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GitHub Action

SSH Remote Commands

v1.0.1

SSH Remote Commands

terminal

SSH Remote Commands

Executing remote ssh commands

Installation

Copy and paste the following snippet into your .yml file.

              

- name: SSH Remote Commands

uses: appleboy/ssh-action@v1.0.1

Learn more about this action in appleboy/ssh-action

Choose a version

🚀 SSH for GitHub Actions

繁體中文

GitHub Action for executing remote ssh commands.

ssh workflow

Actions Status

Important: Only support Linux docker container.

This thing is built using Golang and drone-ssh. 🚀

Input variables

See action.yml for more detailed information.

Input Parameter Description Default Value
host SSH host address
port SSH port number 22
passphrase SSH key passphrase
username SSH username
password SSH password
sync Enable synchronous execution if multiple hosts false
use_insecure_cipher Include more ciphers with use_insecure_cipher false
cipher Allowed cipher algorithms. If unspecified, a sensible default
timeout Timeout duration for SSH to host 30s
command_timeout Timeout duration for SSH command 10m
key Content of SSH private key. e.g., raw content of ~/.ssh/id_rsa
key_path Path of SSH private key
fingerprint SHA256 fingerprint of the host public key
proxy_host SSH proxy host
proxy_port SSH proxy port 22
proxy_username SSH proxy username
proxy_password SSH proxy password
proxy_passphrase SSH proxy key passphrase
proxy_timeout Timeout for SSH to proxy host 30s
proxy_key Content of SSH proxy private key
proxy_key_path Path of SSH proxy private key
proxy_fingerprint SHA256 fingerprint of the proxy host public key
proxy_cipher Allowed cipher algorithms for the proxy
proxy_use_insecure_cipher Include more ciphers with use_insecure_cipher for the proxy false
script Execute commands
script_stop Stop script after first failure false
envs Pass environment variables to shell script
envs_format Flexible configuration of environment value transfer
debug Enable debug mode false
allenvs Pass all environment variables to shell script false

Usage

Executing remote ssh commands.

name: remote ssh command
on: [push]
jobs:

  build:
    name: Build
    runs-on: ubuntu-latest
    steps:
    - name: executing remote ssh commands using password
      uses: appleboy/ssh-action@v1.0.1
      with:
        host: ${{ secrets.HOST }}
        username: ${{ secrets.USERNAME }}
        password: ${{ secrets.PASSWORD }}
        port: ${{ secrets.PORT }}
        script: whoami

output:

======CMD======
whoami
======END======
out: ***
==============================================
✅ Successfully executed commands to all host.
==============================================

Setting up a SSH Key

Make sure to follow the below steps while creating SSH Keys and using them. The best practice is create the SSH Keys on local machine not remote machine. Login with username specified in Github Secrets. Generate a RSA Key-Pair:

Generate rsa key

ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

Generate ed25519 key

ssh-keygen -t ed25519 -a 200 -C "your_email@example.com"

Add newly generated key into Authorized keys. Read more about authorized keys here.

Add rsa key into Authorized keys

cat .ssh/id_rsa.pub | ssh b@B 'cat >> .ssh/authorized_keys'

Add ed25519 key into Authorized keys

cat .ssh/id_ed25519.pub | ssh b@B 'cat >> .ssh/authorized_keys'

Copy Private Key content and paste in Github Secrets.

Copy rsa Private key

clip < ~/.ssh/id_rsa

Copy ed25519 Private key

clip < ~/.ssh/id_ed25519

See the detail information about SSH login without password.

A note from one of our readers: Depending on your version of SSH you might also have to do the following changes:

  • Put the public key in .ssh/authorized_keys2
  • Change the permissions of .ssh to 700
  • Change the permissions of .ssh/authorized_keys2 to 640

If you are using OpenSSH

If you are currently using OpenSSH and are getting the following error:

ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey]

Make sure that your key algorithm of choice is supported. On Ubuntu 20.04 or later you must explicitly allow the use of the ssh-rsa algorithm. Add the following line to your OpenSSH daemon file (which is either /etc/ssh/sshd_config or a drop-in file under /etc/ssh/sshd_config.d/):

CASignatureAlgorithms +ssh-rsa

Alternatively, ed25519 keys are accepted by default in OpenSSH. You could use this instead of rsa if needed:

ssh-keygen -t ed25519 -a 200 -C "your_email@example.com"

Example

Executing remote ssh commands using password

- name: executing remote ssh commands using password
  uses: appleboy/ssh-action@v1.0.1
  with:
    host: ${{ secrets.HOST }}
    username: ${{ secrets.USERNAME }}
    password: ${{ secrets.PASSWORD }}
    port: ${{ secrets.PORT }}
    script: whoami

Using private key

- name: executing remote ssh commands using ssh key
  uses: appleboy/ssh-action@v1.0.1
  with:
    host: ${{ secrets.HOST }}
    username: ${{ secrets.USERNAME }}
    key: ${{ secrets.KEY }}
    port: ${{ secrets.PORT }}
    script: whoami

Multiple Commands

- name: multiple command
  uses: appleboy/ssh-action@v1.0.1
  with:
    host: ${{ secrets.HOST }}
    username: ${{ secrets.USERNAME }}
    key: ${{ secrets.KEY }}
    port: ${{ secrets.PORT }}
    script: |
      whoami
      ls -al

result

Multiple Hosts

  - name: multiple host
    uses: appleboy/ssh-action@v1.0.1
    with:
-     host: "foo.com"
+     host: "foo.com,bar.com"
      username: ${{ secrets.USERNAME }}
      key: ${{ secrets.KEY }}
      port: ${{ secrets.PORT }}
      script: |
        whoami
        ls -al

Multiple hosts with different port

  - name: multiple host
    uses: appleboy/ssh-action@v1.0.1
    with:
-     host: "foo.com"
+     host: "foo.com:1234,bar.com:5678"
      username: ${{ secrets.USERNAME }}
      key: ${{ secrets.KEY }}
      script: |
        whoami
        ls -al

Synchronous execution on multiple hosts

  - name: multiple host
    uses: appleboy/ssh-action@v1.0.1
    with:
      host: "foo.com,bar.com"
+     sync: true
      username: ${{ secrets.USERNAME }}
      key: ${{ secrets.KEY }}
      port: ${{ secrets.PORT }}
      script: |
        whoami
        ls -al

Pass environment variable to shell script

  - name: pass environment
    uses: appleboy/ssh-action@v1.0.1
+   env:
+     FOO: "BAR"
+     BAR: "FOO"
+     SHA: ${{ github.sha }}
    with:
      host: ${{ secrets.HOST }}
      username: ${{ secrets.USERNAME }}
      key: ${{ secrets.KEY }}
      port: ${{ secrets.PORT }}
+     envs: FOO,BAR,SHA
      script: |
        echo "I am $FOO"
        echo "I am $BAR"
        echo "sha: $SHA"

Inside env object, you need to pass every environment variable as a string, passing Integer data type or any other may output unexpected results.

Stop script after first failure

ex: missing abc folder

  - name: stop script if command error
    uses: appleboy/ssh-action@v1.0.1
    with:
      host: ${{ secrets.HOST }}
      username: ${{ secrets.USERNAME }}
      key: ${{ secrets.KEY }}
      port: ${{ secrets.PORT }}
+     script_stop: true
      script: |
        mkdir abc/def
        ls -al

output:

======CMD======
mkdir abc/def
ls -al

======END======
2019/11/21 01:16:21 Process exited with status 1
err: mkdir: cannot create directory ‘abc/def’: No such file or directory
##[error]Docker run failed with exit code 1

How to connect remote server using ProxyCommand?

+--------+       +----------+      +-----------+
| Laptop | <-->  | Jumphost | <--> | FooServer |
+--------+       +----------+      +-----------+

in your ~/.ssh/config, you will see the following.

Host Jumphost
  HostName Jumphost
  User ubuntu
  Port 22
  IdentityFile ~/.ssh/keys/jump_host.pem

Host FooServer
  HostName FooServer
  User ubuntu
  Port 22
  ProxyCommand ssh -q -W %h:%p Jumphost

How to convert to YAML format of GitHubActions

  - name: ssh proxy command
    uses: appleboy/ssh-action@v1.0.1
    with:
      host: ${{ secrets.HOST }}
      username: ${{ secrets.USERNAME }}
      key: ${{ secrets.KEY }}
      port: ${{ secrets.PORT }}
+     proxy_host: ${{ secrets.PROXY_HOST }}
+     proxy_username: ${{ secrets.PROXY_USERNAME }}
+     proxy_key: ${{ secrets.PROXY_KEY }}
+     proxy_port: ${{ secrets.PROXY_PORT }}
      script: |
        mkdir abc/def
        ls -al

Protecting a Private Key

The purpose of the passphrase is usually to encrypt the private key. This makes the key file by itself useless to an attacker. It is not uncommon for files to leak from backups or decommissioned hardware, and hackers commonly exfiltrate files from compromised systems.

  - name: ssh key passphrase
    uses: appleboy/ssh-action@v1.0.1
    with:
      host: ${{ secrets.HOST }}
      username: ${{ secrets.USERNAME }}
      key: ${{ secrets.KEY }}
      port: ${{ secrets.PORT }}
+     passphrase: ${{ secrets.PASSPHRASE }}
      script: |
        whoami
        ls -al

Using host fingerprint verification

Setting up SSH host fingerprint verification can help to prevent Person-in-the-Middle attacks. Before setting this up, run the command below to get your SSH host fingerprint. Remember to replace ed25519 with your appropriate key type (rsa, dsa, etc.) that your server is using and example.com with your host.

In modern OpenSSH releases, the default key types to be fetched are rsa (since version 5.1), ecdsa (since version 6.0), and ed25519 (since version 6.7).

ssh example.com ssh-keygen -l -f /etc/ssh/ssh_host_ed25519_key.pub | cut -d ' ' -f2

Now you can adjust you config:

  - name: ssh key passphrase
    uses: appleboy/ssh-action@v1.0.1
    with:
      host: ${{ secrets.HOST }}
      username: ${{ secrets.USERNAME }}
      key: ${{ secrets.KEY }}
      port: ${{ secrets.PORT }}
+     fingerprint: ${{ secrets.FINGERPRINT }}
      script: |
        whoami
        ls -al

Contributing

We would love for you to contribute to appleboy/ssh-action, pull requests are welcome!

License

The scripts and documentation in this project are released under the MIT License