refactor: Turn server in a proper command

Turn `server` into proper command, with a `command` function in its own module, its own
error type, etc, in preparation of adding subcommands to it.

src/commands/server.rs

@@ -1,9 +1,12 @@
 //! Implementation of command line option for manipulating and showing server
 //! config
 
+use crate::commands::logging::LoggingLevel;
+use crate::influxdb_ioxd;
 use clap::arg_enum;
 use std::{net::SocketAddr, net::ToSocketAddrs, path::PathBuf};
 use structopt::StructOpt;
+use thiserror::Error;
 
 /// The default bind address for the HTTP API.
 pub const DEFAULT_API_BIND_ADDR: &str = "127.0.0.1:8080";
@@ -15,6 +18,14 @@ pub const DEFAULT_GRPC_BIND_ADDR: &str = "127.0.0.1:8082";
 /// specified.
 pub const FALLBACK_AWS_REGION: &str = "us-east-1";
 
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("Server error")]
+    ServerError(#[from] influxdb_ioxd::Error),
+}
+
+pub type Result<T, E = Error> = std::result::Result<T, E>;
+
 #[derive(Debug, StructOpt)]
 #[structopt(
     name = "server",
@@ -214,6 +225,10 @@ Possible values (case insensitive):
     pub jaeger_host: Option<String>,
 }
 
+pub async fn command(logging_level: LoggingLevel, config: Box<Config>) -> Result<()> {
+    Ok(influxdb_ioxd::main(logging_level, config).await?)
+}
+
 fn parse_socket_addr(s: &str) -> std::io::Result<SocketAddr> {
     let mut addrs = s.to_socket_addrs()?;
     // when name resolution fails, to_socket_address returns a validation error

src/main.rs

@@ -12,7 +12,7 @@ use std::str::FromStr;
 use dotenv::dotenv;
 use structopt::StructOpt;
 use tokio::runtime::Runtime;
-use tracing::{debug, error, warn};
+use tracing::{debug, warn};
 
 use commands::logging::LoggingLevel;
 use ingest::parquet::writer::CompressionLevel;
@@ -187,11 +187,9 @@ fn main() -> Result<(), std::io::Error> {
             Some(Command::Server(config)) => {
                 // Note don't set up basic logging here, different logging rules apply in server
                 // mode
-                let res = influxdb_ioxd::main(logging_level, config).await;
-
-                if let Err(e) = res {
-                    error!("Server shutdown with error: {}", e);
-                    std::process::exit(ReturnCode::Failure as _);
+                if let Err(e) = commands::server::command(logging_level, config).await {
+                    eprintln!("Server command failed: {}", e);
+                    std::process::exit(ReturnCode::Failure as _)
                 }
             }
             None => {