Easy building and installing of Erlang/OTP instances
Kerl aims to be shell agnostic and its only dependencies, excluding what's required to actually build Erlang/OTP, are curl and git.
Unless explicitly disabled, agner is installed automatically in the sandboxes for supported Erlang/OTP versions.
All is done so that, once a specific release has been built, creating a new installation is as fast as possible.
You can download the script directly from github:
$ curl -O https://github.com/evax/kerl/raw/master/kerl
Then ensure it is executable
$ chmod a+x kerl
and drop it in your $PATH
Optionally download and install kerl's bash_completion file from https://github.com/evax/kerl/raw/master/bash_completion/kerl
Kerl keeps tracks of the releases it downloaded, built and installed, allowing easy installations to new destinations (without complete rebuilding) and easy switches between Erlang/OTP installations.
List the available releases (kerl ignores releases < 10):
$ kerl list releases
Getting the available releases from erlang.org...
R10B-0 R10B-2 R10B-3 R10B-4 R10B-5 R10B-6 R10B-7 R10B-8 R10B-9 R11B-0 R11B-1
R11B-2 R11B-3 R11B-4 R11B-5 R12B-0 R12B-1 R12B-2 R12B-3 R12B-4 R12B-5 R13A
R13B R13B01 R13B02 R13B03 R13B04 R14A R14B R14B01 R14B02
Run "./kerl update releases" to update this list from erlang.org
Pick your choice and build it:
$ kerl build R14B02 r14b02
Downloading otp_src_R14B02.tar.gz to /home/evax/.kerl/archives
(curl progresses...)
Verifying archive checksum...
(curl progresses...)
Checksum verified (229fb8f193b09ac04a57a9d7794349b7)
Extracting source code
Building Erlang/OTP R14B02 (r14b02), please wait...
Erlang/OTP R14B02 has been successfully built
Fetching and building agner...
Agner has been successfully built
Note that named builds allow you to have different builds for the same Erlang/OTP release with different configure options:
$ KERL_CONFIGURE_OPTIONS=--enable-hipe kerl build R14B02 r14b02_hipe
Verifying archive checksum...
Checksum verified (229fb8f193b09ac04a57a9d7794349b7)
Extracting source code
Building Erlang/OTP R14B02 (r14b02_hipe), please wait...
Erlang/OTP R14B02 (r14b02_hipe) has been successfully built
Fetching and building agner...
Agner has been successfully built
(Note that kerl uses the otp_build script internally, and './otp_build configure' disables HiPE on linux)
You can verify your build has been registered:
$ kerl list builds
R14B02,r14b02
R14B02,r14b02_hipe
Now install a build to some location (optionally you can disable agner support by adding KERL_DISABLE_AGNER=yes to your $HOME/.kerlrc file, or on the contrary define a list of additional packages to install using the KERL_AGNER_AUTOINSTALL directive in the same file or on the command line):
$ kerl install r14b02 /path/to/install/dir/
Installing Erlang/OTP R14B02 (r14b02) in /path/to/install/dir...
Installing agner in /path/to/install/dir...
You can activate this installation running the following command:
. /path/to/install/dir/activate
Later on, you can leave the installation typing:
kerl_deactivate
Here again you can check the installation's been registered:
$ kerl list installations
r14b02 /path/to/install/dir
And at last activate it:
$ . /path/to/install/dir/activate
Activation will backup your $PATH, prepend it with the installation's bin/ directory and do the right thing with AGNER_* vars to constrain agner operations to the sandbox. Thus it's only valid for the current shell session, and until you activate another installation or call kerl_deactivate.
You're now ready to work with your r14b02 installation:
$ erl -version
Erlang (SMP,ASYNC_THREADS,HIPE) (BEAM) emulator version 5.8.3
$ agner version
0.4.16
You can use agner to install packages in your activated installation, they'll be directly available:
$ agner install cowboy
(...)
Installed to:
/path/to/install/dir/lib/cowboy-@master
$ erl
(...)
Eshell V5.8.3 (abort with ^G)
1> application:start(cowboy).
ok
Note that you can also define a list of packages to be autoinstalled on agner enabled installations using the KERL_AGNER_AUTOINSTALL entry in you $HOME/.kerlrc file
When your done just type: $ kerl_deactivate
Anytime you can check which installation, if any, is currently active with:
$ kerl active
No Erlang/OTP kerl installation is currently active
You can get an overview of the current kerl state with:
$ kerl status
Available builds:
R14B02,r14b02
R14B02,r14b02_hipe
----------
Available installations:
r14b02 /path/to/install/dir
----------
Currently active installation:
The current active installation is:
/path/to/install/dir
You can delete builds and installations with the following commands:
$ kerl delete build r14b02
The r14b02 build has been deleted
$ kerl delete installation /path/to/install/dir
The installation in /path/to/install/dir has been deleted
You can update the agner version associated with a specific build (this will only affect installations made after that):
$ kerl update agner r14b02
Updating agner for build r14b02...
agner has been updated successfully
As an experimental feature, you can build Erlang directly from a git repository with a command of the form "kerl build git <git_url> <git_version> <build_name>" where <git_version> can be either a branch, a tag or a commit id as it will be passed to "git checkout":
$ kerl build git https://github.com/erlang/otp.git dev r14b02_dev
Checking Erlang/OTP git repositoy from https://github.com/erlang/otp.git...
Building Erlang/OTP r14b02_dev from git, please wait...
Erlang/OTP r14b02_dev from git has been successfully built
Fetching and building agner...
Agner has been successfully built
You can tune kerl using the .kerlrc file in your $HOME directory.
You can set the following variables:
- KERL_DOWNLOAD_DIR where to put downloaded files, defaults to $HOME/.kerl/archives
- KERL_BUILD_DIR where to hold the builds, defaults to $HOME/.kerl/builds
- KERL_CONFIGURE_OPTIONS options to pass to Erlang's ./configure script, e.g. --without-termcap
- KERL_DISABLE_AGNER if non-empty will disable agner support
- KERL_AGNER_AUTOINSTALL a list of packages to pre-install
- KERL_SASL_STARTUP use SASL system startup instead of minimal
- KERL_USE_AUTOCONF use autoconf in the builds process
Here are the abstractions kerl is handling:
-
releases: Erlang/OTP releases from erlang.org
-
builds: the result of configuring and compiling releases or git repositories
-
installations: the result of deploying builds to filesystem locations (also referred to as "sandboxes")
Create a named build either from an official Erlang/OTP release or from a git repository
kerl build <release_code> <build_name>
kerl build git <git_url> <git_version> <build_name>
$ kerl build R14B02 r14b02
$ kerl build git https://github.com/erlang/otp dev r14b02_dev
You can disable agner support by setting KERL_DISABLE_AGNER=yes in your $HOME/.kerlrc file
You can specify the configure options to use when building Erlang/OTP with the KERL_CONFIGURE_OPTIONS variable, either in your $HOME/.kerlrc file or prepending it to the command line.
$ KERL_CONFIGURE_OPTIONS=--enable-hipe kerl build R14B02 r14b02_hipe
You can enable the use of autoconf in the build process setting KERL_USE_AUTOCONF=yes in your $HOME/.kerlrc file
Note: autoconf is always enabled for git builds
Install a named build to the specified filesystem location
kerl install <build_name> [path]
If path is ommited the current working directory will be used
$ kerl install r14b02 /srv/otp/r14b02
You can auto-install agner packages listing them in the KERL_AGNER_AUTOINSTALL variable in your $HOME/.kerlrc file or on the command line, e.g. KERL_AGNER_AUTOINSTALL="erlzmq cowboy"
You can have SASL started automatically setting KERL_SASL_STARTUP=yes in your $HOME/.kerlrc file or prepending it to the command line
Update the releases list or the agner version of the specified named build
kerl update releases
kerl update agner <build_name>
List the releases, builds or installations available
kerl list <releases|builds|installations>
Delete the specified build or installation
kerl delete build <build_name>
kerl delete installation <path>
$ kerl delete build r14b02
The r14b02 build has been deleted
$ kerl delete installation /srv/otp/r14b02
The installation in /srv/otp/r14b02 has been deleted
Print the path of the currently active installation, if any
$ kerl active
The current active installation is:
/srv/otp/r14b02
Print the available builds and installations as well as the currently active installation
$ kerl status
Available builds:
R14B02,r14b02
git,r14b02_dev
----------
Available installations:
r14b02 /srv/otp/r14b02
r14b02 /srv/otp/r14b02_dev
----------
No Erlang/OTP kerl installation is currently active