Creating a platform¶
Overview¶
If you need a platform that’s not already available in our platforms repository it’s pretty easy to create a new one based on a existing one.
Platforms are Docker images that are used to deploy your application code on tsuru. tsuru provides a base image which platform developers can use to build upon: base-platform. This platform provides a base deployment script, which handles package downloading and extraction in proper path, along with operating system package management.
Every platform in the repository extends the base-platform adding the specifics of each platform. They are a great way to learn how to create a new one.
An example¶
Let’s supose we wanted to create a nodejs platform. First, let’s define it’s Dockerfile:
FROM tsuru/base-platform
ADD . /var/lib/tsuru/nodejs
RUN cp /var/lib/tsuru/nodejs/deploy /var/lib/tsuru
RUN /var/lib/tsuru/nodejs/install
In this file, we are extending the tsuru/base-platform
, adding our deploy and install
scripts to the right place: /var/lib/tsuru
.
The install script runs when we add or update the platform on tsuru. It’s the perfect place to install dependencies that every application on it’s platform needs:
#!/bin/bash -le
SOURCE_DIR=/var/lib/tsuru
source ${SOURCE_DIR}/base/rc/config
apt-get update
apt-get install git -y
git clone https://github.com/creationix/nvm.git /etc/nvm
cd /etc/nvm && git checkout `git describe --abbrev=0 --tags`
cat >> ${HOME}/.profile <<EOF
if [ -e ${HOME}/.nvm_bin ]; then
export PATH="${HOME}/.nvm_bin:$PATH"
fi
EOF
As it can be seen, we are just installing some dependencies and preparing the environment for our applications.
The ${SOURCE_DIR}/base/rc/config
provides some bootstrap configuration that are usually needed.
Now, let’s define our deploy script, which runs every time a deploy occurs:
#!/bin/bash -le
SOURCE_DIR=/var/lib/tsuru
source ${SOURCE_DIR}/base/rc/config
source ${SOURCE_DIR}/base/deploy
export NVM_DIR=${HOME}/.nvm
[ ! -e ${NVM_DIR} ] && mkdir -p ${NVM_DIR}
. /etc/nvm/nvm.sh
nvm install stable
rm -f ~/.nvm_bin
ln -s $NVM_BIN ~/.nvm_bin
if [ -f ${CURRENT_DIR}/package.json ]; then
pushd $CURRENT_DIR && npm install --production
popd
fi
Once again we run some base scripts to do some heavy lifting: ${SOURCE_DIR}/base/rc/config
and
${SOURCE_DIR}/base/deploy
. After that, it’s just a matter of application specifics dependencies using
npm.
Now, we can move on and add our newly created platform.
Adding your platform to tsuru¶
After creating you platform as a Dockerfile, you can add it to tsuru using the client:
$ tsuru platform-add your-platform-name --dockerfile http://url-to-dockerfile
If you push your image to an Docker Registry, you can use:
$ tsuru platform-add your-platform-name -i your-user/image-name