[![Build Status](https://travis-ci.org/stackbuilders/hapistrano.svg?branch=master)](https://travis-ci.org/stackbuilders/hapistrano) [![Hackage version](https://img.shields.io/hackage/v/hapistrano.svg)](http://hackage.haskell.org/package/hapistrano) # Hapistrano Hapistrano is a deployment library for Haskell applications similar to Ruby's [Capistrano](http://capistranorb.com/). ## Purpose We created Hapistrano because: * Deploys should be simple, but as close to atomic as possible (eg, they shouldn't require much application downtime). * Rollback should be trivial to achieve to bring the application back to the last-deployed state. * Deploys shouldn't fail because of dependency problems. ## How it Works Hapistrano (like Capistrano for Ruby) deploys applications to a new directory marked with a timestamp on the remote host. It creates this new directory quickly by placing a git repository for caching purposes on the remote server. When the build process completes, it switches a symlink to the `current` release directory, and optionally restarts the web server. By default, Hapistrano keeps the last five releases on the target host filesystem and deletes previous releases to avoid filling up the disk. ## Usage Hapistrano 0.3.0.0 looks for a configuration file called `hap.yaml` that typically looks like this: ```yaml deploy_path: '/var/projects/my-project' host: myserver.com port: 2222 repo: 'https://github.com/stackbuilders/hapistrano.git' revision: origin/master build_script: - stack setup - stack build restart_command: systemd restart my-app-service ``` The following parameters are required: * `deploy_path` — the root of the deploy target on the remote host. * `repo` — the origin repository. * `revision` — the SHA1 or branch to deploy. If a branch, you will need to specify it as `origin/branch_name` due to the way that the cache repo is configured. The following parameters are *optional*: * `host` — the target host, if missing, `localhost` will be assumed (which is useful for testing and playing with `hap` locally). * `port` — SSH port number to use. If missing, 22 will be used. * `build_script` — instructions how to build the application in the form of shell commands. * `restart_command` — if you need to restart a remote web server after a successful rollback, specify the command that you use in this variable. It will be run after both deploy and rollback. * `vc_action` - Controls if version control related activity should take place. It defaults to true. When you don't want activity like cloning, fetching etc. to take place, set this to `false`. * `linux` - Specify, whether or not, the target system where Hapistrano will deploy to is a GNU/Linux or other UNIX (g.e. BSD, Mac). This is set to `true` by default so unless the target system is not GNU/Linux, this should not be necessary. The platform where Hapistrano is running won't affect the available options for commands (g.e. A Mac deploying to a Ubuntu machine, doesn't need this flag) * `run_locally:`- Instructions to run locally on your machine in the form of shell commands. Example: ``` run_locally: - pwd - bash deploy.sh ``` Note how we are even able to execute a bash script named `deploy.sh` above. Be sure to use `set -e` in your bash script to avoid headaches. Hapistrano will stop the execution on non zero exit codes. Without the usage of `set -e`, there is a possiblity that your bash script may return a zero exit code even if your intermediate command resulted in an error. After creating a configuration file as above, deploying is as simple as: ```bash $ hap deploy ``` Rollback is also trivial: ```bash $ hap rollback # to rollback to previous successful deploy $ hap rollback -n 2 # go two deploys back in time, etc. ``` ## What to do when compiling on server is not viable Sometimes the target machine (server) is not capable of compiling your application because e.g. it has not enough memory and GHC exhausts it all. You can copy pre-compiled files from local machine or CI server using `copy_files` and `copy_dirs` parameters: ```haskell copy_files: - src: '/home/stackbuilders/my-file.txt' dest: 'my-file.txt' copy_dirs: - src: .stack-work dest: .stack-work ``` `src` maybe absolute or relative, it's path to file or directory on local machine, `dest` may only be relative (it's expanded relatively to cloned repo) and specifies where to put the files/directories on target machine. Directories and files with clashing names will be overwritten. Directories are copied recursively. ## Deploying to multiple machines concurrently Beginning with Hapistrano 0.3.1.0 it's possible to deploy to several machines concurrently. The only things you need to do is to adjust your configuration file and use `targets` parameter instead of `host` and `port`, like this: ```haskell targets: - host: myserver-a.com port: 2222 - host: myserver-b.com # the rest is the same… ``` A few things to note here: * `host` item is required for every target, but `port` may be omitted and then it defaults to `22`. * The deployment will run concurrently and finish when interactions with all targets have finished either successfully or not. If at least one interaction was unsuccessful, the `hap` tool will exit with non-zero exit code. * The log is printed in such a way that messages from several machines get intermixed, but it's guaranteed that they won't overlap (printing itself is sequential) and the headers will tell you exactly which machine was executing which command. If you don't specify `host` and `targets`, `hap` will assume `localhost` as usually, which is mainly useful for testing. ## License MIT, see [the LICENSE file](LICENSE). ## Contributing Pull requests for modifications to this program are welcome. Fork and open a PR. Feel free to [email me](mailto:justin@stackbuilders.com) if you have questions about what may be accepted before working on a PR. If you're looking for a place to start, you may want to check the [open issue](https://github.com/stackbuilders/hapistrano/issues).