git.r.bdr.sh - rbdr/olden-mail/blob - src/configuration.rs

   1 //! # Configuration
   2 //!
   3 //! This module defines the configuration used to initialize both proxies.
   4
   5 use log::error;
   6 use std::env;
   7 use std::fmt::Debug;
   8 use std::sync::Arc;
   9 use thiserror::Error;
  10
  11 #[derive(Error, Debug)]
  12 pub enum Error {
  13     #[error("Environment variable {0} not set.")]
  14     MissingEnvVar(String),
  15     #[error("Failed to parse {0}.")]
  16     ParseError(String),
  17 }
  18
  19 /// Configuration for any proxy
  20 #[derive(Debug)]
  21 pub struct Proxy {
  22     pub local_port: u16,
  23     pub bind_address: String,
  24     pub remote_host: String,
  25     pub remote_port: u16,
  26     pub protocol: &'static str,
  27 }
  28
  29 /// Aggregated configuration for both proxies, already in a reference counter.
  30 pub struct Configuration {
  31     pub imap_configuration: Arc<Proxy>,
  32     pub smtp_configuration: Arc<Proxy>,
  33 }
  34
  35 impl Configuration {
  36     /// Creates a new configuration object by reading the environment
  37     /// variables. Exits if the right ones aren't found.
  38     pub fn new() -> Result<Self, Error> {
  39         Ok(Configuration {
  40             imap_configuration: Arc::new(Proxy {
  41                 local_port: get_env_number("LOCAL_IMAP_PORT", 143)?,
  42                 bind_address: get_env_var("LOCAL_IMAP_BIND_ADDRESS", Some("0.0.0.0".to_string()))?,
  43                 remote_host: get_env_var("REMOTE_IMAP_DOMAIN", None)?,
  44                 remote_port: get_env_number("REMOTE_IMAP_PORT", 993)?,
  45                 protocol: "IMAP",
  46             }),
  47             smtp_configuration: Arc::new(Proxy {
  48                 local_port: get_env_number("LOCAL_SMTP_PORT", 25)?,
  49                 bind_address: get_env_var("LOCAL_SMTP_BIND_ADDRESS", Some("0.0.0.0".to_string()))?,
  50                 remote_host: get_env_var("REMOTE_SMTP_DOMAIN", None)?,
  51                 remote_port: get_env_number("REMOTE_SMTP_PORT", 993)?,
  52                 protocol: "SMTP",
  53             }),
  54         })
  55     }
  56 }
  57
  58 /// Get an environment variable or return an error.
  59 fn get_env_var(name: &str, default: Option<String>) -> Result<String, Error> {
  60     match env::var(name) {
  61         Ok(value) => Ok(value),
  62         Err(_) => match default {
  63             Some(default_value) => Ok(default_value),
  64             None => Err(Error::MissingEnvVar(name.to_string())),
  65         },
  66     }
  67 }
  68
  69 /// Get an environment variable and parse it as a number. Return a default
  70 /// if not set.
  71 fn get_env_number(name: &str, default: u16) -> Result<u16, Error> {
  72     match env::var(name) {
  73         Ok(value) => value
  74             .parse()
  75             .map_err(|_| Error::ParseError(name.to_string())),
  76         Err(_) => Ok(default),
  77     }
  78 }