cf-deploy v4 released

After five years after the release of cf-deploy v3, I have just released cf-deploy v4. This version of cf-deploy fixes a number of shortcomings that made their way up to this point and that I wasn’t able to see until recently. It is now more flexible and easier to configure than it ever was. In particular, the documentation is way more comprehensive, covering installation, configuration and usage. The documentation also covers some of the internals, that will allow the hardcore user to fine tune the tool to better suit their needs.

You will find cf-deploy on github, as always. Enjoy!

A bit of history

cf-deploy was born when I worked in Opera Software, where we had several projects that used CFEngine for configuration management and all projects leveraged the same library of CFEngine bundles developed in house. We needed a decent way to deploy our CFEngine policies on a fleet of policy hubs scattered across several locations on the planet. we had production, preproduction, staging and test hubs.

In the beginning, we solved the problem through a makefile, which worked but was kind of inconvenient to use in many of the daily operations. Thus we decided to create a front-end to that makefile, so that we didn’t have to remember all those awkward make command lines: we wrote that front-end in bash and we called it cf-deploy. This worked for a while, but as the number of projects, environments and locations grew, managing the configurations for cf-deploy also started to become awkward, so we re-engineered the tool in Perl and around only two configuration files. That worked much better, and the tool was now flexible enough that it could be used to deploy more or less anything, as long as it fitted the case (a set of project-specific files merged with common libraries and deployed somewhere).

Why a new version

The previous releases of cf-deploy however carried with them the legacy of the environment they came from. For example, there was a number of settings and assumptions that made sense in the environment where the tool was born, but out of that environment they made the tool difficult to configure, or even unusable. Unfortunately, I didn’t notice how deep those assumption went and how bad they affected the tool, until recently. I decided to use cf-deploy again to manage a personal project and I hit those shortcomings myself, and decided to fix them.

One of the shortcomings was the documentation. I thought that the on-line help provided by the tool itself was enough, but as I rediscovered some features of the tool I had completely forgotten, I realised how bad and how incomplete the documentation was. Now, and for the first time, cf-deploy has a comprehensive documentation, which includes all the information needed to install and configure the tool and how you can tweak it. I don’t know if it’s enough, but I am quite sure it’s a great improvement compared to what we had until v3.

Installation

  1. head to https://github.com/brontolinux/cf-deploy and choose in which way you will clone the repository
  2. clone the repository in a directory
  3. copy or link cf-deploy in a directory in your path
  4. (recommended) copy the Makefile in a separate directory, where you will also place the other configuration files; we’ll call that directory CFDEPLOY_TOOLDIR

Configuration

The configuraton of cf-deploy is composed of:

  1. the projects database file;
  2. the hubs database file;
  3. a set of environment variables defined in your shell

These three configuration components provide cf-deploy with the information about where your project repositories are, where the files shared by all projects are, and where they must be deployed.

Project repositories

cf-deploy assumes that all the projects it manages are in subdirectories of a certain directory that we’ll call CFDEPLOY_GITDIR. As you can tell from the name, cf-deploy was born in an environment where git was the version control system of choice. Don’t be fooled by the name however, you can use any VCS you like, as long as you also update the commands in the Makefile.

The common libraries that will be deployed with all projects are placed in a directory that we’ll call CFDEPLOY_COMMONDIR. It can be placed anywhere you like, inside our outside $CFDEPLOY_GITDIR. We recommend that you keep these files under version control, too.

cf-deploy doesn’t care if the content of $CFDEPLOY_GITDIR is a single repository or if each directory is a separate repository. If you want to manage all of your projects in a single repository, cf-deploy will only assume that each project is placed in a subdirectory; if you prefer to have separate repositories per project, you just need to clone the repositories for those projects in separate subdirectories under $CFDEPLOY_GITDIR.

The (git) repository branch deployed by cf-deploy is, by default, master. You can set a different default branch by setting the variable CFDEPLOY_BRANCH. You can also deploy specific branches by explicitly mentioning it on the command line.

Configuration files

There are three files that govern the behaviour of cf-deploy. The projects database file, the hub database file, and the Makefile that runs the commands needed to deploy a project. The variable CFDEPLOY_TOOLDIR points to the directory where cf-deploy will find its Makefile. $CFDEPLOY_TOOLDIR will also be the default directory where the projects file and the hub file will be searched. If you want to place these two files somewhere else than the default location, and possibly give them a different name, you can do it by setting the variables CFDEPLOY_PROJDBFILE and CFDEPLOY_HUBDBFILE to the respective full paths of these files.

I suggest that you create a separate directory for these three files, and that they are source-controlled. Alternatively, if you wish to use the Makefile as is, you can set $CFDEPLOY_TOOLDIR to the same directory where you cloned the cf-deploy repository, and set $CFDEPLOY_PROJDBFILE and $CFDEPLOY_HUBDBFILE to other locations. This is because the cf-deploy repository carries two sample database files, and changing them locally will make it difficult to pull future updates of cf-deploy — which is maybe why you wanted to use the Makefile from the repository clone in the first place: to make it easy to exploit updates to cf-deploy and its Makefile.

The projects database file (projects.db)

The projects database file is a CSV-like file. Empty lines, or lines containing only whitespace, will be ignored. Lines beginning with a “#”, possibly preceeded by whitespace, are considered comments and will also be ignored. Quotes don’t have any special meaning.

Each line/record in the file has three fields separated by commas. The first field is the name of a project; the second field is the directory under $CFDEPLOY_GITDIR where the project is located; the third field is the type of the project: if the type is remote, then the project will be deployed on a remote machine; if the type is local, the project will be deployed in a local directory.

Examples

A line like:

myproj, my, remote

Will define a project called myproj. The files related to that project will be found in $CFDEPLOY_GITDIR/my and will be deployed to remote destinations defined in the hub database that is described in the next section.

Note: dashes “-” have special meaning to cf-deploy in project names, please don’t use them; you are free to use underscores “_” though.

A line like:

home, Private, local

defines a project called home. The files related to that project will be found in $CFDEPLOY_GITDIR/Private and will be deployed to the local directory defined in the hub database that is described in the next section.

The hub database file (hub.db)

The hub database file is a CSV-like file. Empty lines, or lines containing only whitespace, will be ignored. Lines beginning with a “#”, possibly preceeded by whitespace, are considered comments and will also be ignored. Quotes don’t have any special meaning.

What the hub database does is to connect the projects defined in the projects database with their hubs and where they are located in the case of remote projects. For local projects, the hub database connects projects with the directories where they should be deployed.

Each line/record in the file has four fields separated by commas:

  • the location of the hub: it could be the name of a city, of a datacenter, of an AWS availability zone… or anything that makes sense to you and identifies where this piece of infrastructure is located, physically or logically; this information will be used when you want to do a deployment only in a specific location;
  • the project owning this hub; the project must of course be defined in the projects database;
  • the environment that is served by this hub; names like prodpreprod and staging are special to cf-deploy, as these are the environments that will be deployed by default if nothing else is specified; any other name that you will set for the environment of an hub (e.g.: test) will result in the hub not receiving updates by default, unless you explicitly deploy to that hub or that environment;
  • the fourth field is an identifier for the hub that will receive your project; for remote projects, this will be a hostname or an IP address; for local projects, this will be a directory.

Examples

A set of lines like these:

Oslo,      myproj, prod,    myproj-prod1.example.com
Oslo,      myproj, preprod, myproj-pre1.example.com
Amsterdam, myproj, test,    myproj-test.example.com
Amsterdam, myproj, prod,    myproj-prod2.example.com
Amsterdam, myproj, preprod, myproj-pre2.example.com

defines the hubs for the project myprod. The projects spans two locations: Oslo and Amsterdam. It has one production and one preproduction hub in each location and, in addition, has a test hub in Amsterdam. When deploying the project, only the test hub in Amsterdam will be left out, unless explicitly requested.

This line:

Oslo, home, prod, /etc/cfengine/test

sets for the local project home, located in Oslo, that it will be deployed in the directory /etc/cfengine/test.

Environment varables and defaults

CFDEPLOY_GITDIR

Directory under which the files for each project are located. Default: /var/cfengine/git

CFDEPLOY_TOOLDIR

Directory where the Makefile, the projects database and the hub database are located. Default: $CFDEPLOY_GITDIR/common/tools/deploy

CFDEPLOY_COMMONDIR

Directory where the common libraries, shared with all projects, are located. Default: $CFDEPLOY_GITDIR/common

CFDEPLOY_PROJDBFILE

Full path of the project database file. Default: $CFDEPLOY_TOOLDIR/projects.db

CFDEPLOY_HUBDBFILE

Full path of the hub database file. Default: $CFDEPLOY_TOOLDIR/hub.db

CFDEPLOY_BRANCH

Branch deployed if none is specified. Default: master

CFDEPLOY_MASTERDIR

For remote projects, this will be the directory on hubs in which your project will be deployed. CFDEPLOY_MASTERDIR will be overridden by an environment variable MASTERDIR if it is set!

For local projects, this variable will be ignored because the local directory where projects will be deployed is defined in the hubs database. For local projects, the directory set in the hub database overrides the environment variable MASTERDIR if present!

The default for this variable is /var/cfengine/masterfiles

Sample settings

These are the settings I am currently using in a personal project of mine. All of my projects are kept in repositories under the directory /home/bronto/Lab; the makefile is in /home/bronto/Lab/cf-deploy, while the project and hub database files are in /home/bronto/Lab/CMdata/services/files/cf-deploy.

CFDEPLOY_BRANCH=master
CFDEPLOY_COMMONDIR=/home/bronto/Lab/CMdata
CFDEPLOY_GITDIR=/home/bronto/Lab
CFDEPLOY_HUBDBFILE=/home/bronto/Lab/CMdata/services/files/cf-deploy/hub.db
CFDEPLOY_PROJDBFILE=/home/bronto/Lab/CMdata/services/files/cf-deploy/projects.db
CFDEPLOY_TOOLDIR=/home/bronto/Lab/cf-deploy

Fine tuning cf-deploy

cf-deploy is just a front-end to a Makefile: it gives you commands that are easy to remember and rewrites them into environment variables and make command lines, so that make knows how to do what you requested. You can customise what cf-deploy does by modifying the commands ran by the targets in the makefile or by setting environment variables, or both. E.g., if you want to deploy files in AWS S3 instead of a remote server, you can replace all the rsync commands in the makefile with the appropriate aws s3 commands from the AWS CLI.

Environment variables set by cf-deploy

cf-deploy sets some environment variables before running make to steer the behaviour of make. These variables are, in a way, the API of cf-deploy. Note that if you set any of these variables manually, they will be overridden by cf-deploy.

HUB_LIST

A space-separated list of hubs where the project will be deployed.

PROJECT_NAME

Name of the project to deploy.

PROJECT

Name of the subdirectory where the project is located.

PROJECT_TYPE

Type of the project: remote or local.

BRANCH

Branch to be deployed.

LOCALDIR

Directory under which the files for each project are located. Same value as CFDEPLOY_GITDIR.

COMMONDIR

Directory where the common libraries, shared with all projects, are located. Same value as CFDEPLOY_COMMONDIR.

MASTERDIR

For remote projects, this variable will be set to the same value as CFDEPLOY_MASTERDIR, unless the variable is already set in the environment. If the variable is already set, its value will not be overridden.

For local projects, cf-deploy will set this variable to the directory where the project will be deployed, overriding any value that you may have set otherwise.

SERVER

Used with the diff command of cf-deploy. The command compares the files in the project with those present on the hub $SERVER and shows the differences.

Environment variables used by the Makefile and not set by cf-deploy

There are more variables used in the Makefile that are not set by cf-deploy and will not be overridden by it. You can further refine the behaviour of cf-deploy by setting these variables.

RSYNC_USER

When deploying via rsync, this will be the remote user used when connecting to the remote hub.

RSYNC_PREPARE_OPTS

When deployng via rsync, these are the options that will be used, along with RSYNC_COMMON_OPTS, in the preparation phase, when the project files and the common files are copied in a temporary directory before they are then synchronised to their final destination.

RSYNC_REMOTE_OPTS

Special options that will be used with rsync when synchronising a project to remote hubs, along with RSYNC_COMMON_OPTS.

RSYNC_COMMON_OPTS

rsync options used for all operations, both for remote and local projects.

RSYNC_OPTS

Basic options for rsync. This normally includes RSYNC_PREPARE_OPTSRSYNC_COMMON_OPTS, and possibly something more.

DIFF_OPTS

Options to use when diff-ing files with the cf-deploy diff command.

TMP_BASE

Base directory for the temporary directories, used e.g. when project and common files are merged. Normally, /var/tmp.

TMP_TEMPLATE

Template used with mktemp to build the name for a temporary directory where project and common files are merged.

Using cf-deploy

This section illustrates the cf-deploy command line. Where a make command is issued, it will also show the make command run by cf-deploy.

cf-deploy

Run without arguments, cf-deploy shows the help page.

This is an internal command and doesn’t activate any make target.

cf-deploy PROJECT_NAME

Equivalent to cf-deploy deploy PROJECT_NAME. See below.

cf-deploy deploy PROJECT_NAME [ branch BRANCH ] [ hub SERVER ]

Deploys project PROJECT_NAME. If PROJECT_NAME contains a dash (e.g.: example-spec) the name is split at the dash and the part on the right side (spec in this example) will be matched against the location and the environments to build the list of the hubs where the project will be deployed. E.g. if you run:

cf-deploy myproj-oslo

then your project myproj will be deployed only on the production/preproduction hubs that are located in Oslo.

If you run:

cf-deploy myproj-test

then your project myproj will be deployed on all the hubs in the test environment.

Note that you cannot combine locations and environments in the same command, you’ll have to run separate commands. Note also that you must avoid having locations that carry the same name as an environment as the results may be at the very least confusing, and in the worst case tragic.

If branch is specified, it deploys the branch BRANCH instead of the default branch. If hub is specified, it will deploy only on the hub HUB.

cf-deploy deploy sets environment variables and then runs the following command for remote projects:

make -e -C $CF_DEPLOY_TOOLDIR deploy

and this command for local projects:

make -e -C $CF_DEPLOY_TOOLDIR deploy_local

cf-deploy preview PROJECT_NAME [ branch BRANCH ] [ hub SERVER ]

Same syntax as cf-deploy deploy, but the rsync command will be run in dry run mode, showing which files would be updated if cf-deploy deploy is run but not actually synchronising files.

cf-deploy preview sets environment variables and then runs the following command for remote projects:

make -e -C $CF_DEPLOY_TOOLDIR preview

and this command for local projects:

make -e -C $CF_DEPLOY_TOOLDIR preview_local

cf-deploy diff PROJECT_NAME hub SERVER [ branch BRANCH ]

Copies the project files for PROJECT_NAME from SERVER to a temporary directory, then deploys the project and common files into a second temporary directory, then runs a recursive diff on the two directories, showing you what will be changed if you deploy the project. Finally, cf-deploy cleans up the temporary directories.

If a different branch is not specified explicitly with the branch option, the default branch for the project will be used.

cf-deploy diff sets environment variables and then runs the following command for remote projects:

make -e -C $CF_DEPLOY_TOOLDIR diff

and this command for local projects:

make -e -C $CF_DEPLOY_TOOLDIR diff_local

cf-deploy list projects

This command lists all the configured projects.

This is an internal command and doesn’t activate any make target.

cf-deploy show PROJECT_NAME

This command shows the configured settings for the project PROJECT_NAME.

This is an internal command and doesn’t activate any make target.

cf-deploy list hubs

This command lists all configured hubs for prod, preprod and staging for all projects.

This is an internal command and doesn’t activate any make target.

cf-deploy list all_hubs

This command lists all configured hubs for all projects, skipping none of them.

This is an internal command and doesn’t activate any make target.

Makefile targets not exercised by cf-deploy

The Makefile has a distclean target that can be used to clean up any temporary directory that was left over by cf-deploy, e.g. when the program was interrupted before it could clean up after itself. Provided that you have properly configured cf-deploy, just run:

make -C $CFDEPLOY_TOOLDIR distclean

and make will take care of the leftovers.

References

If, for any reason, you want to know more about the story of cf-deploy and how it was born, you can check a blog post of mine, written in 2014: “Git repository and deployment procedures for CFEngine policies”. You can also take a look at the slides of my presentation at Config Management Camp 2015.

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