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anodizer_core/
content_source.rs

1//! Resolve a [`ContentSource`] to its string content.
2//!
3//! Hoisted to core so multiple stages (release, changelog, ...) can share one
4//! implementation. Supports `Inline`, `FromFile` (template-render the path,
5//! read the file), and `FromUrl` (template-render URL + headers, fetch via
6//! HTTP GET with retries on transient errors / 5xx, fail fast on 4xx).
7//!
8//! `FromUrl` enforces a 256 KiB body cap and rejects CR/LF in rendered header
9//! values to defend against header-injection via templated user data.
10
11use std::time::Duration;
12
13use anyhow::{Context as _, Result};
14
15use crate::config::ContentSource;
16use crate::context::Context;
17use crate::retry::{RetryPolicy, SuccessClass, retry_http_blocking};
18
19const MAX_BODY_BYTES: usize = 256 * 1024;
20/// Total per-request deadline. `reqwest::blocking::ClientBuilder` does
21/// not expose a separate `read_timeout` (the API is async-only); the
22/// total `timeout` bounds connect + transfer for the blocking surface,
23/// so a stalled server cannot hold the connection open past 30 s.
24const HTTP_TIMEOUT: Duration = Duration::from_secs(30);
25/// Connect-only deadline. Allows the connect phase to fail fast on a
26/// dead host without consuming the full request budget; the remaining
27/// time is then available for the actual transfer.
28const HTTP_CONNECT_TIMEOUT: Duration = Duration::from_secs(10);
29const POLICY: RetryPolicy = RetryPolicy {
30    max_attempts: 3,
31    base_delay: Duration::from_millis(500),
32    max_delay: Duration::from_secs(2),
33};
34
35/// Resolve a [`ContentSource`] to its string content.
36///
37/// `kind` is a short label (e.g. `"release header"`, `"changelog footer"`)
38/// surfaced in error messages so misconfigured fields are easy to identify.
39pub fn resolve(source: &ContentSource, kind: &str, ctx: &Context) -> Result<String> {
40    match source {
41        ContentSource::Inline(s) => Ok(s.clone()),
42        ContentSource::FromFile { from_file } => {
43            let rendered_path = ctx
44                .render_template(from_file)
45                .with_context(|| format!("{kind}: render from_file path '{from_file}'"))?;
46            std::fs::read_to_string(&rendered_path)
47                .with_context(|| format!("{kind}: read from_file '{rendered_path}'"))
48        }
49        ContentSource::FromUrl { from_url, headers } => {
50            let rendered_url = ctx
51                .render_template(from_url)
52                .with_context(|| format!("{kind}: render from_url '{from_url}'"))?;
53
54            // Render header values (keys are literal per GoReleaser docs).
55            // Reject CR/LF anywhere in keys or rendered values — a template
56            // interpolating user-tainted data could otherwise inject a new
57            // header line.
58            let mut rendered_headers: Vec<(String, String)> = Vec::new();
59            if let Some(map) = headers {
60                for (k, v) in map {
61                    if k.contains('\r') || k.contains('\n') {
62                        anyhow::bail!(
63                            "{kind} from_url header key contains CR/LF (possible injection): {:?}",
64                            k
65                        );
66                    }
67                    let rendered_v = ctx.render_template(v).with_context(|| {
68                        format!("{kind}: render header value for '{k}' at URL {rendered_url}")
69                    })?;
70                    if rendered_v.contains('\r') || rendered_v.contains('\n') {
71                        anyhow::bail!(
72                            "{kind} from_url header '{}' rendered to a value containing \
73                             CR/LF (possible injection): {:?}",
74                            k,
75                            rendered_v
76                        );
77                    }
78                    rendered_headers.push((k.clone(), rendered_v));
79                }
80            }
81
82            let client = reqwest::blocking::Client::builder()
83                .user_agent(crate::http::USER_AGENT)
84                .timeout(HTTP_TIMEOUT)
85                .connect_timeout(HTTP_CONNECT_TIMEOUT)
86                .build()
87                .context("build blocking HTTP client for ContentSource::FromUrl")?;
88
89            // `retry_http_blocking` handles 5xx → retry, 4xx → fast-fail, and
90            // transport errors via the shared `is_retriable` classifier.
91            // Body-cap and label-formatting are applied on the returned
92            // body string.
93            let label = format!("{kind} from_url {rendered_url}");
94            let rendered_url_for_err = rendered_url.clone();
95            let (_status, body) = retry_http_blocking(
96                &label,
97                &POLICY,
98                SuccessClass::Strict,
99                |_attempt| {
100                    let mut req = client.get(&rendered_url);
101                    for (k, v) in &rendered_headers {
102                        req = req.header(k.as_str(), v.as_str());
103                    }
104                    req.send()
105                },
106                |status, _body| format!("returned HTTP {status}"),
107            )?;
108
109            if body.len() > MAX_BODY_BYTES {
110                anyhow::bail!(
111                    "{kind} from_url {} body is {} bytes, exceeds {} KiB limit",
112                    rendered_url_for_err,
113                    body.len(),
114                    MAX_BODY_BYTES / 1024,
115                );
116            }
117            Ok(body)
118        }
119    }
120}