Set up a file logger

Get a file path from the `LOG_FILE` environment variable and use it for
log output.

Call `database::get_database_connection()` and log the error if it
fails.

Worried about exiting early from the FastCGI program, as DreamHost says
this causes problems
(https://help.dreamhost.com/hc/en-us/articles/217298967). But I don't
see how the program can continue without a database connection.

Return a `Result` from `main()` because it's easier to use the `?`
operator for errors that happen before logging is initialised.

4 files changed, 43 insertions, 4 deletions

diff --git a/license-generator/src/database.rs b/license-generator/src/database.rs
index 28673c4..94e925f 100644
--- a/license-generator/src/database.rs
+++ b/license-generator/src/database.rs
@@ -4,7 +4,7 @@ use mysql;
 
 use errors::*;
 
-fn get_database_connection() -> Result<mysql::PooledConn> {
+pub fn get_database_connection() -> Result<mysql::PooledConn> {
     let connection_url = env::var("DATABASE_URL")?;
     let pool = mysql::Pool::new_manual(10, 50, connection_url)?;
     let cx = pool.get_conn()?;
diff --git a/license-generator/src/errors.rs b/license-generator/src/errors.rs
index 29f25ca..0a28341 100644
--- a/license-generator/src/errors.rs
+++ b/license-generator/src/errors.rs
@@ -1,9 +1,12 @@
+use log;
 use mysql;
 
 error_chain! {
     foreign_links {
         EnvVar(::std::env::VarError);
+        Io(::std::io::Error);
 
+        Log(log::SetLoggerError);
         MySql(mysql::error::Error);
     }
 }
diff --git a/license-generator/src/lib.rs b/license-generator/src/lib.rs
index e129d17..4dd726d 100644
--- a/license-generator/src/lib.rs
+++ b/license-generator/src/lib.rs
@@ -1,10 +1,11 @@
 #[macro_use]
 extern crate error_chain;
+extern crate log;
 extern crate mysql;
 extern crate rand;
 extern crate sha1;
 
 
-mod database;
-mod errors;
+pub mod database;
+pub mod errors;
 mod purchaser;
diff --git a/license-generator/src/main.rs b/license-generator/src/main.rs
index fab9eb1..32fdc3b 100644
--- a/license-generator/src/main.rs
+++ b/license-generator/src/main.rs
@@ -1,8 +1,41 @@
 extern crate fastcgi;
 
+#[macro_use]
+extern crate log;
+extern crate mysql;
+extern crate simplelog;
+
+extern crate license_generator;
+
+use std::env;
+use std::fs::OpenOptions;
 use std::io::{Read, Write};
 
-fn main() {
+use simplelog::{Config, LevelFilter, WriteLogger};
+
+use license_generator::database;
+use license_generator::errors::*;
+
+fn main() -> Result<()> {
+    let log_file_path = env::var("LOG_FILE")?;
+
+    let log_file = OpenOptions::new()
+        .append(true)
+        .create(true)
+        .open(log_file_path)?;
+
+    WriteLogger::init(LevelFilter::Info, Config::default(), log_file)?;
+
+    let cx = match database::get_database_connection()
+        .chain_err(|| "failed to create a database connection")
+    {
+        Ok(cx) => cx,
+        Err(e) => {
+            error!("{}", e);
+            return Err(e);
+        },
+    };
+
     fastcgi::run(|mut req| {
         write!(&mut req.stdout(), "Content-Type: text/plain\n\nHello, world!")
             .unwrap_or(());
@@ -21,4 +54,6 @@ fn main() {
         write!(&mut req.stdout(), "\n\nstdin: {}\n", stdin)
             .unwrap_or(());
     });
+
+    Ok(())
 }