# nsc ssh

Connect to ephemeral environments.

`ssh` connects to a previously created ephemeral environment. It establishes a
`ssh` connection to the target environment, over Namespace's networking, in a
way that end-to-end encryption is retained, but the target host is not exposed
directly to the Internet.

To enable experimentation, `ssh` also has a "quick create" mode built-in,
allowing you to quickly create a named environment (a sandbox), or get back to a
previously created sandbox.

This allows you to jump into a container-enabled terminal in a few seconds.

## Usage

```bash theme={null}
nsc ssh [--container_name <name>] [-T] [-t] [--oneshot] [-A] [--unique_tag <name>] [<id>] [command]
```

### Example

#### 1. Create an ephemeral instance

Create an ephemeral instance and note its ID:

```bash theme={null}
nsc create
```

```text nocopy Output theme={null}
Created new ephemeral environment! ID: 85a32emcg99ii
```

#### 2. Connect to the instance

Connect to the instance using its ID:

```bash theme={null}
nsc ssh 85a32emcg99ii
```

```text nocopy Output theme={null}
85a32emcg99ii:~#
```

#### 3. Select an instance interactively

Omit the instance ID to select from a list of your instances:

```bash theme={null}
nsc ssh
```

```text nocopy Output theme={null}
┌─────────────────────────────────────────────────────────────────────────────────┐
│ Instance ID    CPU  Memory   Arch   Created       Time to live         Purpose  │
│─────────────────────────────────────────────────────────────────────────────────│
│ 85a32emcg99ii  4    4.0 GiB  amd64  10 hours ago  29 minutes from now  ...      │
└─────────────────────────────────────────────────────────────────────────────────┘
```

#### 4. Run a remote command

Run a command directly in the instance through `nsc ssh`:

```bash theme={null}
nsc ssh 85a32emcg99ii ls /
```

```text nocopy Output theme={null}
bin         etc         lib         media       nsc         proc        run         srv         tmp         var
dev         home        lost+found  mnt         opt         root        sbin        sys         usr         vendor
```

## Options

### --container_name <name>

Connects to the container named `name` in the environment, instead of the
instance environment itself.

On a GitHub Actions runner instance, use `--container_name github-runner` to
connect to the runner container while it is handling a job.

### --disable-pty, -T

Disables allocation of a pseudo-terminal for the SSH session. This is useful
when running a non-interactive command whose output you're piping elsewhere,
where a TTY would otherwise introduce unwanted formatting.

### --force-pty, -t

Forces allocation of a pseudo-terminal, even when running a non-interactive
command. This is useful for commands that expect a terminal to be present,
such as ones that produce colored output or otherwise behave differently
without one.

### --oneshot

If specified, a temporary instance is created for the SSH session and
destroyed as soon as you disconnect. This is convenient for quick, one-off
experiments where you don't want the instance to stick around afterward.

### --ssh_agent, -A

Forward your local SSH agent connection, to the remote environment.

### --unique_tag <name>

If specified, creates an instance with the specified unique tag, so you can
identify or reference that specific environment later.