kerl

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 explicitely disabled, agner is installed automatically in the sandboxes for supported Erlang/OTP versions.

All done so that, once a specific release has been built, creating a new installation is as fast as possible.

Downloading

You can download the script directly from github:

$ curl -O https://github.com/evax/kerl/raw/master/kerl

Then ensure its executable

$ chmod a+x kerl

and drop it in your $PATH

How it works

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.

Usage

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=--disable-hipe kerl build R14B02 r14b02_nohipe
Verifying archive checksum...
Checksum verified (229fb8f193b09ac04a57a9d7794349b7)
Extracting source code
Building Erlang/OTP R14B02 (r14b02_nohipe), please wait...
Erlang/OTP R14B02 (r14b02_nohipe) has been successfully built
Fetching and building agner...
Agner has been successfully built

You can verify your build has been registered:

$ kerl list builds
R14B02,r14b02
R14B02,r14b02_nohipe

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):

$ 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

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_nohipe
----------
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

Tuning

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