A layer
for AWS Lambda that allows your functions to use git and ssh binaries.
You can add this layer to any Lambda function you want – no matter what runtime
you're using (EDIT 2019-05-16: as the new nodejs10.x runtime uses a completely different OS, this layer is not yet compatible with that runtime. Follow lambci#13 for updates). PATH already includes /opt/bin in Lambda, which is where it will be mounted.
Click on Layers and choose "Add a layer", and "Provide a layer version
ARN" and enter the following ARN (replace us-east-1 with the region of your Lambda):
arn:aws:lambda:us-east-1:553035198032:layer:git:5
Then click Add, save your lambda and test it out!
const { execSync } = require('child_process')
exports.handler = async(event) => {
execSync('rm -rf /tmp/*', { encoding: 'utf8', stdio: 'inherit' })
execSync('cd /tmp && git clone https://github.com/mhart/aws4', { encoding: 'utf8', stdio: 'inherit' })
return execSync('ls /tmp/aws4', { encoding: 'utf8' }).split('\n')
}const fs = require('fs')
const { execSync } = require('child_process')
exports.handler = async(event) => {
execSync('rm -rf /tmp/*', { encoding: 'utf8', stdio: 'inherit' })
fs.writeFileSync('/tmp/known_hosts', 'github.com,192.30.252.*,192.30.253.*,192.30.254.*,192.30.255.* ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==')
// Get this from a safe place, say SSM
fs.writeFileSync('/tmp/id_rsa', `-----BEGIN RSA PRIVATE KEY-----
...
-----END RSA PRIVATE KEY-----
`)
execSync('chmod 400 /tmp/id_rsa', { encoding: 'utf8', stdio: 'inherit' })
process.env.GIT_SSH_COMMAND = 'ssh -o UserKnownHostsFile=/tmp/known_hosts -i /tmp/id_rsa'
execSync('git clone --depth 1 ssh://git@github.com/mhart/aws4.git /tmp/aws4', { encoding: 'utf8', stdio: 'inherit' })
return execSync('ls /tmp/aws4', { encoding: 'utf8' }).split('\n')
}ssh always tries to create a .ssh directory – this is something you can't avoid, nor can you specify your own destination for this – which means you'll see a warning similar to the following:
Could not create directory '/home/sbx_user1075/.ssh'.
You can ignore this warning – ssh should continue to execute past this point, assuming you have the UserKnownHostsFile option correct and it contains the signature of the host you're trying to connect to. Alternatively, you can use -o StrictHostKeyChecking=no if you're not concerned about MiTM attacks.
| Git version | openssh version | ARN |
|---|---|---|
| 2.21.0 | OpenSSH_6.6.1p1, OpenSSL 1.0.1k-fips | arn:aws:lambda:<region>:553035198032:layer:git:5 |
| 2.20.0 | OpenSSH_6.6.1p1, OpenSSL 1.0.1k-fips | arn:aws:lambda:<region>:553035198032:layer:git:3 |
| 2.19.2 | OpenSSH_6.6.1p1, OpenSSL 1.0.1k-fips | arn:aws:lambda:<region>:553035198032:layer:git:2 |