_1.20.4-6.2+b1_amd64.deb
libicu57_57.1-6+deb9u3_amd64.deb
liblocale-gettext-perl_1.07-3+b1_amd64.deb
libmariadbclient-dev-compat_10.1.44-0+deb9u1_amd64.deb
libmariadbclient-dev_10.1.44-0+deb9u1_amd64.deb
libmariadbclient18_10.1.44-0+deb9u1_amd64.deb
libncurses5_6.0+20161126-1+deb9u2_amd64.deb
libpci-dev_1%3A3.5.2-1_amd64.deb
libpci3_1%3A3.5.2-1_amd64.deb
libperl-dev_5.24.1-3+deb9u6_amd64.deb
libperl5.24_5.24.1-3+deb9u6_amd64.deb
libprocps6_2%3A3.3.12-3+deb9u1_amd64.deb
libsigsegv2_2.10-5_amd64.deb
libssl-dev_1.1.0l-1~deb9u1_amd64.deb
libssl-doc_1.1.0l-1~deb9u1_all.deb
libssl1.1_1.1.0l-1~deb9u1_amd64.deb
libudev-dev_232-25+deb9u12_amd64.deb
libudev1_232-25+deb9u12_amd64.deb
libwrap0-dev_7.6.q-26_amd64.deb
libwrap0_7.6.q-26_amd64.deb
libxml2_2.9.4+dfsg1-2.2+deb9u2_amd64.deb
linux-libc-dev_4.9.210-1_amd64.deb
m4_1.4.18-1_amd64.deb
manpages-dev_4.10-2_all.deb
manpages_4.10-2_all.deb
mysql-common_5.8+1.0.2_all.deb
net-snmp_5.8_amd64.deb
netbase_5.4_all.deb
perl-base_5.24.1-3+deb9u6_amd64.deb
perl-modules-5.24_5.24.1-3+deb9u6_all.deb
perl_5.24.1-3+deb9u6_amd64.deb
pkg-config_0.29-4+b1_amd64.deb
procps_2%3A3.3.12-3+deb9u1_amd64.deb
psmisc_22.21-2.1+b2_amd64.deb
rename_0.20-4_all.deb
sgml-base_1.29_all.deb
shared-mime-info_1.8-1+deb9u1_amd64.deb
tcpd_7.6.q-26_amd64.deb
udev_232-25+deb9u12_amd64.deb
xdg-user-dirs_0.15-2+b1_amd64.deb
xml-core_0.17_all.deb
autoconf_2.69-10_all.deb
xz-utils_5.2.2-1.2+b1_amd64.deb
zlib1g-dev_1%3A1.2.8.dfsg-5_amd64.deb

To obtain them from where they downloaded you can read from this post. Pay attention to the “lists” acquisition and acquiring the packages from a cleaned archives folder. Now the bad news. Unfortunately, if you’re using the docker container option, you need to be aware of something very important. The archives clean up as soon as the install of a package starts. You need to circumvent this by having a second terminal open and copying the packages upon download to somewhere like the /tmp/ folder (which I would have cleaned first). Then you can retrieve them like so:

docker cp deb:/tmp/ .

What I did here was copy the files in the /tmp/ directory to the local folder (.) where I’m at. I’m assuming the container’s name is “deb” although yours might be named differently.

The biggest thing to remember is that this will be installed favoring the following command over the apt-get command I used in the post I referred to earlier.

apt-get update --no-download; dpkg -i *.deb;

The AES-256 Net-SNMP 5.8 Struggle Bus

So perhaps you want to know a little more about some of the switches in that configure call. Three of them were required, from my experience anyway, to get things to install without having to answer questions. But the real money is these flags:

–with-transports=”DTLSUDP”
–with-security-modules=”tsm”
–enable-blumenthal-aes

If you don’t have those three flags set, you can forget about AES-256, and that, my friends, makes the whole exercise pointless, right? Incidentally, this is why it’s important to have OpenSSL installed as this is where it will be pulling the crypto-library.

Checkinstall? What’s that do?

##checkinstall dependencies for copy in
libwrap0-dev,libssl-dev,perl,libperl-dev,autoconf,automake,debianutils,bash,findutils,procps,pkg-config,libbsd-dev,default-libmysqlclient-dev,libpci-dev

As I was fighting my way through trying to actually make a .deb package, I found an easy way. A dead-easy way. The checkinstall package will make the .deb file for you and even install it. It makes sure that anything that gets installed in the package can be removed using the standard package tools included with Debian.

How do I get this all installed?

####To install the full monty:

#Copy the full depends folder to your target computer
#Inside of the depends folder go ahead and put the newly built snmp pkg
#I'd rename the deb file for easier reference
#inside of the depends folder run "dpkg -i *.deb"

What if I want to uninstall it?

/src/debian/net-snmp-5.8+dfsg/net-snmp_5.8+dfsg-1_amd64.deb

 You can remove it from your system anytime using:

      dpkg -r net-snmp

This prints out on the screen. I will give you the uninstall script as well.

Package Builder:

pkg installer notes:

#You might need to install xz-utils package if on container debian:stretch

#You can find out if you have xz-utils installed by running:
apt-cache pkgnames | grep -w ^xz

#create pkg zip xz, note the output deb file I already renamed
tar -cJvf net-snmp_5.8.tar.xz net-snmp_5.8;rm -rf net-snmp_5.8;

#unpackage and install (scripts perform cleanup)
#Does not take into account paths, assumes local directory execution
tar -xJvf net-snmp_5.8.tar.xz;cd net-snmp_5.8;chmod a+x snmp_*;./snmp_install

Install Script

#!/bin/bash

##Assumes root is running
##We know we are now in /root/mhcorbin/cam1/

## Variable to path
exists=/root/.snmp
flderpth=/root/mhcorbin/cam1/net-snmp_5.8
tarcleaner=/root/mhcorbin/cam1/net-snmp_5.8.tar.xz
pkgcheck=$(apt-cache pkgnames | grep -w ^snmp)

## Fix where am I running issue
cd $flderpth;
## Fix apt update lists so pkgs install properly
rm -rf /var/lib/apt/lists/*;
sleep 5;
cp -RTv $flderpth/lists /var/lib/apt/lists;
apt-get update --no-download;
#  Allow time for dpkg lock to release before deleting lock file
sleep 10;

#  Clear DPKG lock to resolve lock error
rm /var/lib/dpkg/lock;

##Determine if a prior SNMP package is installed and if so remove it
if [ -z "$pgkcheck"  ];then
	apt-get -y -f --purge remove snmp;
fi

##Determine what kind of install to perform
if [ -d $exists ]; then
##Install only
	dpkg -i $flderpth/*.deb;
	rm -rf $flderpth/mibs $flderpth/*.deb $flderpth/lists $flderpth/snmp_install
	echo "install only";
else
##Fix Missing Mibs with RSU-MIB included
	dpkg -i $flderpth/*.deb;
	echo "mibs and install";
	mkdir -p /root/.snmp/mibs;
	cp -RTv $flderpth/mibs /root/.snmp/mibs;
	sleep 5;
	rm -rf $flderpth/mibs $flderpth/*.deb $flderpth/lists $flderpth/snmp_install
fi

if [ -f $tarcleaner ]; then
	rm -rf $tarcleaner;
fi

Uninstall Script

#!/bin/bash

dpkg -r net-snmp libwrap0-dev libssl-dev libperl-dev autoconf automake pkg-config libbsd-dev default-libmysqlclient-dev libpci-dev

Conclusion

This was quite a slog, but if you’re still with me, hopefully this has given you an idea of how to put this together. As always, I’m open to comments and alternative ideas. Thanks for reading!

This post is about something I tried when I was working on an offline Debian upgrade project. While it didn’t ultimately provide the solution to that project, it did open up a wonderful possibility. To kick this post off, we must have a talk about dependencies, and since that can become mind numbing quickly, I’m only going to gloss over that topic. We’ll talk about what this script does, how to use it, and then turn you loose.

Dependencies _> The Underworld

Dependencies are what the majority of packages or projects rely on to work. Think of it like a base foundation that many people contribute to. This is usually in the form of “lib” or library packages. Other developers will use this pre-written code in their projects, and that’s the end of it right? Not really. Actually, a single project can use dozens to hundreds of dependencies all stacked upon one another like a pyramid of code. This can quickly become a large security issue as the more a system has installed the more dependencies it relies upon. It is at that point that the system’s security becomes more and more dependent (no pun intended) upon every dependency. In other words, the weakest link in any program is the amount of dependencies it uses as much as a chain is only as strong as its weakest link. 

So there’s some of the ugly; let’s talk about the bad for a second. Let’s say you’ve gotten entangled in a project that needs some offline packages installed. Where do you start?

The Journey

For me I started at the online Debian package repository. I needed to download Java for another project. Needless to say you quickly find that you need at least four packages right off the bat.

openjdk-8-jre.deb openjdk-8-jre-headless.deb openjdk-8-jdk-headless.deb openjdk-8-jdk.deb

Yikes! Each package has even more dependencies. And those have even more dependencies. Wouldn’t it be nice if you could just get all the packages and the dependencies without the downloads?

The Solution

I was getting desperate for a solution. Downloading package after package after package is the worst. I have a life and better things to do. Enter salvation in the form of ingenius scripting from OSTechNix. Simply make a folder of the package you wish to download and get cracking.

Here’s the code again below for reference. We’ll step through it.

#!/bin/bash

read -p "What pkg are you building?: " pkg

##Code attribution for the code below
##https://www.ostechnix.com/download-packages-dependencies-locally-ubuntu/

for i in $(apt-cache depends $pkg | grep -E 'Depends|Recommends|Suggests' | cut -d ':' -f 2,3 | sed -e s/'<'/''/ -e s/'>'/''/); do sudo apt-get download $i 2>>errors.txt; done

The Code

I’m going to assume you have made your directory and you are ready to proceed to the next step. If you want you can copy the script above and put it in your /usr/local/bin which will make your script available in your system paths. Make sure it’s executable. I usually run my scripts as root on test systems, so for your system you may wish to use “sudo” in front of whatever you named this script.

read -p "What pkg are you building?: " pkg

This is the first line I added, and it offers some bonuses. You can put as many different packages as you want, spaced out of course. It’s a simple input line for bash with the variable at the end. As you can see, we use that later.

for i in $(apt-cache depends $pkg | grep -E 'Depends|Recommends|Suggests' | cut -d ':' -f 2,3 | sed -e s/'<'/''/ -e s/'>'/''/) 
     do 
        sudo apt-get download $i 2>>errors.txt
     done

I’m going to skip over the code attribution because I think that’s rather self-documenting. The rest of this code starts with a standard for loop. What follows next is a calling of the apt-cache command and the depends command for the package ($pkg, told you we’d use it later) you want to download. Then we pipe to grep, doing a little cutting, run sed (which does some awesome clean up), and then we finally get to downloading the packages.

Wrapping it up

Before you start running this script, make sure you’re in the actual folder you created. Otherwise you could end up with a lot of deb packages everywhere. Not to worry if you did though. Here’s some shortcode to get things cleaned up. We’ll assume you’re in the /tmp/ folder, and you ran, for example, the java packages I listed out earlier. What a mess!

cd /tmp/
##gotta get in the tmp directory first right?
##remember the java folder (package folder) I made?
mv *.deb /tmp/java

And boom. You’re all good. Hope it helps.

If you’ve been following along, you’ve gotten all of your offline files ready for deployment. If you missed that section you can go there now. In the sections below, we’ll discuss: the offline deployment, suggestions for running your offline deployment, and finally some fascinating ideas and projects I tried which have interesting potential but, unfortunately, did not work for me in this instance.

Disclaimer

This guide strictly deals with upgrading your system. It will not cover dist-upgrade although that is certainly something you can try and test. This information is provided as-is and, therefore, I take no responsibility for incidents with your equipment. I am a huge proponent of testing. Please ensure you know what you are doing before you attempt this.

Tools you need

1. WinSCP (If you’re using Windows and, for this, it’s almost, almost worth using Windows just to use this awesome, free tool)
2. Two systems. One should be online and the other is, of course, the offline one. They both should be very close build-wise. NOTE: If you want to test this out, I recommend changing the /etc/resolv.conf file on one of the systems. Comment: Remove everything in there and save it. This ensures apt will break without using the correct options and your test is as clean as it’s going to get without introducing USB flash drives.
3. Putty, or if you’re on Linux, SSH
4. Internet connection with both systems on the same network if you’re testing. Otherwise, you’ll just need internet for the online portion.

Copying over the Needed Files to the Offline System

Are you ready to get this done?

We’ll use WinSCP and transfer our files over to the “offline” system in its /tmp/ folder assuming it’s on your network and the only edits you made were to the /etc/resolv.conf file for testing. Otherwise, if you cannot reach your offline system with a network connection, you’ll have to use a flash drive. Mounting a flash drive is out of scope for this post, but the rest of the commands are relevant to your endeavor.

Assuming you’ve connected to your remote system with WinSCP, it’s time to copy some files over. This is where WinSCP shines because it saves so much time. We’re going to specifically copy over the:

1. Archives folder
2. Lists folder
3. Any additional packages (if its a .deb just put it in the archives folder once you’ve noted the full package name including its .deb extension) or scripts you may need.

We’re going to place these folders/files into the /tmp/ directory. Once everything is in the directory, assuming you kept the file names, we can get the actual update process started.

Spark Note From the Forge

Be a boss. Tar your files or zip them to make the transfer faster. Why? Because an archive, tar, or zip presents as a single file. The network won’t speed up and slow down as it finishes a file and starts a new one. Instead, as an archive or zip shows up as a single file the network keeps the pedal to the floor the entire way through. Want more mileage? Go full bore and use “xz” compression.

Moving files to the correct directories and cleanup

I kept the file names the same, so starting the in the /tmp/ directory I will run the following:

## Time to make the money. Clean out the archives section first. Make room on the tiny system.
## Move in the new archives and lists and clean up.
cd /tmp/;
apt-get clean;
mv archives/* /var/cache/apt/archives;
rm -rf archives;
rm -rf /var/lib/apt/lists/*;
mv lists/* /var/lib/apt/lists/;
rm -rf lists;

Can this be written more elegantly? Yes. But my intent is to fully show what I’m doing. Do I need semicolons at the end of these? No, but I tend to like to chain my commands together for situations where I can only paste one line into the terminal as it doesn’t make sense to write a script if I’m going to be on and off the system quickly. Believe me, I have found in the world of embedded systems that that happens. Like with Road Side Units (RSU) where you may be doing the same thing with very little variation dozens of times. You may love vi (one of the oldest unix/linux text editors), but me, not so much.

If everything has completed properly then we start pulling the triggers on things.

Running the Offline Update and Upgrades – Finally!

sed -i 's/jessie/stretch/g' /etc/apt/sources.list;
apt-get update --no-download;
apt-get upgrade -yf --no-download --ignore-missing;

For the upgrade, you can try this instead to keep the default options, but I have not had much success with it:

DEBIAN_FRONTEND=noninteractive apt-get upgrade -yf --no-download --ignore-missing -o "Dpkg::Options::=--force-confdef" -o "Dpkg::Options::=--force-confold";

So what does all of this do? If you remember from the previous blog, the sed command changed over “jessie” to “stretch” in one line. You can change the words to be what you need. For instance, you could make it look like this:

sed -i 's/stretch/buster/g' /etc/apt/sources.list;

But for this case, whatever you used on the online system must be used for the offline system. Is it really necessary? For documentation purposes at a minimum, yes. It’s a cheap, short, lazy way to let folks know what the offline system has. Don’t be that guy that leaves other folks wondering.

The next line simply updates the package lists in the system. This is important as we want the package database to be updated with the latest packages for our distributions archives we just moved from /tmp/ to the archives folder.

Once we get to the upgrade line, you’re in the home stretch. The system should be able to begin checking the archive folder for the necessary packages and will begin the upgrade process. I found there was no automation on my side as sometimes I needed glibc to be upgraded, for instance, which brought up a blue screen (updating grub will also bring up a blue screen requesting input). With that in mind, I’d plan to stick around and see things through.

But wait! What about my other offline packages that are not part of the main repository? Like that influxdb package, you pulled down. What happens there? Does apt-get upgrade or apt-get install work for that?

Not in my experience. What I did was throw those packages in the archives folder and then used dpkg to install it like so:

pushd /var/cache/apt/archives;dpkg -i influxdb_1.7.9-1_amd64.deb;popd

This is, again, not the slickest way you can write this, but, hopefully, it gives you an idea for a one-liner install.

Things I Tried that Failed

My main, initial challenge was that I had no internet on the remote boxes I needed to reach. I had a vpn connection and ssh. So naturally I tried to do a reverse ssh proxy which failed for me. I tried using port forwarding with ssh as well, and again, it didn’t come through. Trying to provide internet to a remote box over vpn was making me bang my head!

Time for plan b, and that turned out to be a project called sshuttle. It’s a neat project written in python that performs as a sublevel vpn, dns tunnel and more. It didn’t work out for me, but it might work out for you. Here’s what the project creator had to say on their github:

“Transparent proxy server that works as a poor man’s VPN. Forwards over ssh. Doesn’t require admin. Works with Linux and MacOS. Supports DNS tunneling.”

https://github.com/sshuttle/sshuttle

Spark Note From the Forge

What a bummer! I couldn’t get this python project installed right away. I’m so accustomed to working with linux scripts that it didn’t cross my mind that you might need to run a python project with a python installer! This project does need a separate project called “setuptools“.

Inside of that project, you will need to run an initial setup script as well. Another “gotchya” is you will need to match the version of setuptools that the creator of sshuttle is using, but here is a link you can use to get an idea and get started (https://pypi.org/project/setuptools/).

Well how do I install this project offline then? You will need to get all the project files, and then do what you’ve done with the archive files and copy them to /tmp/. Change directory into that file. From there, you can run the following code to install it on the user account you are logged into the remote system with:

python install setup.py –user

Well, so much for sshuttle then. I also gave a project called apt-offline a try. This was promising, but in the end, it also didn’t fulfill my needs. It did, however, set me down the path to understanding the Debian system better. While this project simplifies things for the average user, it still didn’t do everything I wanted. You can check out that project here if you want to give it a try: (https://github.com/rickysarraf/apt-offline).

That wraps it up for this post. Hopefully, you found the droids you were looking for and this has been useful.

As part of an R&D project, I had to find a way to update a few old systems we have in the field that have been completely locked down (i.e. you can use a VPN to visit but that’s it). There is no DNS and no other external internet connection. To add to the challenge, I needed to work with a system that has 3.4GB of storage with 2.5GB of it used, and I needed to update Java and install some other test .deb files. In this series, I’ll tell you what I did to make it work, what I tried that didn’t work, and how you can be your own offline master.

Disclaimer

This guide strictly deals with upgrading your system. It will not cover dist-upgrade although that is certainly something you can try and test. This information is provided as-is, and, therefore, I take no responsibility for incidents with your equipment. I am a huge proponent of testing. Please ensure you know what you are doing before you attempt this.

Tools you need

1. WinSCP (If you’re using Windows and, for this, it’s almost, almost worth using Windows just to use this awesome, free tool)
2. Two systems. One should be online and the other is, of course, the offline one. They both should be very close build-wise. NOTE: If you want to test this out, I recommend changing the /etc/resolv.conf file on one of the systems. Comment out everything in there and save it. This ensures apt will break without using the correct options and your test is as clean as it’s going to get without removing an ethernet cable and introducing USB flash drives.
3. Putty, or if you’re on Linux, SSH
4. Internet connection with both systems on the same network if you’re testing. Otherwise, you’ll just need internet for the online portion.

Online System Update, Upgrade, and Captures

Ok now let’s get to the interesting part. We start with the online system. In my case, I had an original image and a test box to play with. I won’t cover the uses of the “dd” command in this post, but that’s what I used to image my test drive. Once you get the system booted and ssh’d into, the first thing to do is to clear the archives.

Use the following to do so:

 apt-get clean

This cleans out all of the downloaded packages in the archives. This is a critical part as you’ll see later.

Next we’re going to edit the /etc/apt/sources.list. For this experiment, we were moving from Debian 8 (Jessie) to Stretch (9) as Buster (10) the current version is still too new. Now to edit, you can do this by hand using the editor of your choice. Mine is nano like so:

nano /etc/apt/sources.list

And you can replace each of the “jessie” words with “stretch”. Or if you want to save a bit of time you can try this sed code. If you want to change from stretch to buster for example just change the words as needed below.

sed -i 's/jessie/stretch/g' /etc/apt/sources.list;

All good? Good deal. Next, we’re going to do the normal song and dance we do to upgrade a Debian-based system. I like chaining commands and automating things a little bit, so I’m going to tell the apt system to update itself and its files (yes, this is important for something later on), and then I’m going to ask the system to proceed to upgrade itself.

apt-get update; apt-get upgrade -y;

You may wish to install what I call “generic system packages”. What I mean by that is these packages are part of the default repo’s found in the /etc/apt/sources.list. I didn’t need to add a key or another repository to get them. This is important because to run what I call “special packages”, as you’ll see, I need to do something else. We’ll get to that in a little further down. For now, we’ll run something generic like Java11.

apt-get install -y openjdk-11-jre openjdk-11-jre-headless openjdk-11-jdk openjdk-11-jdk-headless;

Now that we have that installed, it’s time to put our WinSCP into play. (As a Linux guy, I’m going to utter a curse…. Due to the simplicity of this, you might get Windows envy if you don’t have one to work with.)

I’m not going to go over WinSCP in this post, but it’s a fairly intuitive tool to use especially if you’ve ever used Putty before. Once you’ve created your scp or sftp connection through WinSCP, you should create a “dump” folder. I named mine “apt-offline” after a tool that was not useful to me at all.

Now for the difficult part. I’m joking. On the left is my Windows computer drive and on the right is the remote computer drive. So I’m going to do some clicking around where you see /tmp/ listed out. Specifically, I’m going to click on “/” because that takes me to the root directory. Where we need to go is:

/var/cache/apt

Once there, click on the “archives” folder. That’s where the meat is. Let’s drag the archives folder to the folder we set up and (hopefully) navigated to on our Windows computer. You will get errors on the “lock” file and the “partial” folder. That’s perfectly fine as we don’t need them.

Now we run:

apt-get clean

The archives directory will be empty now with the exception of the “lock” file and “partial” folder. Ok so remember when I said we’d cover what to do if we had a special case that required installing something additional that is not in the main repo’s? Well, I’m going to deliver on that promise here. To make this simple, I’m going to install “influxdb” which requires a key to be added and a repo and is NOT part of the main repo’s.

##Things I found I needed, we run slim systems
##Below could have been installed at time of the
##Java install
#apt-get install -y gnupg2 apt-transport-https ca-certificates curl software-properties-common;

##Now lets get installing. This is from the 
##InfluxDB install page for your reference :-)

wget -qO- https://repos.influxdata.com/influxdb.key | sudo apt-key add - ;
source /etc/os-release
test $VERSION_ID = "7" && echo "deb https://repos.influxdata.com/debian wheezy stable" | sudo tee /etc/apt/sources.list.d/influxdb.list
test $VERSION_ID = "8" && echo "deb https://repos.influxdata.com/debian jessie stable" | sudo tee /etc/apt/sources.list.d/influxdb.list
test $VERSION_ID = "9" && echo "deb https://repos.influxdata.com/debian stretch stable" | sudo tee /etc/apt/sources.list.d/influxdb.list

apt-get update; 
apt-get install -y influxdb;

Imagine everything installed. Now it’s time to check that treasure trove in archives and see what we got. This should have given us the .deb file and any other dependencies we didn’t know about.

In this case, I found all that had been downloaded was the “influxdb_1.7.9-1_amd64.deb” file. I’ll copy this over with WinSCP and place it with the other packages in the archives file, but NOT before I note the full name. I will use this when I run the dpkg script later on in the archives folder.

dpkg -i influxdb_1.7.9-1_amd64.deb;

Well, that wraps up this section of prep. In the next post, I’ll show you how you can put this into action.