feat: add dockerfile (#8)

* Define 'release' profile
* Dockerfile to build `tera-cli` image
* Document how to build `tera cli` container
* Update markdown README file

Author: tandiljuan

.dockerignore

@@ -0,0 +1,5 @@
+# Ignore everything
+*
+# With the exception of
+!src/**
+!Cargo*

Cargo.toml

@@ -37,3 +37,9 @@ license-file = ["LICENSE", "0"]
 maintainer = "Wilfried Kopp aka. Chevdor <chevdor@gmail.com>"
 priority = "optional"
 section = "utility"
+
+[profile.release]
+codegen-units = 1
+lto = true
+opt-level = "z"
+panic = "abort"

Dockerfile

@@ -0,0 +1,50 @@
+FROM rust:1.54.0-slim-buster as builder
+
+ARG DEBIAN_FRONTEND=noninteractive
+
+# ******************************************************************************
+# Install dependencies
+# ******************************************************************************
+RUN set -eux \
+    && apt-get update \
+    && apt-get install --no-install-recommends --no-install-suggests --yes \
+        upx-ucl \
+    && apt-get autoremove --purge \
+    && apt-get autoclean \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/* \
+    && echo ">>> FINISHED DEPENDENCIES INSTALL"
+
+# ******************************************************************************
+# Copy source code into container
+# ******************************************************************************
+COPY . /opt/
+
+# ******************************************************************************
+# Compile tera cli application from source
+# ******************************************************************************
+RUN set -eux \
+    && cd /opt/ \
+    && rustup target add x86_64-unknown-linux-musl \
+    && cargo build --release --target x86_64-unknown-linux-musl \
+    && upx --best --lzma target/x86_64-unknown-linux-musl/release/tera \
+    && mv target/x86_64-unknown-linux-musl/release/tera /usr/bin/ \
+    && tera --version \
+    && rm -rf target \
+    && echo ">>> FINISHED COMPILING 'tera-cli'"
+
+# ------------------------------------------------------------------------------
+# ------------------------------------------------------------------------------
+
+FROM alpine
+
+# ******************************************************************************
+# Install compiled tera cli
+# ******************************************************************************
+COPY --from=builder /usr/bin/tera /usr/bin/tera
+
+USER guest
+
+WORKDIR /opt
+
+ENTRYPOINT ["/usr/bin/tera"]

README.md

@@ -75,6 +75,25 @@ The **tera** engine allows way more than the simple replacements shown above. Yo
 
     cargo install --git https://github.com/chevdor/tera-cli
 
+## Execute as Docker container
+
+### Build container image
+
+    docker build --tag 'tera-cli' .
+
+### Execute `tera` from the Docker container
+
+Check tera help
+
+    docker run -it --rm tera-cli --help
+
+Parse a template
+
+    docker run -it --rm \
+        --volume="$(pwd):/opt" \
+        --env=FOO=BAR \
+        tera-cli --template templates/env-debug.txt --env-only --env-key env
+
 ## What can I do with that anyway ?
 
 Well…​ if you have **data** and you want to format them, this tool will likely be a great companion.

README_src.adoc

@@ -56,6 +56,25 @@ The **tera** engine allows way more than the simple replacements shown above. Yo
 
     cargo install --git https://github.com/chevdor/tera-cli
 
+== Execute as Docker container
+
+=== Build container image
+
+    docker build --tag 'tera-cli' .
+
+=== Execute `tera` from the Docker container
+
+Check tera help
+
+    docker run -it --rm tera-cli --help
+
+Parse a template
+
+    docker run -it --rm \
+        --volume="$(pwd):/opt" \
+        --env=FOO=BAR \
+        tera-cli --template templates/env-debug.txt --env-only --env-key env
+
 == What can I do with that anyway ?
 
 Well... if you have **data** and you want to format them, this tool will likely be a great companion.