Offline Python Package Install Notes
====================================

Two common cases which make the install of Python packages harder due to networking issues are:
a) Install behind a Proxy
b) Install without access to the internet

## (a) Install behind a Proxy
In the case where the target machine connects to the internet over a network proxy, export the following environment vars, as appropriate - `http_proxy` and `https_proxy`. Eg:

```sh
$ export https_proxy=http://proxy.mydomain.com:<port>
$ export http_proxy=http://proxy.mydomain.com:<port>
$ pip install <package>
```

## (b) Install without access to the internet
In the case where the target machine does not have connectivity to the internet, you have to download the package and dependencies using a machine which does have connectivity to the internet. After which the install can follow. Sample instructions -

### Step 1. Download Packages for Offline Install
Execute the instructions below download the packages on a machine which is able to connect to the internet.

```sh
# if a single package is being installed
$ pip install <package> --download /tmp/offline_packages

# or, if a list of dependencies are to be installed
$ pip install --download /tmp/offline_packages -r requirements.txt
```

### Step 2. Transfer downloaded packages
Transfer downloaded packages to the target machine where the install is to be performed. Use scp/sftp/etc.

### Step 3. Install packages
Assuming the directory `/tmp/transferred_packages` contains the contents of `/tmp/offline_packages` from the earlier machine, execute the following steps on the the target machine.

```sh
# if a single package is being installed
$ pip install --no-index --find-links="/tmp/tranferred_packages" <package>

# if a list of dependencies are to be installed
$ pip install --no-index --find-links="/tmp/tranferred_packages" -r requirements.txt
```

----------

### References
[1]: http://stackoverflow.com/questions/7300321/how-to-use-pythons-pip-to-download-and-keep-the-zipped-files-for-a-package