add proxmox-backup-banner binary crate

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

src/bin/proxmox-backup-banner.rs

@@ -1,49 +0,0 @@
-use std::fmt::Write;
-use std::fs;
-use std::net::ToSocketAddrs;
-
-use proxmox::tools;
-
-fn main() {
-    let nodename = tools::nodename();
-    let addr = format!("{}:8007", nodename);
-
-    let mut banner = format!(
-        "
-{:-<78}
-
-Welcome to the Proxmox Backup Server. Please use your web browser to
-configure this server - connect to:
-
-",
-        ""
-    );
-
-    let msg = match addr.to_socket_addrs() {
-        Ok(saddrs) => {
-            let saddrs: Vec<_> = saddrs
-                .filter_map(|s| match !s.ip().is_loopback() {
-                    true => Some(format!(" https://{}/", s)),
-                    false => None,
-                })
-                .collect();
-
-            if !saddrs.is_empty() {
-                saddrs.join("\n")
-            } else {
-                format!(
-                    "hostname '{}' does not resolves to any non-loopback address",
-                    nodename
-                )
-            }
-        }
-        Err(e) => format!("could not resolve hostname '{}': {}", nodename, e),
-    };
-    banner += &msg;
-
-    // unwrap will never fail for write!:
-    // https://github.com/rust-lang/rust/blob/1.39.0/src/liballoc/string.rs#L2318-L2331
-    write!(&mut banner, "\n\n{:-<78}\n\n", "").unwrap();
-
-    fs::write("/etc/issue", banner.as_bytes()).expect("Unable to write banner to issue file");
-}