The order of precedence is command line parameters and then environment variables. RUN \ You can install all of these from the standard repositories via yum: The first step in this workflow is building an actual container image. The inventory file is typically named hosts and is stored in the Ansible project directory. RUN mkdir /etc/ansible /ansible Note: This is a gentle reminder to be mindful of your indentations. This way, you can share your playbooks as much as you want without sharing your secrets. # Makes the Ansible directories Separated as bundles, these containers have their own libraries and configuration files and they communicate with each other through well-defined channels. Get the highlights in your inbox every week. This command lists all (-a) the running and stopped containers on the server. We are following a specific directory structure to manage our Dockerfiles, playbooks, inventory, etc. Take a free technical overview course from Red Hat. py-pip \ Recommended Resources for Training, Information Security, Automation, and more! More about me. Ansible has a number of built-in modules and plugins, which makes it easy to perform complex tasks using simple YAML code. A playbook is a YAML file that defines a set of tasks to be carried out on managed hosts. Its dynamic How do I loop over a list of hosts in a group, inside of a template? Please upgrade to a maintained version. docker-build - This server is used to build Docker containers. Your output doesnt have to be exactly the same, but it is important that you have zero failures. If you run into an error, this is very likely the culprit. If you decide to change these in the future, you will only have to edit these single lines in your file. Why not use this newfound knowledge to deploy your applications on other cloud providers, such as Amazon Web Services (AWS) and Google Cloud Platform (GCP)? The SUCCESS messages indicate that the hosts are running. Common Styles and Usage, and Common Mistakes, 7. Note that YML is indent-sensitive, so be sure to paste the code as is to the playbook.yml file. Heres how to use it in playbooks to improve automation workflow safety. Red Hat and the Red Hat logo are trademarks of Red Hat, Inc., registered in the United States and other countries. Set up your playbook once, and use it for every installation after. YAML suggests using 2 spaces as an indent, as was done in this example. Join our DigitalOcean community of over a million developers for free! FROM alpine:3.7. As you can see below, the managed hosts are reachable as Ansible can connect to them. To connect to a single Docker API the following variables can be defined in the environment to control the connection Ansible uses YAML language in the form of playbooks. The Docker GPG key is added to verify the download, the official repository is added as a new package source, and Docker will be installed. RUN \ Im sticking with version 3.7 as Ive tested that. Editor's note: This article covers utilizing the Ansibledocker_image module for working with containers. creating a docker.yml file (sample provided in ansible/contrib/inventory). How do I keep secret data in my playbook? Get help and share knowledge in our Questions & Answers section, find tutorials and tools that will help you grow as a developer and scale your project or business, and subscribe to topics of interest. , Posted: This playbook copies the tarball created in the save.yml playbook to all of the Docker hosts. to launch your docker-compose file on OpenShift. Containers have taken over DevOps processes for good. When the playbook is finished running, log in via SSH to the server provisioned by Ansible to check if the containers were successfully created. py-yaml \ Building container images and placing them into upstream repositories is a common way of making your images available to the outside world. >Alpine is a lightweight version of Linux that is used as the core of this Docker image. | How do I configure a jump host to access servers that I have no direct access to? Since the playbook file (playbook.yml) is encrypted, youll have to append the --ask-vault-pass option to ask for the vault password. Further, we are creating containers to deploy a sample Drupal application on a remote server using Ansible from our local system. How do I access shell environment variables? Your playbook should look roughly like the following, with minor differences depending on your customizations: Feel free to modify this playbook to best suit your individual needs within your own workflow. > Using run and apk to install the Ansible dependencies, curl (to get Ansible from the web), a shell (just in case), tar (to decompress the installer later) and pip. See the latest ideas and thinking at the Ansible proposal repo. Finally, run the below command with the ping module to verify that Ansible can connect to your managed hosts. Avoid redundant prepositional phrases. The docker_service module also requires docker-compose, You can connect to a local or remote API using parameters passed to each task or by setting environment variables. But not to the point youre also sharing sensitive information, such as passwords and API keys. Once you have all prerequisites set up on your system, you can begin running playbooks. py-boto \ Note that creating a hosts file in the /etc/ansible directory requires sudo access. Run the below ansible-inventory command to verify that the inventory file (hosts) was created correctly. For example, you could use the docker_image module to push images to Docker Hub or the docker_container module to set up container networks. Ansible and Docker offer a flexible and efficient way to deploy software applications in portable containers with a playbook. I'm a tech enthusiast that enjoys science, science fiction, comics and video games - pretty much anything geeky. pip install upgrade pip. You can orchestrate and manage more complex containerized environments using Ansibmale, like Docker Swarm based environments as well. # apk add installs the following Related:How to Secure Ansible Playbooks with Ansible Become. The random string of characters at the end of the file is the encrypted version of the playbook. The managed hosts must be reachable over SSH using the key pairs you set up in the Prerequisites section. You can also override the default name of the script by defining DOCKER_CONFIG_FILE in the environment. You are reading an unmaintained version of the Ansible documentation. ENV ANSIBLE_GATHERING smart When should I use {{ }}? Thus, Ansible covers the full environment, from local machines to full cloud infrastructures. py-dateutil \ # Extracts Ansible from the tar file OUR BEST CONTENT, DELIVERED TO YOUR INBOX. hosts declares which servers the Ansible control node will target with this playbook. # Simple playbook to invoke with the above example: The URL or Unix socket path used to connect to the Docker API. python \ Youll write a playbook that deploys a basic Docker container on your managed hosts. Get the latest on Ansible, Red Hat Enterprise Linux, OpenShift, and more from our virtual event on demand. In addition to the connection variables there are a couple variables used to control the execution and output of the What is the best way to make content reusable/redistributable? tutorials by Nicholas Xuan Nguyen! Applying when to roles, imports, and includes, Selecting Files And Templates Based On Variables, Delegation, Rolling Updates, and Local Actions, Setting the Environment (and Working With Proxies), Working With Language-Specific Version Managers, Operating System and Distribution Variance. 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Running the Playbook to Deploy Ansible Docker Container, How to Install Ubuntu 20.04 [Step-by-Step], How to Leverage Ansible Variables in Roles and Playbooks, Leverage SSH and PowerShell to Securely Transfer Files Now, How to Build (And Actually Understand) a Solid Ansible Playbook, How to Secure Ansible Playbooks with Ansible Become. inventory by connecting to one or many Docker APIs and inspecting the containers it finds at each API. openssh-client \ Read more This article walks you through some simple playbooks that you can incorporate into your workflow to manage containers with Ansible. following: Still using Dockerfile to build images? 2. Ansible offers the following modules for orchestrating Docker containers: Ansible 2.1.0 includes major updates to the Docker modules, marking the start of a project to create a complete and ENV ANSIBLE_RETRY_FILES_ENABLED False Lets dig into the core of these two technologies/tools and learn how to utilize them. Spelling - Word Usage - Common Words and Phrases to Use and Avoid, 7.24. The script will create the following host groups: You can run the script interactively from the command line or pass it as the inventory to a playbook. We'd like to help. devops, This is a very simple Dockerfile to build an image for an NGINX web server. Working on improving health and education, reducing inequality, and spurring economic growth? A Linux machine (Ansible control node) This tutorial uses Ubuntu 20.04, but any modern Linux distribution will work. With the distributed nature of modern applications and the need for consistency between different staging environments, automation like this has become a central component in many teams development processes. Containers from build01 are uploaded and made available to both of these hosts. Unmaintained Ansible versions can contain unfixed security vulnerabilities (CVE). YAML files can be particular with their indentation structure, so you may want to double-check your playbook once youve added all your tasks. How can I improve performance for network playbooks? Support ATA Learning with ATA Guidebook PDF eBooks available offline and with no ads! > Overriding the key checking of SSH FOR PRODUCTION ENVIRONMENTS ANOTHER SOLUTION WILL BE NEEDED. The default values are provided under Inventory files can be in one of two formats, INI or YAML. Heres a brief explanation of each variable: Note: If you want to see the playbook file in its final finished state, jump to Step 5. Also, note that themysql_root_passvariable value is encrypted using Ansible vault. Go from an app on your laptop to a fully How To Get Started With Azure DevOps in 2022, Decouple, Containerize And Orchestrate Mautic On k8s, How to Handle Long Running Tasks In Ansible, beginner's guide to Docker and Kubernetes, Ansible 2.4 or higher installed and running on your local machine, Passwordless SSH connection between your local machine and remote server. This optimized and highly efficient standard unit of software empowers developers to pack, ship and run their applications quickly and reliably. Control how modules connect to the Docker API by passing the following parameters: Control how the modules connect to the Docker API by setting the following variables in the environment of the host This allows you to write tasks and execute them inside environments of your choice. # Can also use [ansible] if wanting it to be an ad-hoc command version Where does the configuration file live and what can I configure in it? Run the following ansible-playbook command against your playbook (playbook.yml) to deploy Docker containers to your managed hosts. Working with Command Output in Network Modules, Installing multiple roles from multiple files, Using Python 3 on the managed machines with commands and playbooks, What to do if an incompatibility is found, Integrating Testing With Ansible Playbooks, Sanity Tests required-and-default-attributes. Ansible Vault allows you to encrypt playbooks and variables. It also provides a robust set of features and built-in modules which facilitate writing automation scripts. You will need to have >= 1.7.0 installed for Python 2.7 or Python 3. For a connection test, check Step 3 of How to Install and Configure Ansible on Ubuntu 20.04. How do I handle different machines needing different user accounts or ports to log in with? Ansible is a powerful tool for automating software and hardware configurations. Provide the password you used to encrypt the file when prompted, and youll see the decrypted version of the file, as shown below. And list your Docker containers on the remote server: This means the containers defined in the playbook were created successfully. The $ANSIBLE_VAULT;1.1;AES256 string at the header of the playbook file indicates that the file is encrypted with Ansible Vault using the AES256 cipher. If youd like to follow along, be sure you have the following. You will get output similar to this: Note: For more information on how to run Ansible playbooks, check our Ansible Cheat Sheet Guide. RUN echo host * >> ~/.ssh/config &&\ | 2022 DigitalOcean, LLC. Dev/Ops passionate about open source, PHP, and Linux. Tells Ansible which inventory to use, in this example it is looking for a file call inventory_file_name. The \ means the command continues on the next line. Want to support the writer? # Sets environment variables How do I see all the inventory vars defined for my host? How do I see a list of all of the ansible_ variables? by py-setuptools \ We use cookies on our websites to deliver our online services. By default the script will look for %t min read Related:How to Leverage Ansible Variables in Roles and Playbooks. Below, you can see four containers running each host you specified in the playbook (playbook.yml) and their container names. Related:How to Install Ubuntu 20.04 [Step-by-Step]. How do I copy files recursively onto a target host? Copyright 2018 Red Hat, Inc. # Connect to the Docker API on localhost port 4243 and format the JSON output, # Any container's ssh port exposed on 0.0.0.0 will be mapped to, # another IP address (where Ansible will attempt to connect via SSH). As you can see, the playbook file is encrypted and can only be read by someone who has the password to decrypt the file. You will need a vault password that you used to encrypt your secret. Hate ads? RUN mkdir ~/.ssh, > Creating Ansible directory and the /.ssh directory, # Over rides SSH Hosts Checking Notice the code is divided into two sections: Now that you have a playbook, you might want to share it with other people for collaboration. Modules in Ansible are shortcuts to execute operations that you would otherwise have to run as raw bash commands. Ansible offers a simple architecture that doesnt require special software to be installed on nodes. In this case, the path points to the directory and Dockerfile that were copied to the build host. The amount of time in seconds to wait on an API response. This program wont install with Ansible. Two or more machines (Ansible hosts) These hosts can be virtual machines, physical servers, or Rasberry Pis. Why can I run a command locally that does not work under Ansible? Running this playbook will perform the following actions on your Ansible hosts: Once the playbook has finished running, you will have a number of containers created based on the options you defined within your configuration variables. alpine:latest would change it to the latest release, or another operating system could be used (which may increase the image size). Youll create an inventory file to declare the hosts that Ansible can manage. tar && \ This number is used here to name your containers. Create a new file called playbook.yml in your current working directory using your preferred text editor. This article walked you through the use of the Ansible Docker image module, which provides a way to manage container images on remote hosts. ENV PYTHONPATH /ansible/lib, # Sets entry point (same as running ansible-playbook) An automation tool by Red Hat,Ansible, aims to simplify tasks like configuration management, application deployment, and intra-service orchestration. Use a CA certificate when performing server verification by providing the path to a CA certificate file. You learned how to build, save, and load an image through simple Ansible playbooks. How to secure your sensitive information? Related:How to Build (And Actually Understand) a Solid Ansible Playbook. Now, copy/paste the code block from a GitHub repository into the newly created playbook.yml file. At the same time, the file contains any variables or settings specific to those hosts. This playbook will install the Docker package and its dependencies on the dev server and will create containers to set up your Drupal application along with the MySQL database. Parameters. # Downloads the Ansible tar (curl) and saves it (-o) docker01 and docker02 - These hosts are used to run containers. In order to execute the automated setup provided by the playbook in this guide, youll need: Before proceeding, you first need to make sure your Ansible control node is able to connect and execute commands on your Ansible host(s). Connect using TLS without verifying the authenticity of the Docker host server. docker) with an extension of .yml. This guide explains how to use Ansible to automate the steps contained in our guide on How To Install and Use Docker on Ubuntu 20.04. 3 Minute Read. How to limit container privilege with socket activation, How to manage pods in Podman with the REST API, How to encrypt sensitive data in playbooks with Ansible Vault, Ansible Automation Platform trial subscription, A system administrator's guide to IT automation, Migrating to Ansible Automation Platform 2, Ansible Essentials: Simplicity in Automation Technical Overview. Once youre satisfied with your playbook, you can exit your text editor and save. Maybe you don't want to upload your image for security reasons, or maybe your cluster is just sufficiently small (e.g., in your home lab) that you don't want to deal with a repository (whether external or self-hosted). As a result, the human error when manually configuring servers is eliminated, and the application environment can be replicated. This allows installation of the latest version of Docker, along with using pip to install the module for Python. Using Ansible provides a simple, repeatable, defined state of your containers that can be easily tracked for any potential vulnerabilities, along with tracking actions like who deployed what container, with what code, where, and when. with the actual IP addresses of your managed hosts. running Ansible: The inventory script generates dynamic inventory by making API requests to one or more Docker APIs. Next, run the cat command to view the playbook file. Why not write on a platform with an existing audience and share your knowledge with the world? This was a simple playbook to build an image and create some Docker containers. Look no further than Ansible. echo StrictHostKeyChecking no >> ~/.ssh/config. docker_container allows you to specify the specifics of the containers you create, along with the command you want to pass them. The image that I use in this article is very simple: it just launches a netcat listener on port 8080 and waits for client connections, as you can see from the Dockerfile: A simple Ansible playbook can then be used to build a container image based on this Dockerfile: This playbook creates a build directory on the "build" server, copies the Dockerfile to this directory, and then builds the container using the docker_image Ansible module. Containers work by isolating the software from its environment and ensure standardization by separating application dependencies from infrastructure. Since this was the last task in the playbook, it also confirms that the playbook was fully executed on this server. Most playbooks are configured to be executed on every server in your inventory by default, but youll specify your server this time. This will ensure all packages are not only present, but on the latest version, and done after an update with apt is called. Add your first tasks of installing aptitude, a tool for interfacing with the Linux package manager, and installing the required system packages. curl -fsSL https://releases.ansible.com/ansible/ansible-2.9.3.tar.gz -o ansible.tar.gz If you have a use case for avoiding the storage of your container images in a repository, then you're in luck! vars allows you to store data in variables. Below, you can see two groups (webservers and all), and each group contains the appropriate hosts you declared in the hosts file. While out of scope for this article, you can gain some efficiencies with this thin wrapper around rsync. # apline:latest could also be used Why am I getting an error SSL CERTIFICATE_VERIFY_FAILED? Get many of our tutorials packaged as an ATA Guidebook. The Ansible Docker image module also includes support to export an image to a tar file: This playbook first archives the image using the docker_image module and then fetches the file from the remote server and places it into the local directory. become states whether all commands will be done with escalated root privileges. This tutorial will be a hands-on demonstration. ], Anthony Critelli is a Linux systems engineer with interests in automation, containerization, tracing, and performance. Once the playbook has successfully run, the container image can be seen when listing out the available images on any of the Docker hosts: You can then launch a container on one of the hosts and see that it works. You can add or remove packages to your liking. The content published on this site are community contributions and are for informational purpose only AND ARE NOT, AND ARE NOT INTENDED TO BE, RED HAT DOCUMENTATION, SUPPORT, OR ADVICE. By default, these images come from the official Docker Hub. with_sequence is the Ansible way of creating a loop, and in this case it will loop the creation of your containers according to the count you specified. Run the following ansible-vault command to encrypt your playbook file (playbook.yml). options. All rights reserved. This Ansible playbook provides an alternative to manually running through the procedure outlined in our guide on How To Install and Use Docker on Ubuntu 20.04. Sign up for Infrastructure as a Newsletter. Docker is an executable package built on a highly optimized platform for running software on containers. Using socket activation with the --network=none option limits an intruder's ability to use a compromised container as a starting point for attacks on other devices. In./inventory/dev/host.ymlinventory file, we have our host defined and some variables specific to the dev environment since you can have different values for these variables for other environments. The opinions expressed on this website are those of each author, not of the author's employer or of Red Hat. Under./inventory, we have inventory files for all environments like dev, stage, prod, etc. maps a directory into the container (in above example current working directory of host becomes /ansible/playbooks of container). Which notation should I use? Learn how to configure, inspect, and start pods in Podman with the REST API. Ansible will ensure these packages are always installed on your server: Here, youre using the apt Ansible builtin module to direct Ansible to install your packages. ENV ANSIBLE_HOST_KEY_CHECKING False