turnout 0.24.0

A developer's switchyard: point local apps at any backend stand, keep servers and secrets at hand, build and deploy from any directory
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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166

use anyhow::Result;
use serde::Serialize;

use crate::cli::Format;
use crate::progress::Step;
use crate::{output, remote};

/// The newest backup in a directory listing.
///
/// Backup names are `YYYYMMDD-HHMMSS.tar.gz`, so the newest is simply the
/// largest string - no date parsing, and no dependence on the order the server
/// happened to list them in (`dir /b` and `ls -1` do not agree on that).
///
/// Anything that is not a backup name is ignored rather than trusted: the
/// directory belongs to the user, and a stray note in it must not be restored
/// as if it were an archive.
fn newest(listing: &str) -> Option<&str> {
    listing.lines().map(str::trim).filter(|line| is_backup_name(line)).max()
}

/// Whether a listing entry is one of our archives: `YYYYMMDD-HHMMSS.tar.gz`.
fn is_backup_name(entry: &str) -> bool {
    let Some(stem) = entry.strip_suffix(".tar.gz") else {
        return false;
    };
    let bytes = stem.as_bytes();
    bytes.len() == 15 && bytes[8] == b'-' && stem.chars().enumerate().all(|(i, c)| if i == 8 { c == '-' } else { c.is_ascii_digit() })
}

pub fn backup(target_name: Option<String>, overrides: remote::Overrides) -> Result<()> {
    let target = remote::resolve(target_name, overrides)?;
    let dir = &target.path.dir;
    let step = Step::start(format!("Connecting to {} ...", target.connection_label()));
    let session = remote::connect(&target.server, &target.credential)?;
    let dialect = remote::dialect(&session, &target.server);
    step.update(format!("Backing up {dir} ..."));
    let name = remote::run_backup(&session, dialect, dir)?;
    step.done(format!("Backup {} created in {}", name.trim(), remote::backups_dir(dir)));
    crate::journal::record("backup", Some(&target.app.name), Some(&target.server.name), Some(name.trim()));
    Ok(())
}

/// The backups `restore --list` reports: the archives in a target's backup
/// directory, newest first.
#[derive(Serialize)]
struct Backups {
    dir: String,
    backups: Vec<String>,
}

/// Our archives in a directory listing, newest first; anything else in the
/// directory is the user's and stays out.
fn archives(listing: &str) -> Vec<String> {
    let mut names: Vec<String> = listing.lines().map(str::trim).filter(|line| is_backup_name(line)).map(str::to_string).collect();
    names.sort_unstable_by(|a, b| b.cmp(a));
    names
}

/// `restore`; `list` is `Some` with how to print the list when only listing.
pub fn restore(target_name: Option<String>, overrides: remote::Overrides, from: Option<String>, list: Option<Format>) -> Result<()> {
    let target = remote::resolve(target_name, overrides)?;
    let deploy_dir = target.path.dir.clone();
    let backups_raw = remote::backups_dir(&deploy_dir);
    let step = Step::start(format!("Connecting to {} ...", target.connection_label()));
    let session = remote::connect(&target.server, &target.credential)?;
    let dialect = remote::dialect(&session, &target.server);
    remote::check_quotable(dialect, &[&deploy_dir, &backups_raw])?;
    step.clear();

    if let Some(format) = list {
        let listing = remote::exec(&session, &dialect.list_dir(&backups_raw))?;
        let backups = Backups {
            backups: archives(&listing),
            dir: backups_raw,
        };
        let app = target.app.name.clone();
        return output::emit(format, &backups, |backups| {
            if backups.backups.is_empty() {
                return format!("No backups yet in {} - create one with `turnout backup {app}`.", backups.dir);
            }
            backups.backups.join("\n")
        });
    }

    let name = match from {
        Some(name) => name,
        None => {
            // Sorted here rather than by piping through `sort | tail` on the
            // server: that pipeline is POSIX-only, and the names are fixed-width
            // timestamps, so lexicographic order is chronological order.
            let listing = remote::exec(&session, &dialect.list_dir(&backups_raw))?;
            newest(&listing)
                .ok_or_else(|| anyhow::anyhow!("no backups in {backups_raw} - create one with `turnout backup {}`", target.app.name))?
                .to_string()
        }
    };
    let step = Step::start(format!("Restoring {name} into {deploy_dir} ..."));
    remote::restore_backup(&session, dialect, &deploy_dir, &name)?;
    step.done(format!("Restored {name} into {deploy_dir}"));
    crate::journal::record("restore", Some(&target.app.name), Some(&target.server.name), Some(&name));
    if let Some(restart) = &target.path.restart {
        // The same post-write command a deploy runs, run the same way: in the
        // deploy directory, and detached from this connection. Until v0.24 a
        // restore ran it in the home directory, which a deploy stopped doing
        // in v0.11.
        let mut session = session;
        let connect = || remote::connect(&target.server, &target.credential);
        let step = Step::start(format!("Running: {restart}"));
        let output = remote::restart(&mut session, dialect, &target.path, restart, &connect, |line| {
            step.update(format!("Running: {restart} ยท {line}"))
        })?;
        step.done(format!("Restarted: {restart}"));
        if !output.trim().is_empty() {
            println!("{}", output.trim_end());
        }
    }
    Ok(())
}

#[cfg(test)]
mod tests {
    use super::{is_backup_name, newest};

    /// The newest backup is picked from the listing, not from its order: `ls -1`
    /// sorts, `dir /b` does not, and restore must land on the same archive
    /// either way.
    #[test]
    fn the_newest_backup_wins_regardless_of_listing_order() {
        let shuffled = "20260810-120000.tar.gz\n20260812-181500.tar.gz\n20260811-090000.tar.gz\n";
        assert_eq!(newest(shuffled), Some("20260812-181500.tar.gz"));

        // Windows line endings, since the listing may come from cmd.exe.
        let crlf = "20260810-120000.tar.gz\r\n20260812-181500.tar.gz\r\n";
        assert_eq!(newest(crlf), Some("20260812-181500.tar.gz"));
    }

    /// Same day, different times: the sort has to reach into the time field.
    #[test]
    fn backups_from_the_same_day_compare_by_time() {
        let listing = "20260812-090000.tar.gz\n20260812-181500.tar.gz\n20260812-093000.tar.gz";
        assert_eq!(newest(listing), Some("20260812-181500.tar.gz"));
    }

    /// The backups directory belongs to the user. A file they left in it must
    /// never be handed to `tar` as if turnout had written it.
    #[test]
    fn only_our_own_archives_are_candidates() {
        assert!(is_backup_name("20260812-181500.tar.gz"));
        assert!(!is_backup_name("notes.txt"));
        assert!(!is_backup_name("site-final.tar.gz"), "not a timestamp");
        assert!(!is_backup_name("20260812-181500.zip"));
        assert!(!is_backup_name("2026081-181500.tar.gz"), "wrong width");

        let mixed = "readme.txt\n20260812-181500.tar.gz\nold-backup.tar.gz\n";
        assert_eq!(newest(mixed), Some("20260812-181500.tar.gz"));
    }

    /// An empty or backup-less listing is a normal state - it means nobody has
    /// taken one yet, and the caller turns that into an explanation.
    #[test]
    fn nothing_to_restore_is_not_a_backup() {
        assert_eq!(newest(""), None);
        assert_eq!(newest("   \n\n"), None);
        assert_eq!(newest("readme.txt\n"), None);
    }
}