webserver_base/webserver/
error.rs

1//! The web server's error type.
2
3use std::net::SocketAddr;
4
5use axum::http::StatusCode;
6use axum::response::{IntoResponse, Response};
7use tracing::error;
8
9use crate::env::EnvError;
10
11/// Every way the web server can fail.
12///
13/// Composed from the per-kit errors rather than replacing them: a crate on only
14/// `telegram` sees [`TelegramError`](crate::telegram::TelegramError) and never
15/// this type. Deliberately not `#[non_exhaustive]`.
16#[derive(thiserror::Error)]
17pub enum WebServerError {
18    /// A required environment variable was missing or malformed.
19    #[error(transparent)]
20    Env(#[from] EnvError),
21
22    /// The listener could not bind.
23    #[error("failed to bind to {addr}")]
24    Bind {
25        addr: SocketAddr,
26        #[source]
27        source: std::io::Error,
28    },
29
30    /// The browser Sentry DSN could not be parsed.
31    #[cfg(feature = "analytics")]
32    #[error("the browser Sentry DSN is malformed")]
33    SentryDsn(#[from] crate::analytics::SentryDsnParseError),
34
35    /// The server stopped with an error rather than a shutdown.
36    #[error("the server stopped unexpectedly")]
37    Serve(#[source] std::io::Error),
38
39    /// A template could not be loaded or rendered.
40    #[cfg(feature = "templates")]
41    #[error(transparent)]
42    Template(#[from] crate::templates::TemplateError),
43
44    /// A render was attempted without `.templates(..)` having been called.
45    #[cfg(feature = "templates")]
46    #[error("cannot render: the server was built without `.templates(..)`")]
47    TemplatesNotConfigured,
48
49    /// The asset cache could not be built.
50    #[cfg(feature = "webserver")]
51    #[error(transparent)]
52    CacheBuster(#[from] crate::assets::CacheBusterError),
53
54    /// The sitemap could not be written.
55    #[cfg(feature = "sitemap")]
56    #[error(transparent)]
57    Sitemap(#[from] crate::sitemap::SitemapError),
58
59    /// Observability could not be configured.
60    #[cfg(feature = "observability")]
61    #[error(transparent)]
62    Observability(#[from] crate::observability::ObservabilityError),
63
64    /// Pages were declared without the template data needed to render or list
65    /// them.
66    #[cfg(feature = "pages")]
67    #[error("`.pages(..)` requires `.templates(..)`: the sitemap needs the site's base url")]
68    PagesRequireTemplates,
69
70    /// A parameterised path was declared as a single page. `/blog/{slug}`
71    /// matches many URLs, so it cannot be one sitemap entry.
72    #[cfg(feature = "pages")]
73    #[error(
74        "page path `{path}` contains a route parameter; \
75         use `dynamic_page_group` with concrete urls, or mark it unlisted"
76    )]
77    DynamicPagePathHasParameters { path: String },
78}
79
80impl IntoResponse for WebServerError {
81    /// The body says nothing beyond "internal error"; the detail goes to the log.
82    fn into_response(self) -> Response {
83        error!("request failed: {self}");
84        (StatusCode::INTERNAL_SERVER_ERROR, "internal server error").into_response()
85    }
86}
87
88/// Renders the whole error chain, not the enum's shape.
89///
90/// `main` returning a `Result` prints its error with `Debug`, so a derived one
91/// would surface `CacheBuster(AmbiguousFavicon)` — the variant name — and throw
92/// away the sentence that says what to do about it. Every message in this crate
93/// is written for a human who has just had a boot fail; this is what makes them
94/// visible.
95impl std::fmt::Debug for WebServerError {
96    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
97        writeln!(f, "{self}")?;
98
99        let mut source: Option<&(dyn std::error::Error + 'static)> =
100            std::error::Error::source(self);
101        while let Some(error) = source {
102            writeln!(f, "  caused by: {error}")?;
103            source = error.source();
104        }
105        Ok(())
106    }
107}
webserver_base/webserver/error.rs

webserver_base/webserver/
error.rs
