How do you set the template_dir while in an containor

[RAPrograms]

I am trying to run a rocket instance within a docker containor. I have a build script which clones all the files in /static to /target/release/static.

The error

app-1  | Error: Invalid template directory 'templates': No such file or directory (os error 2).
app-1  |    >> Template initialization failed. Aborting launch.
app-1  | Error: Rocket failed to launch due to failing fairings:
app-1  |    >> Templating
app-1  | thread 'main' panicked at /usr/local/cargo/registry/src/index.crates.io-6f17d22bba15001f/rocket-0.5.0/src/error.rs:279:9:
app-1  | aborting due to fairing failure(s)
app-1  | note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
app-1 exited with code 101

This is my rocket.toml

[debug]
template_dir = "static/templates"

[release]
template_dir = "static/templates"

My target file structure

.
│   ├── .fingerprint
│   ├── build
│   ├── deps
│   ├── examples
│   ├── incremental
│   ├── static
│   │   └── templates
│   ├── .cargo-lock
│   ├── app
│   └── app.d
├── .rustc_info.json
└── CACHEDIR.TAG

My dockerfile

FROM rust:1.70.0 AS build
ENV ROCKET_ADDRESS=0.0.0.0
ENV ROCKET_PORT=80
WORKDIR /app
COPY . .
RUN rustup default nightly
RUN cargo build --release
EXPOSE 80
CMD ["./target/release/app" ]

[SergioBenitez]

Please see containerization section of the in-progress deployment guide and the guide in general.

[RAPrograms]

Thank you for that link. However, I am encountering a diffrent error

dockerfile (updated)

FROM docker.io/rust:1-slim-bookworm AS build

## cargo package name: customize here or provide via --build-arg
ARG pkg=app

WORKDIR /build

COPY . .

RUN --mount=type=cache,target=/build/target \
    --mount=type=cache,target=/usr/local/cargo/registry \
    --mount=type=cache,target=/usr/local/cargo/git \
    set -eux; \
    cargo build --release; \
    objcopy --compress-debug-sections target/release/$pkg ./main

################################################################################

FROM docker.io/debian:bookworm-slim

WORKDIR /app

## copy the main binary
COPY --from=build /build/main ./

## copy runtime assets which may or may not exist
COPY --from=build /build/Rocket.tom[l] ./static
COPY --from=build /build/stati[c] ./static
COPY --from=build /build/template[s] ./templates

## ensure the container listens globally on port 8080
ENV ROCKET_ADDRESS=0.0.0.0
ENV ROCKET_PORT=8080

CMD ./main

Error

 => [app build 3/4] COPY . .                                                                                                                                     6.1s
 => ERROR [app build 4/4] RUN --mount=type=cache,target=/build/target     --mount=type=cache,target=/usr/local/cargo/registry     --mount=type=cache,target=/us  4.2s
------                                                                                                                                                                
 > [app build 4/4] RUN --mount=type=cache,target=/build/target     --mount=type=cache,target=/usr/local/cargo/registry     --mount=type=cache,target=/usr/local/cargo/git     set -eux;     cargo build --release;     objcopy --compress-debug-sections target/release/app ./main:                                     
0.149 + cargo build --release                                                                                                                                         
0.451    Compiling serde_derive v1.0.201                                                                                                                              
0.451    Compiling tokio-macros v2.2.0                                                                                                                                
0.451    Compiling thiserror-impl v1.0.59
0.451    Compiling futures-macro v0.3.30
0.457    Compiling openssl-sys v0.9.102
0.457    Compiling proc-macro2-diagnostics v0.10.1
0.457    Compiling rustix v0.38.32
0.460    Compiling idna v0.5.0
0.460    Compiling httparse v1.8.0
0.461    Compiling event-listener v4.0.3
0.475 error: failed to run custom build command for `openssl-sys v0.9.102`
0.475 
0.475 Caused by:
0.475   process didn't exit successfully: `/build/target/release/build/openssl-sys-07a49b7c0ec3716f/build-script-main` (exit status: 101)
0.475   --- stdout
0.475   cargo:rerun-if-env-changed=AARCH64_UNKNOWN_LINUX_GNU_OPENSSL_LIB_DIR
0.475   AARCH64_UNKNOWN_LINUX_GNU_OPENSSL_LIB_DIR unset
0.475   cargo:rerun-if-env-changed=OPENSSL_LIB_DIR
0.475   OPENSSL_LIB_DIR unset
0.475   cargo:rerun-if-env-changed=AARCH64_UNKNOWN_LINUX_GNU_OPENSSL_INCLUDE_DIR
0.475   AARCH64_UNKNOWN_LINUX_GNU_OPENSSL_INCLUDE_DIR unset
0.475   cargo:rerun-if-env-changed=OPENSSL_INCLUDE_DIR
0.475   OPENSSL_INCLUDE_DIR unset
0.475   cargo:rerun-if-env-changed=AARCH64_UNKNOWN_LINUX_GNU_OPENSSL_DIR
0.475   AARCH64_UNKNOWN_LINUX_GNU_OPENSSL_DIR unset
0.475   cargo:rerun-if-env-changed=OPENSSL_DIR
0.475   OPENSSL_DIR unset
0.475   cargo:rerun-if-env-changed=OPENSSL_NO_PKG_CONFIG
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_aarch64-unknown-linux-gnu
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_aarch64_unknown_linux_gnu
0.475   cargo:rerun-if-env-changed=HOST_PKG_CONFIG
0.475   cargo:rerun-if-env-changed=PKG_CONFIG
0.475   cargo:rerun-if-env-changed=OPENSSL_STATIC
0.475   cargo:rerun-if-env-changed=OPENSSL_DYNAMIC
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_ALL_STATIC
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_ALL_DYNAMIC
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_PATH_aarch64-unknown-linux-gnu
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_PATH_aarch64_unknown_linux_gnu
0.475   cargo:rerun-if-env-changed=HOST_PKG_CONFIG_PATH
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_PATH
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR_aarch64-unknown-linux-gnu
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR_aarch64_unknown_linux_gnu
0.475   cargo:rerun-if-env-changed=HOST_PKG_CONFIG_LIBDIR
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR_aarch64-unknown-linux-gnu
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR_aarch64_unknown_linux_gnu
0.475   cargo:rerun-if-env-changed=HOST_PKG_CONFIG_SYSROOT_DIR
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR
0.475   cargo:rerun-if-env-changed=OPENSSL_STATIC
0.475   cargo:rerun-if-env-changed=OPENSSL_DYNAMIC
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_ALL_STATIC
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_ALL_DYNAMIC
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_PATH_aarch64-unknown-linux-gnu
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_PATH_aarch64_unknown_linux_gnu
0.475   cargo:rerun-if-env-changed=HOST_PKG_CONFIG_PATH
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_PATH
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR_aarch64-unknown-linux-gnu
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR_aarch64_unknown_linux_gnu
0.475   cargo:rerun-if-env-changed=HOST_PKG_CONFIG_LIBDIR
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR_aarch64-unknown-linux-gnu
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR_aarch64_unknown_linux_gnu
0.475   cargo:rerun-if-env-changed=HOST_PKG_CONFIG_SYSROOT_DIR
0.475   cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR
0.475   run pkg_config fail: Could not run `PKG_CONFIG_ALLOW_SYSTEM_CFLAGS=1 pkg-config --libs --cflags openssl`
0.475   The pkg-config command could not be found.
0.475 
0.475   Most likely, you need to install a pkg-config package for your OS.
0.475   Try `apt install pkg-config`, or `yum install pkg-config`,
0.475   or `pkg install pkg-config`, or `apk add pkgconfig` depending on your distribution.
0.475 
0.475   If you've already installed it, ensure the pkg-config command is one of the
0.475   directories in the PATH environment variable.
0.475 
0.475   If you did not expect this build to link to a pre-installed system library,
0.475   then check documentation of the openssl-sys crate for an option to
0.475   build the library from source, or disable features or dependencies
0.475   that require pkg-config.
0.475 
0.475   --- stderr
0.475   thread 'main' panicked at /usr/local/cargo/registry/src/index.crates.io-6f17d22bba15001f/openssl-sys-0.9.102/build/find_normal.rs:190:5:
0.475 
0.475 
0.475   Could not find directory of OpenSSL installation, and this `-sys` crate cannot
0.475   proceed without this knowledge. If OpenSSL is installed and this crate had
0.475   trouble finding it,  you can set the `OPENSSL_DIR` environment variable for the
0.475   compilation process.
0.475 
0.475   Make sure you also have the development packages of openssl installed.
0.475   For example, `libssl-dev` on Ubuntu or `openssl-devel` on Fedora.
0.475 
0.475   If you're in a situation where you think the directory *should* be found
0.475   automatically, please open a bug at https://github.com/sfackler/rust-openssl
0.475   and include information about your system as well as this message.
0.475 
0.475   $HOST = aarch64-unknown-linux-gnu
0.475   $TARGET = aarch64-unknown-linux-gnu
0.475   openssl-sys = 0.9.102
0.475 
0.475 
0.475   It looks like you're compiling on Linux and also targeting Linux. Currently this
0.475   requires the `pkg-config` utility to find OpenSSL but unfortunately `pkg-config`
0.475   could not be found. If you have OpenSSL installed you can likely fix this by
0.475   installing `pkg-config`.
0.475 
0.475 
0.475   note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
0.475 warning: build failed, waiting for other jobs to finish...
------
failed to solve: process "/bin/sh -c set -eux;     cargo build --release;     objcopy --compress-debug-sections target/release/app ./main" did not complete successfully: exit code: 101

[SergioBenitez]

As you can see in your error, it's failing to build because you're depending on openssl, directly or transitively. As a result, you need to install OpenSSL in the image. You need to add something like the following to your Dockerfile:

RUN set -eux; \
    export DEBIAN_FRONTEND=noninteractive; \
    apt-get update; \
    apt-get install -y --no-install-recommends openssl

Note that this is completely outside the scope of Rocket; Rocket neither directly nor indirectly depends no openssl. Further questions on Dockerfiles should likely be posted at a more appropriate venue.