## dev-lxc dev-lxc builds and manages clusters of LXC containers and includes the ability to install and configure Chef products. Cluster management includes the ability to manage snapshots of the containers which makes dev-lxc well suited as a tool for support related work, customized cluster builds for demo purposes, as well as general experimentation and exploration. ### Features 1. LXC 2.0 Containers - Resource efficient servers with fast start/stop times and standard init 2. Btrfs - Efficient, persistent storage backend provides fast, lightweight container snapshots 3. Dnsmasq - DHCP networking and DNS resolution 4. Base Containers - Containers that are built to resemble a traditional server 5. ruby-lxc - Ruby bindings for liblxc 6. YAML - Simple, flexible definition of clusters 7. Build process closely follows online installation documentation 8. Snapshots - Snapshots are created during the cluster's build process which makes rebuilding a cluster very fast. 9. mixlib-install library - Automatically manages a cache of Chef products Its containers, standard init, networking and build process are designed to be similar to what you would build if you follow the online installation documentation so the end result is a cluster that is relatively similar to a more traditionally built cluster. The Btrfs backed snapshots provide a quick clean slate which is helpful especially for experimenting and troubleshooting. Or it can be used to build a customized cluster for demo purposes and be able to bring it up quickly and reliably. If you aren't familiar with using containers please read this introduction. [LXC 1.0 Introduction](https://www.stgraber.org/2013/12/20/lxc-1-0-blog-post-series/) ### Requirements * Please follow the [Prerequisite Instructions](docs/prerequisites.md) When you are done with the prerequisites you should be able to log into the dev-lxc-platform VM and start using it. You must login to the root user to use the dev-lxc command. ``` cd dev-lxc-platform vagrant ssh sudo -i ``` ### Update dev-lxc gem Run the following command if you ever need to upgrade the dev-lxc gem inside the dev-lxc-platform VM. ``` chef gem update dev-lxc ``` ### Display Help ``` dev-lxc help dev-lxc help ``` ### dev-lxc Alias and Subcommands The dev-lxc command has a `dl` alias for ease of use. You only have to type enough of a `dev-lxc` subcommand to make it unique. For example, the following commands are equivalent: ``` dev-lxc status dl st ``` ``` dev-lxc snapshot dl sn ``` ### Demo: Build Chef Automate Cluster Log into the dev-lxc-platform VM's root user. ``` cd dev-lxc-platform vagrant up # if the VM is not already running vagrant ssh sudo -i ``` When you are logged in as the root user you should automatically enter a [byobu session](http://byobu.co/). Byobu makes it easy to manage multiple terminal windows and panes. You can press `fn-F1` to get help which includes a [list of keybindings](http://manpages.ubuntu.com/manpages/wily/en/man1/byobu.1.html#contenttoc8). Some of the keys that will be most useful to you are: * `option-Up`, `option-Down` to switch between Byobu sessions * `option-Left`, `option-Right` to switch between windows in a session * `shift-Left`, `shift-Right`, `shift-Up`, `shift-Down` to switch between panes in a window #### Create Base Container The [base container](docs/base_containers.md) used for the cluster's containers must be created first. Let's use Ubuntu 14.04 for the base container. ``` dl create b-ubuntu-1404 ``` #### Create Config File Create the [dev-lxc.yml config file](docs/configuration.md) for the cluster. First, create an arbitrary directory to hold the dev-lxc.yml file. ``` mkdir -p /root/work/clusters/automate ``` Then use the `init` subcommand to generate a sample configuration using the available options. Run `dl help init` to see what options are available. The following command configures a standalone Chef Server, a Chef Automate server and a build node. ``` dl init --chef --automate --build-nodes -f /root/work/clusters/automate/dev-lxc.yml ``` We can easily append additional configurations to this file. For example, the following command appends an infrastructure node. ``` dl init --nodes -a -f /root/work/clusters/automate/dev-lxc.yml ``` Edit the dev-lxc.yml file: * Delete the `reporting` product from the Chef Server config since we will be using Chef Automate's Visibility. * Set the Automate server's `license_path` value to the location of your license file. * (Optionally) Modify the server names to make them [unique from other clusters](docs/manage_multiple_clusters.md) you may define. #### cluster-view Run the `cluster-view` command to create a Byobu session specifically for this cluster. The session's first window is named "cluster". The left pane is useful for running dev-lxc commands. The right pane updates every 0.5 seconds with the cluster's status provided by `dev-lxc status`. The session's second window is named "shell". It opens in the same directory as the cluster's `dev-lxc.yml` file and is useful for attaching to a server to perform system administration tasks. See the [usage docs](docs/usage.md) for more information about how to close/kill Byobu sessions. ``` cluster-view /root/work/clusters/automate ``` #### Specifying a Subset of Servers Many dev-lxc subcommands can act on a subset of the cluster's servers by specifying a regular expression that matches the desired server names. For example, the following command will show the status of the build node and the infrastructure node. ``` dl status node ``` #### Build the Cluster dev-lxc knows to build the servers in an appropriate order. It downloads the product packages to a cache location and installs the packages in each server. It configures each product and creates necessary things such as Chef organizations and users as needed. ``` dl up ``` Note: You also have the option of running the `prepare-product-cache` subcommand which downloads required product packages to the cache. This can be helpful when you don't want to start building the cluster yet but you want the package cache ready when you build the cluster later. #### Use the Servers At this point all of the cluster's servers should be running. If you setup the workstation's networking correctly as described in the prerequisites you should be able to ping any server from your workstation using it's FQDN. You can also browse to any server that has a web interface. Since the cluster has a Chef Server you can use the `chef-repo` subcommand to create a chef-repo directory in the VM that contains a knife.rb and all of the keys for the users and org validator clients that are defined in dev-lxc.yml. This makes it very easy to use tools such as knife or berkshelf. ``` dl chef cd chef-repo knife client list cd .. ``` Since the cluster has a Chef Automate server you can use the `print-automate-credentials` subcommand to see what the login credentials. ``` dl print ``` You can use the `attach` subcommand to login to the root user of a server. For example, the following command should attach to the Chef Server. ``` dl at chef ``` Since the cluster has a Chef Server and an infrastructure node dev-lxc made sure it configured the node's chef-client for the Chef Server so it is easy to converge the node. #### Manage the Cluster The right pane of the "cluster" window should show `dev-lxc status` output. This shows the status of each server including any existing snapshots. It is recommended that you stop the servers before restoring or creating snapshots. ``` dl halt ``` You can restore the most recent snapshot of all the servers. ``` dl sn -r ``` You could also restore a specific snapshot by name if you desire. For example, you could restore the Chef Automate server to the state right after its package was installed but before it was configured. ``` dl sn automate -r snap0 ``` You can create snapshots with or without a comment. ``` dl sn -c 'Demo snapshot' ``` You can destroy snapshots. ``` dl sn -d snap2 ``` And finally you can destroy the servers and there snapshots. ``` dl d ``` ## Contributing 1. Fork it 2. Create your feature branch (`git checkout -b my-new-feature`) 3. Commit your changes (`git commit -am 'Add some feature'`) 4. Push to the branch (`git push origin my-new-feature`) 5. Create new Pull Request