Add support for pre-build hooks with remote docker.

.changes/934.json

@@ -0,0 +1,5 @@
+{
+    "type": "added",
+    "description": "add support for pre-build hooks with remote docker",
+    "issues": [928]
+}

src/docker/remote.rs

@@ -943,7 +943,14 @@ pub(crate) fn run(
         docker.arg("-t");
     }
 
-    docker.arg(&image_name(&options.config, target)?);
+    let mut image = options.image_name()?;
+    if options.needs_custom_image() {
+        image = options
+            .custom_image_build(&paths, msg_info)
+            .wrap_err("when building custom image")?;
+    }
+
+    docker.arg(&image);
     if !is_tty {
         // ensure the process never exits until we stop it
         // we only need this infinite loop if we don't allocate

src/docker/shared.rs

@@ -74,7 +74,7 @@ impl DockerOptions {
         paths: &DockerPaths,
         msg_info: &mut MessageInfo,
     ) -> Result<String> {
-        let mut image = image_name(&self.config, &self.target)?;
+        let mut image = self.image_name()?;
 
         if let Some(path) = self.config.dockerfile(&self.target)? {
             let context = self.config.dockerfile_context(&self.target)?;
@@ -167,28 +167,7 @@ impl DockerOptions {
     }
 
     pub(crate) fn image_name(&self) -> Result<String> {
-        if let Some(image) = self.config.image(&self.target)? {
-            return Ok(image);
-        }
-
-        if !DOCKER_IMAGES.contains(&self.target.triple()) {
-            eyre::bail!(
-                "`cross` does not provide a Docker image for target {target}, \
-                   specify a custom image in `Cross.toml`.",
-                target = self.target
-            );
-        }
-
-        let version = if include_str!(concat!(env!("OUT_DIR"), "/commit-info.txt")).is_empty() {
-            env!("CARGO_PKG_VERSION")
-        } else {
-            "main"
-        };
-
-        Ok(format!(
-            "{CROSS_IMAGE}/{target}:{version}",
-            target = self.target
-        ))
+        image_name(&self.config, &self.target)
     }
 }