Add support for overriding remote docker images

Previously, only local images could be overridden.

This adds a new env variable DOCSRS_DOCKER_IMAGE, and makes the existing
variable DOCS_RS_LOCAL_DOCKER_IMAGE a synonym for it. At some point I
want to remove the old name, but that requires updating forge first.

Author: jyn514

src/config.rs

@@ -57,7 +57,7 @@ pub struct Config {
     pub(crate) build_attempts: u16,
     pub(crate) rustwide_workspace: PathBuf,
     pub(crate) inside_docker: bool,
-    pub(crate) local_docker_image: Option<String>,
+    pub(crate) docker_image: Option<String>,
     pub(crate) toolchain: String,
     pub(crate) build_cpu_limit: Option<u32>,
     pub(crate) include_default_targets: bool,
@@ -108,7 +108,8 @@ impl Config {
 
             rustwide_workspace: env("CRATESFYI_RUSTWIDE_WORKSPACE", PathBuf::from(".workspace"))?,
             inside_docker: env("DOCS_RS_DOCKER", false)?,
-            local_docker_image: maybe_env("DOCS_RS_LOCAL_DOCKER_IMAGE")?,
+            docker_image: maybe_env("DOCS_RS_LOCAL_DOCKER_IMAGE")?
+                .or(maybe_env("DOCSRS_DOCKER_IMAGE")?),
             toolchain: env("CRATESFYI_TOOLCHAIN", "nightly".to_string())?,
             build_cpu_limit: maybe_env("DOCS_RS_BUILD_CPU_LIMIT")?,
             include_default_targets: env("DOCSRS_INCLUDE_DEFAULT_TARGETS", true)?,

src/docbuilder/rustwide_builder.rs

@@ -15,7 +15,7 @@ use docsrs_metadata::{Metadata, DEFAULT_TARGETS, HOST_TARGET};
 use failure::ResultExt;
 use log::{debug, info, warn, LevelFilter};
 use postgres::Client;
-use rustwide::cmd::{Command, SandboxBuilder, SandboxImage};
+use rustwide::cmd::{Command, CommandError, SandboxBuilder, SandboxImage};
 use rustwide::logging::{self, LogStorage};
 use rustwide::toolchain::ToolchainError;
 use rustwide::{Build, Crate, Toolchain, Workspace, WorkspaceBuilder};
@@ -53,8 +53,13 @@ impl RustwideBuilder {
 
         let mut builder = WorkspaceBuilder::new(&config.rustwide_workspace, USER_AGENT)
             .running_inside_docker(config.inside_docker);
-        if let Some(custom_image) = &config.local_docker_image {
-            builder = builder.sandbox_image(SandboxImage::local(&custom_image)?);
+        if let Some(custom_image) = &config.docker_image {
+            let image = match SandboxImage::local(&custom_image) {
+                Ok(i) => i,
+                Err(CommandError::SandboxImageMissing(_)) => SandboxImage::remote(custom_image)?,
+                Err(err) => return Err(err.into()),
+            };
+            builder = builder.sandbox_image(image);
         }
         if cfg!(test) {
             builder = builder.fast_init(true);