shep 0.24.0

The shep binary: a process manager that keeps a flock of long-running processes alive on macOS, Linux and Windows, with logs, watch and cron restarts, and webhook alerts
Documentation 
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

//! `shep upgrade <dog> --rollback`: puts back the install the last upgrade
//! replaced, with its receipt.
//!
//! It swaps rather than discards: the install rolled away from becomes the one
//! a second `--rollback` returns to, so no build is lost.

use std::path::Path;

use shep_core::paths::ShepPaths;

use crate::cli::AdoptArgs;
use crate::exit::ExitCode;
use crate::output::Streams;

use super::adopt::{Flow, adopt_noting};
use super::consent::Input;
use super::dog_upgrade::{describe, fail_receipt, report_waiting, waiting_of};
use super::install::{Reach, lock_dog};
use super::install_keep::Kept;
use super::receipt::{self, Held};

/// `--rollback`: puts back the install the last upgrade replaced, and its receipt.
pub(super) async fn rollback(
    streams: &mut Streams<'_>,
    paths: &ShepPaths,
    reach: &Reach,
    input: &mut Input,
    name: &str,
    seen: &Held,
    enabled: bool,
) -> ExitCode {
    let _held = match lock_dog(streams, paths, name, reach.lock_wait).await {
        Ok(held) => held,
        Err(code) => return code,
    };
    // Read again under the lock.
    let current = match receipt::read(paths, name) {
        Ok(Some(current)) => current,
        Ok(None) => seen.clone(),
        Err(err) => return fail_receipt(streams, paths, name, &err),
    };
    let nothing = |streams: &mut Streams<'_>, why: &str| {
        streams.fail(
            ExitCode::Failure,
            &format!("nothing to roll `{name}` back to: {why}"),
        )
    };
    let Some(previous) = current.previous.clone() else {
        return nothing(streams, "the last install replaced nothing");
    };
    if !receipt::is_install_dir(paths, name, &previous) {
        return nothing(
            streams,
            &format!(
                "its receipt names {}, which is not one of its install directories",
                previous.display()
            ),
        );
    }
    let prior = match receipt::read_file(&previous.join("receipt.json")) {
        Ok(Some(prior)) => prior,
        Ok(None) => return nothing(streams, &format!("{} holds no receipt", previous.display())),
        Err(err) => {
            return nothing(
                streams,
                &format!("{}'s receipt does not read: {err}", previous.display()),
            );
        }
    };
    if !prior.binary.is_file() {
        return nothing(streams, &format!("{} is gone", prior.binary.display()));
    }
    let Some(current_root) = current
        .root()
        .filter(|root| receipt::is_install_dir(paths, name, root))
        .map(Path::to_path_buf)
    else {
        return nothing(
            streams,
            "the install it runs is not one of its install directories",
        );
    };
    if let Err(err) = receipt::write_document(
        &current_root.join("receipt.json"),
        &current.with_previous(None),
    ) {
        return streams.fail(
            ExitCode::Failure,
            &format!(
                "keeping the receipt of the install it leaves in {}: {err}",
                current_root.display()
            ),
        );
    }
    let receipt_file = receipt::receipt_path(paths, name);
    let kept = match Kept::park(&[&receipt_file]) {
        Ok(kept) => kept,
        Err(err) => {
            return streams.fail(
                ExitCode::Failure,
                &format!("setting aside the receipt of {name}: {err}"),
            );
        }
    };
    if let Err(err) =
        receipt::write_document(&receipt_file, &prior.with_previous(Some(&current_root)))
    {
        return streams.fail(
            ExitCode::Failure,
            &format!("writing {}: {err}", receipt_file.display()),
        );
    }
    let before = waiting_of(paths, name);
    let adopting = AdoptArgs {
        path: prior.binary.clone(),
        name: Some(name.to_owned()),
        yes: false,
    };
    let flow = Flow {
        verb: "upgrade",
        enable: enabled,
        restart: true,
    };
    let config_before = std::fs::read(&paths.daemon_config).ok();
    let code = adopt_noting(streams, paths, &adopting, input, flow, None, &mut false).await;
    if code == ExitCode::Success || std::fs::read(&paths.daemon_config).ok() != config_before {
        kept.commit();
    }
    if code == ExitCode::Success {
        streams.aside(
            "upgrade",
            &format!(
                "rolled {name} back from {} to {}",
                describe(&current.pinned),
                describe(&prior.pinned)
            ),
        );
        report_waiting(streams, paths, name, &before);
    }
    code
}