allow users to set Kaleido path via envionment variable

 - introduced a new feature to allow users to download Kaleido at
   compile time when the applications are targeted for the host machine
 - this can be overriden by the runtime environment variable

Signed-off-by: Andrei Gherghescu <[email protected]>

examples/kaleido/Cargo.toml

@@ -1,8 +1,12 @@
 [package]
 name = "kaleido"
 version = "0.1.0"
-authors = ["Michael Freeborn <[email protected]>"]
+authors = [
+    "Michael Freeborn <[email protected]>",
+    "Andrei Gherghescu [email protected]",
+]
 edition = "2021"
 
 [dependencies]
-plotly = { path = "../../plotly", features = ["kaleido"] }
+plotly = { path = "../../plotly", features = ["kaleido", "kaleido_fetch"] }
+# plotly = { path = "../../plotly", features = ["kaleido"] }

plotly/Cargo.toml

@@ -15,10 +15,12 @@ exclude = ["target/*"]
 
 [features]
 kaleido = ["plotly_kaleido"]
+kaleido_fetch = ["plotly_kaleido/download"]
+
 plotly_ndarray = ["ndarray"]
 plotly_image = ["image"]
-# Embed JavaScript into library and templates for offline use
 plotly_embed_js = []
+
 wasm = ["getrandom", "js-sys", "wasm-bindgen", "wasm-bindgen-futures"]
 with-axum = ["rinja/with-axum", "rinja_axum"]
 
@@ -48,6 +50,8 @@ image = "0.25"
 itertools = ">=0.10, <0.14"
 itertools-num = "0.1"
 ndarray = "0.16"
-plotly_kaleido = { version = "0.11", path = "../plotly_kaleido" }
+plotly_kaleido = { version = "0.11", path = "../plotly_kaleido", features = [
+    "download",
+] }
 rand_distr = "0.4"
 base64 = "0.22"

plotly/src/plot.rs

@@ -585,7 +585,7 @@ impl PartialEq for Plot {
 mod tests {
     use std::path::PathBuf;
 
-    use base64::{engine::general_purpose, Engine as _};
+
     use serde_json::{json, to_value};
 
     use super::*;

plotly_kaleido/Cargo.toml

@@ -2,7 +2,10 @@
 name = "plotly_kaleido"
 version = "0.11.0"
 description = "Additional output format support for plotly using Kaleido"
-authors = ["Ioannis Giagkiozis <[email protected]>"]
+authors = [
+    "Ioannis Giagkiozis <[email protected]>",
+    "Andrei Gherghescu [email protected]",
+]
 license = "MIT"
 readme = "README.md"
 workspace = ".."
@@ -14,13 +17,19 @@ keywords = ["plot", "chart", "plotly", "ndarray"]
 
 exclude = ["target/*", "kaleido/*", "examples/*"]
 
+[features]
+download = []
+
 [dependencies]
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 base64 = "0.22"
 dunce = "1.0"
 directories = ">=4, <6"
 
+[dev-dependencies]
+plotly_kaleido = { version = "0.11", path = ".", features = ["download"] }
+
 [build-dependencies]
 zip = "2.1"
 directories = ">=4, <6"

plotly_kaleido/build.rs

@@ -30,15 +30,12 @@ const KALEIDO_URL: &str =
 const KALEIDO_URL: &str =
     "https://github.com/plotly/Kaleido/releases/download/v0.2.1/kaleido_mac_arm64.zip";
 
-#[cfg(target_os = "linux")]
+#[cfg(any(target_os = "linux", target_os = "macos"))]
 const KALEIDO_BIN: &str = "kaleido";
 
 #[cfg(target_os = "windows")]
 const KALEIDO_BIN: &str = "kaleido.exe";
 
-#[cfg(target_os = "macos")]
-const KALEIDO_BIN: &str = "kaleido";
-
 fn extract_zip(p: &Path, zip_file: &Path) -> Result<()> {
     let file = fs::File::open(zip_file).unwrap();
     let mut archive = zip::ZipArchive::new(file).unwrap();
@@ -95,35 +92,56 @@ fn extract_zip(p: &Path, zip_file: &Path) -> Result<()> {
 }
 
 fn main() -> Result<()> {
-    let project_dirs = ProjectDirs::from("org", "plotly", "kaleido")
-        .expect("Could not create plotly_kaleido config directory.");
-    let dst: PathBuf = project_dirs.config_dir().into();
+    if cfg!(feature = "download") {
+        let project_dirs = ProjectDirs::from("org", "plotly", "kaleido")
+            .expect("Could not create Kaleido config directory path.");
+        let dst: PathBuf = project_dirs.config_dir().into();
+
+        let kaleido_binary = dst.join("bin").join(KALEIDO_BIN);
+
+        println!("cargo:rerun-if-changed=src/lib.rs");
+        println!(
+            "cargo::rerun-if-changed={}",
+            kaleido_binary.to_string_lossy()
+        );
+
+        println!(
+            "cargo:rustc-env=KALEIDO_COMPILE_TIME_DLD_PATH={}",
+            dst.to_string_lossy()
+        );
+
+        if kaleido_binary.exists() {
+            return Ok(());
+        }
 
-    let kaleido_binary = dst.join("bin").join(KALEIDO_BIN);
-    if kaleido_binary.exists() {
-        return Ok(());
+        let msg = format!(
+            "Downloaded Plotly Kaleido from {KALEIDO_URL} to '{}'",
+            dst.to_string_lossy()
+        );
+        println!("cargo::warning={msg}");
+
+        let p = PathBuf::from(env::var("OUT_DIR").unwrap());
+        let kaleido_zip_file = p.join("kaleido.zip");
+
+        let mut cmd = Command::new("cargo")
+            .args(["install", "ruget"])
+            .spawn()
+            .unwrap();
+        cmd.wait()?;
+
+        let mut cmd = Command::new("ruget")
+            .args([
+                KALEIDO_URL,
+                "-o",
+                kaleido_zip_file.as_path().to_str().unwrap(),
+            ])
+            .spawn()
+            .unwrap();
+        cmd.wait()?;
+
+        extract_zip(&dst, &kaleido_zip_file)?;
+    } else {
+        println!("'download' feature disabled. Kaleido binary won't be downloaded and must be installed manually.")
     }
-
-    let p = PathBuf::from(env::var("OUT_DIR").unwrap());
-    let kaleido_zip_file = p.join("kaleido.zip");
-
-    let mut cmd = Command::new("cargo")
-        .args(["install", "ruget"])
-        .spawn()
-        .unwrap();
-    cmd.wait()?;
-
-    let mut cmd = Command::new("ruget")
-        .args([
-            KALEIDO_URL,
-            "-o",
-            kaleido_zip_file.as_path().to_str().unwrap(),
-        ])
-        .spawn()
-        .unwrap();
-    cmd.wait()?;
-
-    extract_zip(&dst, &kaleido_zip_file)?;
-    println!("cargo:rerun-if-changed=src/lib.rs");
     Ok(())
 }

plotly_kaleido/src/lib.rs

@@ -17,7 +17,6 @@ use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
 
 use base64::{engine::general_purpose, Engine as _};
-use directories::ProjectDirs;
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 
@@ -77,49 +76,59 @@ pub struct Kaleido {
 }
 
 impl Kaleido {
+    const KALEIDO_PATH_ENV: &str = "KALEIDO_PATH";
+
     pub fn new() -> Kaleido {
-        let path = match Kaleido::binary_path() {
-            Ok(path) => path,
-            Err(msg) => panic!("{}", msg),
+        use std::env;
+
+        let path = match env::var(Self::KALEIDO_PATH_ENV) {
+            Ok(runtime_env) => runtime_env,
+            Err(runtime_env_err) => match option_env!("KALEIDO_COMPILE_TIME_DLD_PATH") {
+                Some(compile_time_path) => compile_time_path.to_string(),
+                None => {
+                    println!("{}: {}", Self::KALEIDO_PATH_ENV, runtime_env_err);
+                    println!("Use `kaleido_fetch` feature to automatically download, install and use Kaleido when targeting applications that run on the host machine.");
+                    println!("Use `{}` environment variable when targeting applications intended to run on different machines. Manually install Kaleido on the target machine and point {} to the installation location.", Self::KALEIDO_PATH_ENV, Self::KALEIDO_PATH_ENV
+                    );
+                    std::process::exit(1);
+                }
+            },
         };
 
-        Kaleido { cmd_path: path }
-    }
+        let path = match Kaleido::binary_path(&path) {
+            Ok(kaleido_path) => kaleido_path,
+            Err(msg) => panic!("Failed tu use Kaleido binary at {} due to {}", path, msg),
+        };
 
-    fn root_dir() -> Result<PathBuf, &'static str> {
-        let project_dirs = ProjectDirs::from("org", "plotly", "kaleido")
-            .expect("Could not create plotly_kaleido config directory.");
-        Ok(project_dirs.config_dir().into())
+        Kaleido { cmd_path: path }
     }
 
-    #[cfg(target_os = "linux")]
-    fn binary_path() -> Result<PathBuf, &'static str> {
-        let mut p = Kaleido::root_dir()?;
-        p = p.join("kaleido").canonicalize().unwrap();
+    fn binary_path(dld_path: &str) -> Result<PathBuf, &'static str> {
+        let mut p = PathBuf::from(dld_path);
+        p = Self::os_binary_path(p);
         if !p.exists() {
             return Err("could not find kaleido executable in path");
         }
         Ok(p)
     }
 
-    #[cfg(target_os = "macos")]
-    fn binary_path() -> Result<PathBuf, &'static str> {
-        let mut p = Kaleido::root_dir()?;
-        p = p.join("kaleido").canonicalize().unwrap();
-        if !p.exists() {
-            return Err("could not find kaleido executable in path");
+    #[cfg(any(target_os = "linux", target_os = "macos"))]
+    fn os_binary_path(path: PathBuf) -> PathBuf {
+        match path.join("kaleido").canonicalize() {
+            Ok(v) => v,
+            Err(e) => {
+                println!(
+                    "Failed to find Kaleido binary at '{}': {e}",
+                    path.to_string_lossy()
+                );
+                panic!("{e}");
+            }
         }
-        Ok(p)
     }
 
     #[cfg(target_os = "windows")]
-    fn binary_path() -> Result<PathBuf, &'static str> {
-        let mut p = Kaleido::root_dir()?;
-        p = p.join("kaleido.cmd");
-        if !p.exists() {
-            return Err("could not find kaleido executable in path");
-        }
-        Ok(p)
+    fn os_binary_path(path: PathBuf) -> PathBuf {
+        p.join("kaleido.cmd")
     }
 
     /// Generate a static image from a Plotly graph and save it to a file
@@ -193,7 +202,16 @@ impl Kaleido {
             .stdout(Stdio::piped())
             .stderr(Stdio::piped())
             .spawn()
-            .expect("failed to spawn Kaleido binary");
+            .unwrap_or_else(|_| {
+                panic!(
+                    "{}",
+                    format!(
+                        "failed to spawn Kaleido binary at {}",
+                        self.cmd_path.to_string_lossy()
+                    )
+                    .to_string()
+                )
+            });
 
         {
             let plot_data = PlotData::new(plotly_data, format, width, height, scale).to_json();