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docs/references/baseimage.md

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+# Base Image
+
+## Overview
+
+The application's Dockerfile must specify the FROM base image to be `cloudron/base:0.8.1`.
+
+The base image already contains most popular software packages including node, nginx, apache,
+ruby, PHP. Using the base image greatly reduces the size of app images.
+
+The goal of the base image is simply to provide pre-downloaded software packages. The packages
+are not configured in any way and it's up to the application to configure them as they choose.
+For example, while `apache` is installed, there are no meaningful site configurations that the
+application can use.
+
+## Packages
+
+The following packages are part of the base image. If you need another version, you will have to
+install it yourself.
+
+* Apache 2.4.10
+* Composer 1.0 (alpha 10)
+* Go 1.5.1
+* Gunicorn 19.0.0
+* Java 1.7, JRE IcedTea 2.5.5
+* Maven 3.0.5
+* MySQL Client 5.6
+* nginx 1.6.2
+* Node 0.10.40, 0.12.7, 4.2.1 (installed under `/usr/local/node-<version>`) [more information](#node-js)
+* Perl 5.20.1
+* PHP 5.5.12
+* Postgresql client 9.4
+* Python 2.7.8
+* Ruby 2.1.2
+* sqlite3 3.8.6
+* Supervisor 3.0
+* uwsgi 2.0.6
+
+## Inspecting the base image
+
+The base image can be inspected by installing [Docker](https://docs.docker.com/installation/).
+
+Once installed, pull down the base image locally using the following command:
+```
+    docker pull cloudron/base:0.8.1
+```
+
+To inspect the base image:
+```
+    docker run -ti cloudron/base:0.8.1 /bin/bash
+```
+
+*Note:* Please use `docker 1.9.0` or above to pull the base image. Doing otherwise results in a base
+image with an incorrect image id. The image id of `cloudron/base:0.8.1` is `d038af182821`.
+
+## The `cloudron` user
+
+The base image contains a user named `cloudron` that apps can use to run their app.
+
+It is good security practice to run apps as a non-previleged user.
+
+## Env vars
+
+The following environment variables are set as part of the application runtime.
+
+### API_ORIGIN
+
+API_ORIGIN is set to the HTTP(S) origin of this Cloudron's API. For example,
+`https://my-girish.cloudron.us`.
+
+### APP_DOMAIN
+
+APP_DOMAIN is set to the domain name of the application. For example, `app-girish.cloudron.us`.
+
+### APP_ORIGIN
+
+APP_ORIGIN is set to the HTTP(S) origin on the application. This is origin which the
+user can use to reach the application. For example, `https://app-girish.cloudron.us`.
+
+### CLOUDRON
+
+CLOUDRON is always set to '1'. This is useful to write Cloudron specific code.
+
+### WEBADMIN_ORIGIN
+
+WEBADMIN_ORIGIN is set to the HTTP(S) origin of the Cloudron's web admin. For example,
+`https://my-girish.cloudron.us`.
+
+## Recipes
+
+We have collected some recipes for configuring popular packages [here](/references/recipes.html).
+
+## Node.js
+
+The base image comes pre-installed with various node.js versions.
+
+They can be used by adding `ENV PATH /usr/local/node-<version>/bin:$PATH`.
+
+Currently available versions are:
+ * 0.10.40
+ * 0.12.7
+ * 4.2.1