Next we want to configure Tower so that we can run Ansible jobs. For this we need Inventories, Projects, Credentials and Job Templates. When you first start with Tower, this is usually done via web UI. But using Tower more often and especially when you want to boot-strap a configured Tower from the bottom up it makes sense to do this via awx in a scripted way - especially when Ansible is not yet set up properly.
In the first step you will learn to setup the inventory with awx step by step to get practice using the tool. For the following steps (Projects, Credentials, Job Templates) we will not go into such detail. Instead we will just explain the actual awx commands and put them all into a shell script. This shell script will serve as an example of how to bootstrap a Tower from bottom up.
First we create a static inventory, we’ll get to dynamic inventories later on. Try to figure out the proper invocation of awx yourself and create an inventory name Example Inventory.
Remember how you used the awx help to get down to the needed command.
[student@ansible-1 ~]$ awx -f human inventory create --name "Example Inventory" --organization "Default"
You can work with multiple organizations in Tower. In this lab we’ll work in the Default organization.
Now that we have the empty inventory created, add your two managed hosts using their internal hostnames node1 and node2, again using
awx.
[student@ansible-1 ~]$ awx -f human host create --name "node1" --inventory "Example Inventory"
[student@ansible-1 ~]$ awx -f human host create --name "node2" --inventory "Example Inventory"
As mentioned one of the purposes of awx is to use it to automatically configure more complex Tower setups. In such cases, multiple awx commands are put together in a script. We follow that practice in our example here, and create a shell script on the control host with all commands you have to run to bootstrap Tower. So in the next few paragraphs we describe the steps to do and describe the corresponding awx commands. But we will not execute them, but instead write them into a script.
In code-server create a new file File->New File and save it (File->Save As) as setup-tower.sh. Add the commands executed above:
#!/bin/bash
awx -f human inventory create --name "Example Inventory" --organization "Default"
awx -f human host create --name "node1" \
--inventory "Example Inventory"
awx -f human host create --name "node2" \
--inventory "Example Inventory"
You have run these commands above already, true. But we want to show how to create the full script here. You’ll get “Duplicate” messages because the objects already exist.
Next, save the script and make the script executable in the terminal window. Then launch it:
[student@ansible-1 ~]$ chmod u+x /home/student<N>/setup-tower.sh
[student@ansible-1 ~]$ /home/student<N>/setup-tower.sh
From now on we’ll explain the needed commands for each of the next steps and add them to the script one-by-one.
SSH keys have already been created and distributed in your lab environment and sudo has been setup on the managed hosts to allow password-less login. When you SSH into a host as user student<N> from ansible-1 you will become user ec2-user on the host you logged in.
Now we want to configure these credentials to access our managed hosts from Tower. Add the following to to setup-tower.sh, but don’t run the script yet:
awx -f human credential create --name "Example Credentials" \
--organization "Default" \
--credential_type "Machine" \
--inputs '{"username": "ec2-user", "ssh_key_data": "@~/.ssh/aws-private.pem"}'
Don’t run the shell script yet, first go through the following steps to add all commands to it.
As the awx commands get longer you’ll find we use the back-slash for line wraps to make the commands readable. You can copy the examples or use them without the \ in one line, of course.
The Ansible content used in this lab is hosted on Github. The next step is to add a project to import the playbooks. Add the appropriate awx command to the script setup-tower.sh:
awx -f human project create --name="Apache" \
--scm_type=git \
--scm_url="https://github.com/goetzrieger/ansible-labs-playbooks.git" \
--organization "Default" \
--scm_clean=true --scm_delete_on_update=true --scm_update_on_launch=true \
--wait
Note that the first parameter to awx is different here since we work on the resource project.
Before running an Ansible Job from your Tower cluster you must create a Job Template, again business as usual for Tower users. Here awx will work on the resource job_template. Add the following command to your script setup-tower.sh. Don’t run the script yet.
awx -f human job_templates create \
--name="Install Apache" \
--inventory="Example Inventory" \
--project=Apache \
--playbook=apache_install.yml \
--become_enabled="yes"
And finally we need to attach the credentials we created above to the Job Template. Add the following command to your script setup-tower.sh. Don’t run the script yet.
awx -f human job_template associate --name "Install Apache" \
--credential "Example Credentials"
Verify that your script has all the pieces needed to properly configure Tower:
inventory with hosts
machine credentials and credentials for Git
project
job template
The final script is also shown here:
#!/bin/bash
awx -f human inventory create --name "Example Inventory" --organization "Default"
awx -f human host create --name "node1" \
--inventory "Example Inventory"
awx -f human host create --name "node2" \
--inventory "Example Inventory"
awx -f human credential create --name "Example Credentials" \
--organization "Default" \
--credential_type "Machine" \
--inputs '{"username": "ec2-user", "ssh_key_data": "@~/.ssh/aws-private.pem"}'
awx -f human project create --name="Apache" \
--scm_type=git \
--scm_url="https://github.com/goetzrieger/ansible-labs-playbooks.git" \
--organization "Default" \
--scm_clean=true --scm_delete_on_update=true --scm_update_on_launch=true \
--wait
awx -f human job_templates create \
--name="Install Apache" \
--inventory="Example Inventory" \
--project=Apache \
--playbook=apache_install.yml \
--become_enabled="yes"
awx -f human job_template associate --name "Install Apache" \
--credential "Example Credentials"
And now: Run the script (make sure the TOWER_ environment variables are defined), and verify that all resources were properly created in the web UI.
It’s easy to script Tower’s configuration using awx. This way you can bootstrap a new Tower node or script tasks you have to run on a regular basis. You will learn more about the Tower API at the end of the lab.
We are working in a clustered environment. To verify that the resources were created on all instances properly, login to the other Tower nodes web UI’s (You run the awx commands against your Tower node 1).
Have a look around, everything we automatically configured on one Tower instance with our script was synchronized automatically to the other nodes. Inventory, credentials, projects, templates, all there.