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.

All is 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://raw.githubusercontent.com/kerl/kerl/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/kerl/kerl/raw/master/bash_completion/kerl

Optionally download and install kerl's zsh-completion file from https://github.com/kerl/kerl/raw/master/zsh_completion/_kerl

How it works

Kerl keeps tracks of the releases it downloads, builds and installs, allowing easy installations to new destinations (without complete rebuilding) and easy switches between Erlang/OTP installations.

By default, kerl downloads source tarballs from the official Erlang website, but you can tell kerl to download tarballs of Erlang source code from the tags pushed to the official source code by setting KERL_BUILD_BACKEND=git

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

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

(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:

$ kerl install r14b02 /path/to/install/dir/
Installing Erlang/OTP R14B02 (r14b02) 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. 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

When you're done just call the shell function:

$ 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 easily deploy an installation to another host having ssh and rsync access with the following command:

$ kerl deploy anotherhost /path/to/install/dir
Cloning Erlang/OTP r14b02 (/path/to/install/dir) to anotherhost (/path/to/install/dir) ...
On anotherhost, you can activate this installation running the following command:
. /path/to/install/dir/activate
Later on, you can leave the installation typing:
kerl_deactivate

Building from a git source

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 that 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

Tuning

You can tune kerl using the .kerlrc file in your $HOME directory.

You can set the following variables:

• KERL_BUILD_BACKEND which source code download provider to use - (tarball - default) erlang.org or github (git)
• 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_DEFAULT_INSTALL_DIR if set in ~/.kerlrc, install builds to this dir if no path is provided on installs, (recommend $KERL_BASE_DIR/installs)
• KERL_CONFIGURE_OPTIONS options to pass to Erlang's ./configure script, e.g. --without-termcap
• KERL_CONFIGURE_APPLICATIONS if non-empty, subset of applications used in the builds (and subsequent installations) process, e.g. kernel stdlib sasl
• KERL_CONFIGURE_DISABLE_APPLICATIONS if non-empty, subset of applications disabled in the builds (and subsequent installations) process, e.g. odbc
• KERL_SASL_STARTUP use SASL system startup instead of minimal
• KERL_DEPLOY_SSH_OPTIONS if additional options are required, e.g. -qx -o PasswordAuthentication=no
• KERL_DEPLOY_RSYNC_OPTIONS if additional options are required, e.g. --delete
• KERL_ENABLE_PROMPT if set, the prompt will be prefixed with the name of the active build
• KERL_BUILD_DOCS if set, will build documentation from source code repository
• KERL_USE_AUTOCONF use autoconf in the builds process (note: implied by the git build backend)

Options for tarball builds only

These options only work when KERL_BUILD_BACKEND=tarball (the default) and if KERL_BUILD_DOCS is not set. That is, they are strictly for backward compatibility. They will probably be removed in a future release.

• KERL_INSTALL_MANPAGES if non-empty will install manpages into /install/path/man
• KERL_INSTALL_HTMLDOCS if non-empty will install HTML docs into /install/path/html

If you want documentation for git based builds, set KERL_BUILD_DOCS=yes - and if you don't want to download 120MB of docs from erlang.org, also set KERL_BUILD_DOCS=yes

Note on .kerlrc

Since .kerlrc is a dot file for /bin/sh, running shell commands inside the .kerlrc will affect the shell and environment variables for the commands being executed later. For example, the shell export commands in .kerlrc will affect your login shell environment when activating curl. Use with care.

Fish shell support

kerl has basic support for the fish shell.

To activate an installation:

source /path/to/install/dir/activate.fish

Deactivation is the same as in other shells:

kerl_deactivate

Please note: if you've installed a build with an older version of kerl (1.2.0 older) it won't have the activate.fish script.

Glossary

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")

Commands reference

build

kerl build <release_code> <build_name>
kerl build git <git_url> <git_version> <build_name>

Creates a named build either from an official Erlang/OTP release or from a git repository.

$ kerl build R14B02 r14b02
$ kerl build git https://github.com/erlang/otp dev r14b02_dev

Tuning

Configure options

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

Configure applications

If non-empty, you can specify the subset of applications to use when building (and subsequent installing) Erlang/OTP with the KERL_CONFIGURE_APPLICATIONS variable, either in your $HOME/.kerlrc file or prepending it to the command line.

$ KERL_CONFIGURE_APPLICATIONS="kernel stdlib sasl" kerl build R15B01 r15b01_minimal

Configure disable applications

If non-empty, you can specify the subset of applications to disable when building (and subsequent installing) Erlang/OTP with the KERL_CONFIGURE_DISABLE_APPLICATIONS variable, either in your $HOME/.kerlrc file or prepending it to the command line.

$ KERL_CONFIGURE_DISABLE_APPLICATIONS="odbc" kerl build R16B02 r16b02_no_odbc

Enable autoconf

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

Using shell export command in .kerlrc

Configure variables which includes spaces such as those in CFLAGS cannot be passed on with KERL_CONFIGURE_OPTIONS. In such a case you can use shell export command to define the environment variables for ./configure. Note well: this method has a side effect to change your shell execution environment after activating a kerl installation of Erlang/OTP. Here is an example of .kerlrc for building Erlang/OTP for FreeBSD with clang compiler:

# for clang
export CC=clang CXX=clang CFLAGS="-g -O3 -fstack-protector" LDFLAGS="-fstack-protector"
# compilation options
KERL_CONFIGURE_OPTIONS="--disable-native-libs --enable-vm-probes --with-dynamic-trace=dtrace --with-ssl=/usr/local --with-javac --enable-hipe --enable-kernel-poll --with-wx-config=/usr/local/bin/wxgtk2u-2.8-config --without-odbc --enable-threads --enable-sctp --enable-smp-support"

Building documentation

Prior to kerl 1.0, kerl always downloaded prepared documentation from erlang.org. Now if KERL_BUILD_DOCS=yes is set, kerl will build the man pages and HTML documentation from the source repository in which is working.

Note: This variable takes precedent over the other documentation parameters.

install

kerl install <build_name> [path]

Installs a named build to the specified filesystem location.

$ kerl install r14b02 /srv/otp/r14b02

If path is omitted the current working directory will be used. However, if KERL_DEFAULT_INSTALL_DIR is defined in ~/.kerlrc, KERL_DEFAULT_INSTALL_DIR/<build-name> will be used instead.

Install location restrictions

WARNING: kerl assumes the given installation directory is for its sole use. If you later delete it with the kerl delete command, the whole directory will be deleted, along with anything you may have added to it!

So please only install kerl in an empty (or non-existant) directory.

If you attempt to install kerl in $HOME or .erlang or $KERL_BASE_DIR, then kerl will give you an error and refuse to proceed. If you try to install kerl in a directory that exists and is not empty, kerl will give you an error.

Tuning

SASL startup

You can have SASL started automatically setting KERL_SASL_STARTUP=yes in your $HOME/.kerlrc file or prepending it to the command line.

Manpages installation

You can have manpages installed automatically setting KERL_INSTALL_MANPAGES=yes in your $HOME/.kerlrc file or prepending it to the command line.

Note: for git-based builds, you want to set KERL_BUILD_DOCS=yes

HTML docs installation

You can have HTML docs installed automatically setting KERL_INSTALL_HTMLDOCS=yes in your $HOME/.kerlrc file or prepending it to the command line.

Note: for git-based builds, you want to set KERL_BUILD_DOCS=yes

Documentation installation

Man pages will be installed to [path]/man and HTML docs will be installed in [path]/html. The kerl activate script manipulates the MANPATH of the current shell such that man 3 gen_server or erl -man gen_server should work perfectly.

(Do not fret - kerl_deactivate restores your shell's MANPATH to whatever its original value was.)

deploy

kerl deploy <[user@]host> [directory] [remote_directory]

Deploys the specified installation to the given host and location.

$ kerl deploy anotherhost /path/to/install/dir

If remote_directory is omitted the specified directory will be used.

If directory and remote_directory is omitted the current working directory will be used.

NOTE: kerl assumes the specified host is accessible via ssh and rsync.

Tuning

Additional SSH options

You can have additional options given to ssh by setting them in the KERL_DEPLOY_SSH_OPTIONS variable in your $HOME/.kerlrc file or on the command line, e.g. KERL_DEPLOY_SSH_OPTIONS='-qx -o PasswordAuthentication=no'.

Additional RSYNC options

You can have additional options given to rsync by setting them in the KERL_DEPLOY_RSYNC_OPTIONS variable in your $HOME/.kerlrc file or on the command line, e.g. KERL_DEPLOY_RSYNC_OPTIONS='--delete'.

update

kerl update releases

If KERL_BUILD_BACKEND=tarball this command fetches the up-to-date list of OTP releases from erlang.org.

If it is set to KERL_BUILD_BACKEND=git this command fetches an up-to-date list of OTP tags from the official OTP github repository.

list

kerl list <releases|builds|installations>

Lists the releases, builds or installations available.

delete

kerl delete build <build_name>
kerl delete installation <path>

Deletes the specified build or installation.

$ 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

active

kerl active

Prints the path of the currently active installation, if any.

$ kerl active
The current active installation is:
/srv/otp/r14b02

status

kerl status

Prints 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

Changelog

1 July 2016 - 1.3.0

• basic fish shell support (#91)

28 June 2016 - 1.2.0

• Make curl output more robust if using a .curlrc (#137)
• Apply patches to build older Erlangs (#138)
• Add a command to output a version string (#140)
• Do not assume success for metadata file writes (#142)
• Fix a grammar problem (#145)

20 May 2016 - 1.1.1

• Remove valid directory check when doing a remote deployment.
• Various get_otp_version() regex cleanup/fixes

14 May 2016 - 1.1.0

• Remove support for Mac OS X Lion. Stop setting CFLAGS for better compiler optimizations. (#132)

14 May 2016 - 1.0.1

• Be much more careful about installing into and removing directories. (#127)
• Make OTP_GITHUB_URL and KERL_BUILD_BACKEND controllable from .kerlrc (#130)

2 May 2016 - 1.0

• Support builds from git tags (#122)
• Support documentation builds/installs from source code (#126)