1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149

//! Edge SSH command.

use anyhow::Context;
use wasmer_backend_api::WasmerClient;

use super::AsyncCliCommand;
use crate::{config::WasmerEnv, edge_config::EdgeConfig};

/// Start a remote SSH session.
#[derive(clap::Parser, Debug)]
pub struct CmdSsh {
    #[clap(flatten)]
    env: WasmerEnv,
    /// SSH port to use.
    #[clap(long, default_value = "22")]
    pub ssh_port: u16,
    /// Local port mapping to the package that's running, this allows
    /// for instance a HTTP server to be tested remotely while giving
    /// instant logs over stderr channelled via SSH.
    #[clap(long)]
    pub map_port: Vec<u16>,
    /// Package to run on the Deploy servers
    ///
    /// By default a bash session will be started.
    #[clap(index = 1)]
    pub run: Option<String>,

    /// Additional arguments to pass to the package.
    #[clap(index = 2, trailing_var_arg = true)]
    pub run_args: Vec<String>,

    /// The Edge SSH server host to connect to.
    ///
    /// You can usually ignore this flag, it mainly exists for debugging purposes.
    #[clap(long)]
    pub host: Option<String>,

    /// Prints the SSH command rather than executing it.
    #[clap(short, long)]
    pub print: bool,
}

impl CmdSsh {
    /// The default package to run.
    const DEFAULT_PACKAGE: &'static str = "wasmer/bash";
}

#[async_trait::async_trait]
impl AsyncCliCommand for CmdSsh {
    type Output = ();

    async fn run_async(self) -> Result<(), anyhow::Error> {
        let mut config = crate::edge_config::load_config(None)?;
        let client = self.env.client()?;

        let (token, is_new) = acquire_ssh_token(&client, &config.config).await?;

        let host = if let Some(host) = self.host {
            host
        } else {
            // No custom host specified, use an appropriate one based on the
            // environment.
            self.env
                .app_domain()
                .context("Could not determine SSH host based on the backend url")?
        };
        let port = self.ssh_port;

        if is_new {
            eprintln!("Acquired new SSH token");
            config.set_ssh_token(token.clone())?;
            if let Err(err) = config.save() {
                eprintln!("WARNING: failed to save config: {err}");
            }
        }

        let mut cmd = std::process::Command::new("ssh");
        let mut cmd = cmd
            .args([
                // No controlpath becaue we don't want to re-use connections
                "-o",
                "ControlPath=none",
                // Disable host key checking, because we use a DNS-load-balanced
                // host.
                "-o",
                "StrictHostKeyChecking=no",
                // Don't persist known hosts - don't want to clutter users
                // regular ssh data.
                "-o",
                "UserKnownHostsFile=/dev/null",
                "-o",
                "IdentitiesOnly=yes",
                // Don't print ssh related output.
                "-q",
            ])
            .args(["-p", format!("{port}").as_str()]);
        for map_port in self.map_port {
            cmd = cmd.args(["-L", format!("{map_port}:localhost:{map_port}").as_str()]);
        }

        let package = self.run.as_deref().unwrap_or(Self::DEFAULT_PACKAGE);
        cmd = cmd.arg(format!("{token}@{host}")).arg(package);
        for run_arg in self.run_args {
            cmd = cmd.arg(&run_arg);
        }

        if self.print {
            print!("ssh");
            for arg in cmd.get_args() {
                print!(" {}", arg.to_string_lossy().as_ref());
            }
            println!();
            return Ok(());
        }

        let exit = cmd.spawn()?.wait()?;
        if exit.success() {
            Ok(())
        } else {
            Err(anyhow::anyhow!("ssh failed with status {}", exit))
        }
    }
}

type IsNew = bool;
type RawToken = String;

async fn acquire_ssh_token(
    client: &WasmerClient,
    config: &EdgeConfig,
) -> Result<(RawToken, IsNew), anyhow::Error> {
    if let Some(token) = &config.ssh_token {
        // TODO: validate that token is still valid.
        return Ok((token.clone(), false));
    }

    let token = create_ssh_token(client).await?;
    Ok((token, true))
}

/// Create a new token for SSH access through the backend API.
async fn create_ssh_token(client: &WasmerClient) -> Result<RawToken, anyhow::Error> {
    wasmer_backend_api::query::generate_deploy_config_token_raw(
        client,
        wasmer_backend_api::query::TokenKind::SSH,
    )
    .await
    .context("Could not create token for ssh access")
}