Rust in Docker image: exec no such file or directory

Question

I try to create a Docker image with a small Rust application. I want to run it on my Kubernetes cluster running on Raspberry Pi 4b. So the image must be linux/arm64/v8.

I create the image with this command on macOS:

$ docker build --platform linux/arm64/v8 -t dasralph/ping:arm64_1.0.4 .

But when I run it on a Raspberry Pi, the exec isn't found:

$ sudo docker run dasralph/ping:arm64_1.0.4
Unable to find image 'dasralph/ping:arm64_1.0.4' locally
arm64_1.0.4: Pulling from dasralph/ping
4f4fb700ef54: Pull complete
38f252ce47e1: Pull complete
Digest: sha256:4fbda499e0552bf08bf230db56906d185bd340655c0cc741ad10ee0ea642c626
Status: Downloaded newer image for dasralph/ping:arm64_1.0.4
exec /ping: no such file or directory

This is my Docker file:

# STAGE 1 is to build the binary
# Use rust-based image for container
FROM rust:1.61 AS builder

# Adding necessary packages
RUN apt update && apt upgrade -y
RUN apt install -y g++-aarch64-linux-gnu libc6-dev-arm64-cross

RUN rustup target add aarch64-unknown-linux-gnu
RUN rustup toolchain install stable-aarch64-unknown-linux-gnu

ENV CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER=aarch64-linux-gnu-gcc \
    CC_aarch64_unknown_linux_gnu=aarch64-linux-gnu-gcc \
    CXX_aarch64_unknown_linux_gnu=aarch64-linux-gnu-g++


# Set working directory in container; make directory if not exists
RUN mkdir -p /usr/src/ping
WORKDIR /usr/src/ping

# Copy all Cargo files from local computer to container
COPY Cargo.toml .
COPY Cargo.lock .
COPY .env.docker .env
COPY src src

# Build release application
RUN cargo build --target aarch64-unknown-linux-gnu --release


# STAGE 2 is to have smallest image possible by including only necessary binary
# Use smallest base image
FROM shinsenter/scratch

# Copy application binary from STAGE 1 image to STAGE 2 image
COPY --from=builder /usr/src/ping/target/aarch64-unknown-linux-gnu/release/ping /

EXPOSE 8080

ENTRYPOINT ["/ping"]

Has anyone a hint of what's going wrong?

Cargo.toml

[package]
name = "ping"
version = "0.2.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
actix-web = "4"
load-dotenv = "0.1.2"

main.rs

use actix_web::{get, App, HttpResponse, HttpServer, Responder};
use std::env;

use load_dotenv::load_dotenv;

load_dotenv!();

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    let bind_address = env!("BIND_ADDRESS", "BIND_ADDRESS must be set");
    println!("BIND_ADDRESS: {bind_address}");

    HttpServer::new(|| {
        App::new()
            .service(hello)
    })
        .bind((bind_address, 8080))?
        .run()
        .await
}

#[get("/")]
async fn hello() -> impl Responder {
    HttpResponse::Ok().body("Hello Ralph!")
}

Answer 1

My problem was, that I need to make sure that Rust compiles into a static binary. It looks like MUSL is one way to do that.

This is now my updated Dockerfile:

# Build: docker build --platform linux/arm64/v8 -t dasralph/ping:arm64_0.1.0 --push .
# Run: docker run -p 8080:8080 ping
# Test: curl http://localhost:8080/

# STAGE 1 is to build the binary
# Use rust-based image for container
FROM rust:1.61.0-alpine AS builder

# Adding necessary packages
RUN apk update
RUN apk add pkgconfig openssl openssl-dev musl-dev

RUN rustup target add aarch64-unknown-linux-musl
RUN rustup toolchain install stable-aarch64-unknown-linux-musl

# Set working directory in container; make directory if not exists
RUN mkdir -p /usr/src/ping
WORKDIR /usr/src/ping

# Copy all files from local computer to container
COPY Cargo.toml .
COPY Cargo.lock .
COPY .env.docker .env
COPY src src

# Build release application
RUN cargo build --target aarch64-unknown-linux-musl --release


# STAGE 2 is to have smallest image possible by including only necessary binary
# Use smallest base image
FROM shinsenter/scratch

# Copy application binary from STAGE 1 image to STAGE 2 image
COPY --from=builder /usr/src/ping/target/aarch64-unknown-linux-musl/release/ping /

EXPOSE 8080

ENTRYPOINT ["/ping"]