Rebuild SSH installation (#20220)

Closes #ISSUE

This refactors SSH installation to require less shell stuff. We'd like
to
support arbitrary remote hosts, and unfortunately csh/tcsh have quoting
rules
that make it impossible to run multi-line scripts.

The primary changes are:
* The target path now contains the version:
`./zed_server/zed-remote-server-{release_channel}-{version}`
* We do all our processing in a temporary file and `mv` it into place.
* We do fewer calls to `ssh_command` overall. With the previous two
changes we can avoid lock files, and fuser calls. Instead cleanup of old
binaries now happens in `execute_run`.
* We only try to install the remote server when the connection is
established, not on each project open.

This should also put us in a good position if we want to pre-emptively
install new versions when the auto-updater detects an update for the
running version of zed (but that's not wired up yet)

Release Notes:

- Remoting: Fixed remoting when the remote runs `tcsh`
- Remoting: Improved latency of connecting

crates/auto_update/src/auto_update.rs

@@ -432,6 +432,9 @@ impl AutoUpdater {
         cx.notify();
     }
 
+    // If you are packaging Zed and need to override the place it downloads SSH remotes from,
+    // you can override this function. You should also update get_remote_server_release_url to return
+    // Ok(None).
     pub async fn download_remote_server_release(
         os: &str,
         arch: &str,
@@ -482,7 +485,7 @@ impl AutoUpdater {
         release_channel: ReleaseChannel,
         version: Option<SemanticVersion>,
         cx: &mut AsyncAppContext,
-    ) -> Result<(JsonRelease, String)> {
+    ) -> Result<Option<(String, String)>> {
         let this = cx.update(|cx| {
             cx.default_global::<GlobalAutoUpdate>()
                 .0
@@ -504,7 +507,7 @@ impl AutoUpdater {
         let update_request_body = build_remote_server_update_request_body(cx)?;
         let body = serde_json::to_string(&update_request_body)?;
 
-        Ok((release, body))
+        Ok(Some((release.url, body)))
     }
 
     async fn get_release(

crates/recent_projects/src/ssh_connections.rs

@@ -478,43 +478,17 @@ impl remote::SshClientDelegate for SshClientDelegate {
         release_channel: ReleaseChannel,
         version: Option<SemanticVersion>,
         cx: &mut AsyncAppContext,
-    ) -> Task<Result<(String, String)>> {
+    ) -> Task<Result<Option<(String, String)>>> {
         cx.spawn(|mut cx| async move {
-                let (release, request_body) = AutoUpdater::get_remote_server_release_url(
-                            platform.os,
-                            platform.arch,
-                            release_channel,
-                            version,
-                            &mut cx,
-                        )
-                        .await
-                        .map_err(|e| {
-                            anyhow!(
-                                "Failed to get remote server binary download url (version: {}, os: {}, arch: {}): {}",
-                                version.map(|v| format!("{}", v)).unwrap_or("unknown".to_string()),
-                                platform.os,
-                                platform.arch,
-                                e
-                            )
-                        })?;
-
-                Ok((release.url, request_body))
-            }
-        )
-    }
-
-    fn remote_server_binary_path(
-        &self,
-        platform: SshPlatform,
-        cx: &mut AsyncAppContext,
-    ) -> Result<PathBuf> {
-        let release_channel = cx.update(|cx| ReleaseChannel::global(cx))?;
-        Ok(paths::remote_server_dir_relative().join(format!(
-            "zed-remote-server-{}-{}-{}",
-            release_channel.dev_name(),
-            platform.os,
-            platform.arch
-        )))
+            AutoUpdater::get_remote_server_release_url(
+                platform.os,
+                platform.arch,
+                release_channel,
+                version,
+                &mut cx,
+            )
+            .await
+        })
     }
 }
 

crates/remote/Cargo.toml

@@ -26,6 +26,7 @@ futures.workspace = true
 gpui.workspace = true
 itertools.workspace = true
 log.workspace = true
+paths.workspace = true
 parking_lot.workspace = true
 prost.workspace = true
 rpc = { workspace = true, features = ["gpui"] }