Creating a pre-receive hook environment

In this article

• Creating a pre-receive hook environment using Docker
• Creating a pre-receive hook environment using chroot
• Uploading a pre-receive hook environment on GitHub Enterprise Server
• Uploading a pre-receive hook environment via the administrative shell

A pre-receive environment for GitHub Enterprise Server is a Linux chroot environment. Because pre-receive hooks execute on every push event, they should be fast and lightweight. The environment needed for such checks will typically be minimal.

GitHub Enterprise Server provides a default environment which includes these packages: awk, bash, coreutils, curl, find, gnupg, grep, jq, sed.

If you have a specific requirement that isn't met by this environment, such as support for a particular language, you can create and upload your own 64-bit Linux chroot environment.

Creating a pre-receive hook environment using Docker

You can use a Linux container management tool to build a pre-receive hook environment. This example uses Alpine Linux and Docker.

1. Ensure Docker is installed locally.

2. Create the file Dockerfile.alpine-3.3 that contains this information:

   FROM gliderlabs/alpine:3.3
   RUN apk add --no-cache git bash
   

3. From the working directory that contains Dockerfile.alpine-3.3, build an image:

   $ docker build -f Dockerfile.alpine-3.3 -t pre-receive.alpine-3.3 .
   > Sending build context to Docker daemon 12.29 kB
   > Step 1 : FROM gliderlabs/alpine:3.3
   >  ---> 8944964f99f4
   > Step 2 : RUN apk add --no-cache git bash
   >  ---> Using cache
   >  ---> 0250ab3be9c5
   > Successfully built 0250ab3be9c5

4. Create a container:

   $ docker create --name pre-receive.alpine-3.3 pre-receive.alpine-3.3 /bin/true

5. Export the Docker container to a gzip compressed tar file:

   $ docker export pre-receive.alpine-3.3 | gzip > alpine-3.3.tar.gz

   This file alpine-3.3.tar.gz is ready to be uploaded to the GitHub Enterprise Server appliance.

Creating a pre-receive hook environment using chroot

1. Create a Linux chroot environment.

2. Create a gzip compressed tar file of the chroot directory.

   $ cd /path/to/chroot
   $ tar -czf /path/to/pre-receive-environment.tar.gz .

   Notes:

   • Do not include leading directory paths of files within the tar archive, such as /path/to/chroot.
   • /bin/sh must exist and be executable, as the entry point into the chroot environment.
   • Unlike traditional chroots, the dev directory is not required by the chroot environment for pre-receive hooks.

For more information about creating a chroot environment see "Chroot" from the Debian Wiki, "BasicChroot" from the Ubuntu Community Help Wiki, or "Installing Alpine Linux in a chroot" from the Alpine Linux Wiki.

Uploading a pre-receive hook environment on GitHub Enterprise Server

1. In the upper-right corner of any page, click .

   

2. In the left sidebar, click Business.

   

3. Under your business account's name, click Settings.

   

4. In the left sidebar, click Hooks.

   

5. Click Manage environments.

   

6. Click Add environment.

   

7. Enter the desired name in the Environment name field.

   

8. Enter the URL of the *.tar.gz file that contains your environment.

   

9. Click Add environment.

   

Uploading a pre-receive hook environment via the administrative shell

1. Upload a readable *.tar.gz file that contains your environment to a web host and copy the URL or transfer the file to the GitHub Enterprise Server appliance via scp. When using scp, you may need to adjust the *.tar.gz file permissions so that the file is world readable.

2. Connect to the administrative shell.

3. Use the ghe-hook-env-create command and type the name you want for the environment as the first argument and the full local path or URL of a *.tar.gz file that contains your environment as the second argument.

   admin@ghe-host:~$ ghe-hook-env-create AlpineTestEnv /home/admin/alpine-3.3.tar.gz
   > Pre-receive hook environment 'AlpineTestEnv' (2) has been created.