This article shows how to install the AWS SSM Agent on Fedora CoreOS. My goal was to alert when ‘denied’ messages appear in audit logs. My first step towards this goal was to install the SSM agent to allow the server’s /var/log/audit/audit.log file to appear in the CloudWatch Logs console.

After I did this work, I realized that I should have started with the CloudWatch agent. Ah well.

The first step is entirely in your hands. Clone https://github.com/aws/amazon-ssm-agent.git and build the binary files. Whatever directory you use will become the ssm_binary_dir in the ansible command.

The ansible-playbook command looks like this. core is the ssh user for Fedora CoreOS.

python3 ansible-playbook \
  --extra-vars ssm_binary_dir=/data/projects/amazon-ssm-agent/bin \
  -i inventory \
  -u core \
  playbook.harden.yml

Define an inventory file with the IP address of the remote server.

cat <<EOF > inventory
[fcos]
5.235.160.104
EOF

I add the PEM file to SSH to simplify my life. I learned that having PEM files in ~/.ssh slows the connection process and can cause trouble if there are too many. That’s I am using my Downloads directory.

ssh-add /home/medined/Downloads/ec2-key-pair.pem

Now here is the playbook.

cat <<EOF > playbook.aws-ssm-agent.yml
---
- hosts: fcos
  gather_facts: false

  vars:
    ansible_python_interpreter: '/usr/bin/python3'

  tasks:

  # ##########
  # # Amazon SSM Agent
  # ##########

  - name: Copy Amazon SSM Agent
    become: yes
    copy:
      src: ""
      dest: /usr/local/bin
      mode: 755
      force: no
    with_fileglob:
      - "/linux_amd64/*"

  - name: Make logging directory
    become: yes
    file:
      path: /var/log/amazon/ssm
      state: directory

  - name: Make config directory
    become: yes
    file:
      path: /etc/amazon/ssm
      state: directory

  - name: Copy Amazon SSM Agent JSON
    become: yes
    copy:
      src: "/amazon-ssm-agent.json.template"
      dest: /etc/amazon/ssm/amazon-ssm-agent.json

  - name: Copy Amazon SSM Agent JSON
    become: yes
    copy:
      src: "/seelog_unix.xml"
      dest: /etc/amazon/ssm

  - name: Create SSM service file.
    become: yes
    copy:
      dest: /etc/systemd/system/amazon-ssm-agent.service
      content: |
        [Unit]
        Description=amazon-ssm-agent
        [Service]
        Type=simple
        WorkingDirectory=/usr/local/bin
        ExecStart=/usr/local/bin/amazon-ssm-agent
        KillMode=process
        Restart=on-failure
        RestartSec=15min
        [Install]
        WantedBy=network-online.target

  - name: Enable SSM service
    become: yes
    service:
      name: amazon-ssm-agent
      enabled: yes
      state: started
EOF

You now have all of the pieces to deploy the AWS SSM Agent on Fedora CoreOS.