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= LAB OBJECTIVES =
:0. Review SSH setup and remote shell execution:1. Use Explore the '''Fabric Python library and its command line tool "fab".:2. Create Fabric scripts utilizing Fabric''' program s API to execute administrative define tasks on remote host via Python functions under for the '''Fabricfab''' frameworkcommand.:23. Create python functions using Fabric API Use the '''fab''' command to execute fabric script to perform Linux system administrative pre-defined tasks on controlled remote Linux systemsmachines.
== Overview ==
: Completing this lab will give you Fabric is a taste Python library and command-line tool for streamlining the use of what is involved in automating remote SSH for application deployment or system/network administration tasks. It has two major components::# a command-line interface program called "fab" that lets you execute arbitrary Python functions :# a set of Python APIs that you can use and call in your Python functions to make executing shell commands over SSH much easier. : We will look at and are going use the Fabric API and its '''Fabricfab''' package command to define and execute Python functions (or tasks), to automate interactions with remote Linux machines in this lab. Using Fabric you can automate monitoring, deploying software, and updating many systems at the same time repeatedly.
== REFERENCE ==
| style="border: 2px solid black;" | Category
| style="border: 2px solid black;" | Resource Link
|- style="background-color:white;border:none;"
:[https://www.digitalocean.com/community/tutorials/how-to-use-fabric-to-automate-administration-tasks-and-deployments]
|- style="background-color:white;border:none;"
| style="border: 2px solid black;" valign="top"|
:Official '''Fabric''' website
| style="border: 2px solid black;" valign="top"|
:[http://www.fabfile.org/]
|}
: <font color='blue'>Please note that the version of Fabric installed on matrix.senecacollege.ca for this lab is 1.14 and it supports only Python version 2.</font> The Fabric script files we are going to create in this lab have to meet Python version 2.x requirements. (e.g. print is a keyword, not a built-in function in Python 2.x):2. You should have learned some experience on the following topics in OPS235 and or OPS335. Please review them to prepare for some of the tasks activities in this lab::* Configure create and allow configure a regular user to run the sudo commandon a Linux system. :* The man page on configure and manage sudoprivilege for a regular user:* Configure sudoers using the configuration file: /etc/sudoers.visudo command:* Managing critical system log files: /var/log/messagesusing the yum command to install, /var/log/maillogremove, /var/log/secureand update rpm packages
:* Retrieve current firewall setting using the iptables -L -n -v command
= INVESTIGATION 1: Extra VM Setup The Fabric Environment =
: In order to experience The Fabric environment consists of the following components: :# Controller workstation - the machine that has the Fabric package installed and runs the "fab" command:## the Fabric Python Library - the fabric package (already installed on matrix):## the Fabric API - fabric.api:## the Fabriccommand - '''fab''s features ': run Fabric script, name of the script is default to fabfile.py in a realistic way, wethe current working directory unless specified otherwise with the '-f're going option.:## Fabric script: contains fabric environment object value and Python functions (or tasks) to set up several virtual machines (You need at least be executed by the '''fab''' command.:# Remote machine: the target machine on which one or more VM)Fabric tasks will be executed. To begin with they are all going to have :## running the same configuration. Please make sure that each VM has direct network ssh server daemon:## use public key (or password based) authentication for ssh connection with other VMs you wish to control and configure.
== PART 1 - Set up Configure and test your controller workstation ==: In this lab you will use your login account on matrix.senecacollege.ca as your Fabric controller workstation.
: In this lab you will use your existing vm The Fabric package version 1.14.0 has already been installed on matrix.senecacollege.ca. You should have access to the '''centos7fab''' as a workstation command on matrix. Login to control other VMs which we'll call workersmatrix.senecacollege. Later in ca and run the lab, we will try following command to control and monitor your vm in myvmlab using confirm the version of the fabfile we are going to develop. fabric package: Install '''fabric''' using yum. Once it's installed you should have a '<source lang='bash'>fab''' command available. --version</source>: Type the following command to get the command line optionoptions of the fab command:<source lang='bash'>
fab --help
</source>
:You should get something similar to the following:<source lang="bash">
Usage: fab [options] <command>[:arg1,arg2=val2,host=foo,hosts='h1;h2',...] ...
number of concurrent processes to use in parallel mode
</source>
<font color='green'><b>Please note and study the following command-line options as they will be used in some of the activities in this lab::# -H, :# -f, :# -i, :# -l, and :# --port options.:# --user:# --initial-sudo-password-prompt </b></font>
== PART 2 : Connect to VM in myvmlab.senecacollege.ca ==: You should have received an email from ITS containing the following information::* account name: (usually 'student'):* password: (let's assume it is 'P@ssw0rd' for the following instruction in this lab):* port number for SSH access via myvmlab.senecacollege.ca (e.g. 7200): This VM will be used as the remote Linux machine in our Fabric environment. Login to matrix and try the following SSH command to test the connectivity between matrix and your assignment VM:<pre> [raymond.chan@mtrx-node05pd lab8]$ ssh -p 7200 student@myvmlab.senecacollege.ca student@myvmlab.senecacollege.ca's password: Last login: Fri Jul 3 11:06:24 2020 from mtrx-node05pd.dcm.senecacollege.ca</pre>: Once you are on your VM, try the following commands: hostname, id, and df, and record the results for later comparison with the results of other commands:<source lang='bash'>[student@centos7 ~]$ hostnamecentos7[student@centos7 ~]$ iduid=1002(student) gid=1002(student) groups=1002(student),10(wheel)[student@centos7 ~]$ dfFilesystem 1K-blocks Used Available Use% Mounted ondevtmpfs 878260 0 878260 0% /devtmpfs 889792 0 889792 0% /dev/shmtmpfs 889792 9492 880300 2% /runtmpfs 889792 0 889792 0% /sys/fs/cgroup/dev/mapper/centos- Create master Worker image root 38680112 1745524 36934588 5% //dev/sda2 1038336 331228 707108 32% /boot/dev/sda1 204580 11296 193284 6% /boot/efi/dev/mapper/centos-home 18880512 33160 18847352 1% /hometmpfs 177960 0 177960 0% /run/user/1002</source>:Logout from your VM and get back to matrix.:The previous SSH command when executed successfully, created a login shell on the remote machine. If the previous SSH command is followed by a specific bash command, it will be executed on the remote host instead of creating a login shell. Consider the following:<source lang='bash'>[raymond.chan@mtrx-node05pd lab8]$ ssh -p 7200 student@myvmlab.senecacollege.ca 'hostname;id;df'student@myvmlab.senecacollege.ca's password:centos7uid=1002(student) gid=1002(student) groups=1002(student),10(wheel)Filesystem 1K-blocks Used Available Use% Mounted ondevtmpfs 878260 0 878260 0% /devtmpfs 889792 0 889792 0% /dev/shmtmpfs 889792 9492 880300 2% /runtmpfs 889792 0 889792 0% /sys/fs/cgroup/dev/mapper/centos-root 38680112 1745608 36934504 5% //dev/sda2 1038336 331228 707108 32% /boot/dev/sda1 204580 11296 193284 6% /boot/efi/dev/mapper/centos-home 18880512 33160 18847352 1% /hometmpfs 177960 0 177960 0% /run/user/1002</source>:The three shell commands: hostname, id, and df were executed sequentially. Compare the outputs above with the previous results when executing the corresponding commands in the login shell.:Please note that you were asked to provide the user's password for every SSH connection.
==PART 3: Create a new virtual machineSet up SSH login with public key authentication ==: In order for your controller workstation to automate tasks execution on your VM, you need to configure your VM to SSH public key authentication instead of password authentication. You've done this in both OPS235 and OPS335, and allocate for here is a summary on how to do it 1GB of RAM between your account on matrix and 8GB of disk space. Install a Basic Web Server configuration of CentOS in that your VM using the same CentOS .iso file you used for your first machine in this course.:
: Make sure that::* The hostname of the system is '''worker1'''.:* It has Create a static IP address appropriate for new SSH key pair (one private, and one public) under your virtual networkaccount on matrix.senecacollege.:* Create a regular user using your Seneca email name as the user name: [seneca_id]ca. :* Add this new regular user to Once you have both keys, you can use the '''wheelssh-copy-id''' group using command to copy your public key to the student account on your VM, replace the port number with the following commandcorrect value for your VM:<source lang="'bash"'> usermod ssh-copy-id -a i ~/.ssh/id_rsa.pub -G wheel [seneca_id]p 7200 student@myvmlab.senecacollege.ca</source>This will allow : The above command should add the user contents of your pub key to run the '''sudo''' command~/.ssh/authorized_keys under your student account on your VM.:* After installation ensure Verify and confirm that you your account on matrix can access SSH to your VM as 'student'without prompting for a password:<source lang='worker1''bash' >[raymond.chan@mtrx-node05pd lab8]$ ssh -p 7200 student@myvmlab.senecacollege.caLast login: Fri Jul 3 12:46:19 2020 from your main vm using the static IP address you've assigned mtrx-node05pd.dcm.senecacollege.ca[student@centos7 ~]$ exitlogoutConnection to itmyvmlab.senecacollege.ca closed.
[raymond.chan@mtrx-node05pd lab8]$ ssh -p 7200 student@myvmlab.senecacollege.ca 'date;hostname;id'Fri Jul 3 12:55:22 EDT 2020centos7uid=1002(student) gid=1002(student) groups= Set up SSH key login ===1002(student),10(wheel)[raymond.chan@mtrx-node05pd lab8]$</source>: In order for an automated system to be able to connect to If you got similar result as above, you have successfully configure your controller workstation and your VM and administer it - you will need to be able to connect to it using SSH keys. You've done this in both OPS235 and OPS335use public key authentication.
=INVESTIGATION 2 - Running the fab command in ad-hoc mode =: Create a new The fab command relies on SSH to make the connection to the remote machine before executing the intended commands. The fab command can run in ad-hoc mode:<source lang='bash'>fab [options] -- [shell commands]</source>: When running the fab command in ad-hoc mode, it is very similar to running the SSH key on your main VM with your regular usercommands attached at the end. Please do not == PART 1: running non-privileged shell commands on remote machines ==: In the following example, we use root. Then set things up so that your regular user on your the '''controller VMfab''' can SSH to execute the worker "date", "hostname", and "id" command remotely on our VM as . Try the same regular following ad-hoc fab commands and record their results for later use, replace the port number with the correct value for your VM:<source lang='bash'>[raymond.chan@mtrx-node05pd lab8]$ fab --host=myvmlab.senecacollege.ca --port=7200 --user without prompting for a password=student -- 'date;hostname;id'[myvmlab.senecacollege.ca] Executing task '<remainder>'[myvmlab.senecacollege.ca] run: date;hostname;id[myvmlab.senecacollege.ca] out: Fri Jul 3 13:05:39 EDT 2020[myvmlab.senecacollege.ca] out: centos7[myvmlab.senecacollege.ca] out: uid=1002(student) gid=1002(student) groups=1002(student),10(wheel)[myvmlab.senecacollege.ca] out:
Done.Disconnecting from myvmlab.senecacollege.ca:7200... done.[raymond.chan@mtrx-node05pd lab8]$</source>: '''** Optional **''' Make four clones of Note that there is no password prompting if you complete part 3 successfully, otherwise, the master worker image SSH server daemon on your VM will prompt you've just created. Then make sure that each of them has for a unique IP addresspassword. ThatThe output from the fab's all you're required to change manually. All ad-hoc mode is not much different from the SSH command with shell command attached at the end, however, please note that the other configuration additional information on the workers (inlcuding output from the hostnames) will fab command can be set by Fabric. Normally you would have some kind of automation doing all this cloning very useful for record keeping purpose - what has been done and IP address assignment as well, but we don't have time for that this semesterwhether the commands had been carried out successfully or not.
== PART 2: Make snapshots of all your workers so running privileged commands on remote machines ==: We say that you can easily restore them running an ad-hoc fab command is very similar to the original state after you modify themSSH command with shell commands attached at the end. Let's try both with privileged commands, like the "yum" command.
= INVESTIGATION 2: Fabric practice == Run the "yum" command on remote machine with SSH ===: We will start with some basics. Fabric runs python programs on By default, your VM doesn't have the controller and the workers"tree" rpm package installed. You create an "instruction" file on your controller, and execute it on can verify this with the following SSH command (remember to replace the controller using port number with the correct value for your VM):<source lang='bash''fab''' program>[raymond. When you do that chan@mtrx-node05pd lab8]$ ssh - you specify which workers you want your instructions to be executed onp 7200 student@myvmlab.senecacollege.ca "yum list tree"Loaded plugins: fastestmirrorLoading mirror speeds from cached hostfile * base: The instructions are stored in a python filecentos. Let's start with a simple one named '''fabfilemirror.colo-serv.net * extras: centos.mirror.colo-serv.py''' (the default filename for fab)net * updates:centos.mirror.ca.planethoster.netAvailable Packages== PART tree.x86_64 1: Simplest example ==.6.0-10.el7 base[raymond.chan@mtrx-node05pd lab8]$: </source lang=>: Please note that the tree package is "pythonAvailable">from fabric, but not yet installed.api import * # Will get : Let't try to install the "tree" package with the hostname of this workershell command "yum install tree -y":<source lang='bash'>def getHostname(): name = run([raymond.chan@mtrx-node05pd lab8]$ ssh -p student@myvmlab.senecacollege.ca "hostnameyum install tree -y") print(name)Loaded plugins: fastestmirrorYou need to be root to perform this command.
</source>
: Using the "yum" command to query rpm package doesn't need special privilege, however, it does when you try to install or remove rpm packages.
: Your "student" account on your VM was configured to allow you to run the "sudo" command to perform software management using the "yum" command. Let's login to your VM and try the following "sudo" command to install and then remove the "tree" rpm package:<source lang='bash'>
[raymond.chan@mtrx-node05pd lab8]$ ssh -p 7200 student@myvmlab.senecacollege.ca
Last login: Fri Jul 3 16:51:07 2020 from mtrx-node05pd.dcm.senecacollege.ca
[student@centos7 ~]$ sudo yum install tree -y
[sudo] password for student:
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: less.cogeco.net
* extras: centos.mirror.colo-serv.net
* updates: mirror.calgah.com
Resolving Dependencies
--> Running transaction check
---> Package tree.x86_64 0:1.6.0-10.el7 will be installed
--> Finished Dependency Resolution
Total download size: If you did all the setup right and you try to execute the command above 46 kInstalled size: 87 kDownloading packages:tree-1.6.0- you will get a password prompt10. Read the prompt carefully and see who's password it prompts youel7. If it is not the same as your [seneca_id], try to fix it by adding the following line to before the first '''def''' line your fab filex86_64.rpm | 46 kB 00:00:00Running transaction checkRunning transaction testTransaction test succeededRunning transaction Installing : tree-1.6.0-10.el7.x86_64 1/1 Verifying : tree-1.6.0-10.el7.x86_64 1/1
Installed:<source lang="python">env tree.user = '[seneca_id]'</source>x86_64 0:1.6.0-10.el7
Complete![student@centos7 ~]$</source>:That should have workedPlease note that when you run the "sudo" command the first time, and it asks youfor the user's password (i.e. user student's password). Let's now remote the "tree" package:<source lang='bash'd get output like >[student@centos7 ~]$ yum remove tree -yLoaded plugins: fastestmirrorYou need to be root to perform thiscommand.[student@centos7 ~]$ sudo yum remove tree -yLoaded plugins: fastestmirrorResolving Dependencies--> Running transaction check---> Package tree.x86_64 0:1.6.0-10.el7 will be erased--> Finished Dependency Resolution
Installed size: In the above you have87 kDownloading packages::* Lines with an IP address telling you which worker the output is for/from.Running transaction checkRunning transaction testTransaction test succeededRunning transaction Erasing :* Messages from the controller (etree-1.g6. "Executing task0-10.el7..", and "runx86_64 1/1 Verifying : tree-1.6.0-10.")el7.:* Output from the worker ("out: ..."):* Output on the controller from your fab file ("worker1" which came from the "print()" call)x86_64 1/1
Removed:You should get used to the above tree. It's a lot of output but it's important to understand where every part is coming from, so you are able to debug problems when they happenx86_64 0:1.6.0-10.el7
Complete![student@centos7 ~]$</source>: The above tests confirm that the student user is allowed to run the yum command to install and remove rpm package. Now let's logout from the VM and go back to matrix. On matrix, try to run the sudo command using SSH:<source lang== Part 2'bash'>[student@centos7 ~]$ exitlogoutConnection to myvmlab.senecacollege.ca closed.[raymond.chan@mtrx-node05pd lab8]$ ssh -p 7211 student@myvmlab.senecacollege.ca "sudo yum install tree -y"sudo: no tty present and no askpass program specified[raymond.chan@mtrx-node05pd lab8]$</source>: Set The above error indicated that you need a tty for the SSH session to prompt you for the sudo password. Please look up web server ==the ssh man page to find out the option which turn on a tty for the SSH session.
=== Run the privileged yum command on remote machine using ad-hoc fab command ===:Let's pretend that we needed to deploy a web server try the corresponding ad-hoc fab command on several machines. Weyour VM:<source lang='bash'll set up a simple example of such a deployment here.>fab --host=myvmlab.senecacollege.ca --port=7200 --user= Install Apache ===student -- 'sudo yum install tree -y'</source>:Add a setupWebServer() function Type in your user student's password when prompted for "sudo password", the yum install command to your python file: install the tree rpm package should be executed successfully. If the tree rpm package is already installed, you can remove it with the following ad-hoc fab command:<source lang="python"'bash'># Will set up a working web server with a prefab --host=myvmlab.senecacollege.ca --port=7200 --user=student -built websitedef setupWebServer(): run("hostnamectl set-hostname www") run("'sudo yum install httpd") run("systemctl enable httpd") run("systemctl start httpd")remove tree -y'
</source>
: Try remove the "tree" rpm package with the appropriate ad-hoc fab command.
= INVESTIGATION 3:Note Running the fab command in script mode =: From investigation 2, we can see that each call running '''fab''' in ad-hoc mode is quick, straight forward, and easy. However, the rich output generated can not be easily captured and processed. If you have a need to capture and process the output generated by the commands executed on the remote machines, the solution is to "run()" will run a the '''fab''' command on in script mode.: The first step in running the worker'''fab''' command in script mode is to create a fabric script file. In this function we set : Let's start with a simple fabric script file to demonstrate some basic concepts that use the hostname of API from the machine Fabric python library.: On matrix, cd to "www", install Apache, enable the Apache service, your lab8 directory and start that service now. Pretty create a simple commandsfabric script file named '''fabfile.py''' (this is the default filename used by the fab command when you invoke it without the '-f' optino):
== PART 1:If you try Non-privileged task example =====Create non-privileged tasks: Getting the hostname of remote machines===: Add the following contents to run it the same way as beforedefault fabric script called "fabfile.py" in your lab8 directory:<source lang="python">from fabric.api import *
# Define the task to get the hostname of remote machines:You'll find that yum prompts you to answer questions, which you don't want to do in an automated environment. And also yum prints too much output, which also isn't helpful in an automated environment. We'll fix it by adding two switches to yumdef getHostname(): name = run("-yhostname" and ) print("-d1The host name is:":,name)</source>
:Notice also that all of To check for syntax error in the four commands can be fabric script, run as many times as you want, the result will be following command in the lab8 directory where it contains the samefabric script named "fabfile. This is not always so easypy":<source lang="bash">fab -l</source>: you should get a list of tasks defined in your fabfile.py:<source lang="bash">[rchan@centos7 lab8]$ fab -lAvailable commands:
getHostname</source>:At this point if you log in To perform the task of getHostname on your VM (replace with the actual port # for connecting to worker1 - you should see a new hostnameyour VM), and httpd installed and running (try with run the fab command on matrix:<source lang="systemctl statusbash")>[raymond.chan@mtrx-node05pd lab8]$ fab --hosts=myvmlab.senecacollege.ca --port=7200 getHostname[myvmlab.senecacollege.ca] Executing task 'getHostname'[myvmlab.senecacollege.ca] run: hostname[myvmlab.senecacollege.ca] out: centos7[myvmlab.senecacollege.ca] out:
</source>
: Notice that there is no need to specify the user name at the '''fab''' command line since we defined it in the fabric script file (env.user = 'student'). Also notice that we can capture the host name returned from the "hostname" command and print it out together with an descriptive text in a line.
:There is something weird in In the code above that you havenexecuted 't seen before but it's required for some uses of Fabric: the 'fab''with''' statementcommand, the fab program imports the fabric script named "fabfile.py" and execute the getHostname function on the VM connect at port 7200 on myvmlab.senecacollege.ca. Note that the port number for your first will likely be of a different value.
:The problem is that separate '''run''' commands each If you did all the setup right and you got a password prompt when execute in a brand new sessionthe above command, each with its own shellread the prompt carefully and see who's password it was prompting you for. They are If it is not like separate lines for the user student, verify that you have the following line in a single shell script even though they look like they should beyour fabfile.py and you can ssh to your VM as the user student without password:
:That means if you run a cd command and then a tar command separately - the tar command will not run in the directory where you think it will<source lang="python">env. In order to fix this you have to nest commands inside a user = 'student''with''' - it's like a '''run''' but with persistant results.</source>
:The code we added to In the function will cd to above output from the '''fab''' command, you have::* Lines with the FQDN of the default web site directory remote machine you are working on .:* Messages from the workercontroller workstation (e.g. "Executing task...", upload your web contents tarball and "run: ...").:* Output from your controller to that directory the remote machine ("out: ..."):* Output generated on the worker, extract it, and delete controller workstation from your fab file (the tarball.print statement)
:After You should get used to the above messages from the '''fab''' command. It's a lot of output but it's done - important to understand where every part is coming from, so you should have a working web server and simple website on your worker1are able to debug problems when they happen.
== PART 2:Except you won't be able Privileged Tasks Examples =====Creat privileged tasks: install and remove rpm package on remote machines===: Add the following two new functions to access it because the end of the firewallfabric script "fabfile. Wepy" in your lab8 directory:<source lang='ll deal with that in the next section.bash'>
def installPackage(pkg== Part 2'dummy'): Set up the firewall cmd ='yum install ' + pkg + ' -y' status =sudo(cmd) print(status)
def removePackage(pkg): Recall if pkg == '': cmd = 'yum remove dummy -y' else: cmd = 'yum remove ' + pkg + ' -y' status = sudo(cmd) print(status)</source>: Note that both functions take one function argument in our OPS courses we've been using iptables instead of firewallddifferent ways. However, which if no function argument is installed by passed when calling the function, both will default to a string value of "dummy". Both functions call the sudo() from the fabric.api to execute the command contained in CentOSthe "cmd" object on the remote machine via sudo. Let's make sure that our workers have that set up : To check for any syntax error in your updated fabric script, run the following command in the same directory as well. In the same '''fabfile.py:<source lang='bash'>fab -l</source>: You should get a list of tasks defined similar to the following:<source lang=' youbash've been using all along, add a new function like this>[raymond.chan@mtrx-node05pd lab8]$ fab -lAvailable commands:
</source>
: If you only need to connect to the same remote machine, you can specify the host and port number in the fabfile.py to save some typing when executing the fab command. Add the following two lines after the env.user line in your fabfile.py:<source lang='bash'>
env.port = '7200' # <-- please replace with the actual value of your VM's port number
env.hosts =['myvmlab.senecacollege.ca']
</source>
: You can also store the user's password in this file so that it will respond to the "sudo password" prompt for sudo() call. It is not safe to do so as you can configure the sudo module on the remote machine not to ask for sudo password.
: Now you can run the fab command without the "--host" and "--port" option.
: Run the following two fab commands, note the results and compare their difference:<source lang='bash'>
fab installPackage
fab installPackage: That should by now look prett obvious. On tree</source>: Run the worker you're going to uninstall firewalld, install iptablesfollowing two fab commands, note the results and make sure that the iptables service is running.compare their difference:<source lang='bash'>fab removePackage
fab removePackage: Execute the function for worker1 and double-check that it worked.tree</source>
==Part 2: Create remote task for updating rpm packages = Allow access =: Add a new function called "updatePackage" to your fabfile.py according to Apache through the firewall =following requirements::* Accept optional function argument as the rpm package name:* If no function argument was given when called, default to all the packages installed: The output of the updatePackage when executed, should produce similar output as shown below::1. Update a single package:<source lang='bash'>fab updatePackage:tree</source>: Sample output:<source lang='bash'>[raymond.chan@mtrx-node05pd lab8]$ fab updatePackage:tree[myvmlab.senecacollege.ca] Executing task 'updatePackage'[myvmlab.senecacollege.ca] sudo: yum update tree -y[myvmlab.senecacollege.ca] out: sudo password:[myvmlab.senecacollege.ca] out: Loaded plugins: fastestmirror[myvmlab.senecacollege.ca] out: Loading mirror speeds from cached hostfile[myvmlab.senecacollege.ca] out: * base: less.cogeco.net[myvmlab.senecacollege.ca] out: * extras: centos.mirror.ca.planethoster.net[myvmlab.senecacollege.ca] out: * updates: less.cogeco.net[myvmlab.senecacollege.ca] out: No packages marked for update[myvmlab.senecacollege.ca] out:
Loaded plugins: The default setup of iptables also doesn't allow access to our web serverfastestmirrorLoading mirror speeds from cached hostfile * base: less.cogeco.net * extras: centos.mirror.ca. We'll need to add some more to our function to allow itplanethoster. This would probably make more sense in setupWebServer() but net * updates: less.cogeco.netNo packages marked for now let's put it into setupFirewall():update
Done.Disconnecting from myvmlab.senecacollege.ca: <source lang="python"> run("iptables -I INPUT -p tcp --dport 80 -j ACCEPT")7200... done. run("iptables[raymond.chan@mtrx-save > /etc/sysconfig/iptables")node05pd lab8]$
</source>
</source>
: The following output had been trimmed, only showing the first few lines:<source lang='bash'>
[myvmlab.senecacollege.ca] Executing task 'updatePackage'
[myvmlab.senecacollege.ca] sudo: yum update -y
[myvmlab.senecacollege.ca] out: sudo password:
[myvmlab.senecacollege.ca] out: Loaded plugins: fastestmirror
[myvmlab.senecacollege.ca] out: Loading mirror speeds from cached hostfile
[myvmlab.senecacollege.ca] out: * base: less.cogeco.net
[myvmlab.senecacollege.ca] out: * extras: centos.mirror.ca.planethoster.net
[myvmlab.senecacollege.ca] out: * updates: less.cogeco.net
...
Verifying : Test your new setupFirewall function on worker1, and make sure it opens access to Apache but does not create duplicate rules every time it's runsystemd-219-73.el7_8.5.x86_64 53/54 Verifying : systemd-libs-219-73.el7_8.5.x86_64 54/54
Installed: After completing all the previous parts of the lab kernel.x86_64 0:3.10.0- you should have a working fabfile1127.py with two working functions: setupFirewall() and setupWebServer()13.1.el7
= Final Task - Apply fabfile.py to your VM on myvmlab Lab Exercise: Create a Fabric task called makeUser() =: Since your account on your vm on myvmlab is a regular user with Study the Fabric API run(), sudo privilege. You need (), and put() and utilize them to make create a new task called makeUser(): The makeUser() function should perform the following changes to your fabfile.py before applying it to your vm on myvmlab::* Change envcreate a new user called "ops435p" with home directory "/home/ops435p".user from 'root' :* add it to your account on your vm in myvmlabthe sudo group called "wheel".:* Change all ask your professor for a ssh public key and add it to the file named "authorized_keys" in the commands ~ops435p/.ssh directory. Make sure that need super user privilege from calling you set the proper permissions on both the run() function to instead calling directory ~ops435p/.ssh and the sudo() functionfile "~ops435p/.ssh/authorized_keys.: Test Add the makeUser() to your updated final version of fabfile.py until you get . :Run the same result as when you apply it to new task makeUser() on your own worker VM.:Verify and confirm that your new makeUser() task is working correctly.
= LAB 8 SIGN-OFF (SHOW INSTRUCTOR) =
:'''Have Ready to Show Your Instructor:'''* Complete all the parts of the lab and show upload the version of your fabfile.py which works on your vm on myvmlabto Blackboard by the due date. = LAB REVIEW =
[[Category:OPS435-Python]][[Category:rchan]]
