docker: switch to a 2-stage build and provide an Alpine-based alternative

.github/workflows/docker-push-image.yml

@@ -28,11 +28,22 @@ jobs:
         username: ${{ github.repository_owner }}
         password: ${{ secrets.GITHUB_TOKEN }}
 
-    - name: Build and push Docker image
+    - name: Build and push Debian image
       uses: docker/build-push-action@v7
       with:
         context: ./docker/
+        file: ./docker/Dockerfile
         push: true
         tags: |
           opensips/opensips-cli:latest
           ghcr.io/opensips/opensips-cli:latest
+
+    - name: Build and push Alpine image
+      uses: docker/build-push-action@v7
+      with:
+        context: ./docker/
+        file: ./docker/Dockerfile.alpine
+        push: true
+        tags: |
+          opensips/opensips-cli:alpine
+          ghcr.io/opensips/opensips-cli:alpine

docker/Dockerfile

@@ -1,27 +1,20 @@
-FROM python:slim-trixie
-LABEL maintainer="Razvan Crainea <razvan@opensips.org>"
-
-USER root
+ARG BASE_IMAGE=python:slim-trixie
 
-# Set Environment Variables
-ENV DEBIAN_FRONTEND noninteractive
+FROM ${BASE_IMAGE} AS builder
 
-#install basic components
 RUN apt-get -y update -qq && \
-    apt-get -y install git
+    apt-get -y --no-install-recommends install git && \
+    git clone https://github.com/OpenSIPS/opensips-cli.git /usr/src/opensips-cli && \
+    python3 -m pip install --no-cache-dir /usr/src/opensips-cli
 
-#add keyserver, repository
-RUN git clone https://github.com/OpenSIPS/opensips-cli.git /usr/src/opensips-cli && \
-    cd /usr/src/opensips-cli && \
-    python3 -m pip install . && \
-    cd / && rm -rf /usr/src/opensips-cli
+FROM ${BASE_IMAGE}
+LABEL maintainer="Razvan Crainea <razvan@opensips.org>"
 
-RUN apt-get purge -y git && \
-    apt-get autoremove -y && \
-    apt-get clean
+COPY --from=builder /usr/local/lib /usr/local/lib
+COPY --from=builder /usr/local/bin/opensips-cli /usr/local/bin/opensips-cli
 
-ADD "run.sh" "/run.sh"
+RUN python3 -m compileall -q /usr/local/lib
 
-ENV PYTHONPATH /usr/lib/python3/dist-packages
+COPY run.sh /run.sh
 
-ENTRYPOINT ["/run.sh", "-o", "communication_type=http"]
+ENTRYPOINT [ "/run.sh", "-o", "communication_type=http" ]

docker/Dockerfile.alpine

@@ -0,0 +1,19 @@
+ARG BASE_IMAGE=python:alpine
+
+FROM ${BASE_IMAGE} AS builder
+
+RUN apk add --no-cache git && \
+    git clone https://github.com/OpenSIPS/opensips-cli.git /usr/src/opensips-cli && \
+    python3 -m pip install --no-cache-dir /usr/src/opensips-cli
+
+FROM ${BASE_IMAGE}
+LABEL maintainer="Razvan Crainea <razvan@opensips.org>"
+
+COPY --from=builder /usr/local/lib /usr/local/lib
+COPY --from=builder /usr/local/bin/opensips-cli /usr/local/bin/opensips-cli
+
+RUN python3 -m compileall -q /usr/local/lib
+
+COPY run.sh /run.sh
+
+ENTRYPOINT [ "/run.sh", "-o", "communication_type=http" ]

docker/Makefile

@@ -3,11 +3,18 @@ OPENSIPS_DOCKER_TAG ?= latest
 
 all: build start
 
-.PHONY: build start
-build:
-	docker build \
+.PHONY: build build-debian build-alpine start
+build-debian:
+	docker build -f Dockerfile \
 		--tag="opensips/opensips-cli:$(OPENSIPS_DOCKER_TAG)" \
 		.
 
+build: build-debian
+
+build-alpine:
+	docker build -f Dockerfile.alpine \
+		--tag="opensips/opensips-cli:alpine-$(OPENSIPS_DOCKER_TAG)" \
+		.
+
 start:
 	docker run -d --name $(NAME) opensips/opensips-cli:$(OPENSIPS_DOCKER_TAG)

docker/docker.md

@@ -4,13 +4,19 @@ Docker recipe for running [OpenSIPS Command Line
 Interface](https://github.com/OpenSIPS/opensips-cli).
 
 ## Building the image
-You can build the docker image by running:
+You can build the Debian-based docker image by running:
 ```
-make build
+make build-debian
 ```
 
-This command will build a docker image with OpenSIPS CLI master version taken from
-the git repository
+Or the Alpine-based image (smaller footprint) with:
+```
+make build-alpine
+```
+
+`make build` is an alias for `make build-debian`.
+
+All variants install OpenSIPS CLI from the latest master branch on GitHub.
 
 ## Parameters
 
@@ -25,13 +31,20 @@ Meaning of the parameters is as it follows:
 will end up in opensips-cli config file, in the `default` section, as
 `KEY: VALUE` lines
 * `CMD` - the command used to run; if the `CMD` ends with `.sh` extension, it
-will be run as a bash script, if the `CMD` ends with `.py` extension, it is
-run as a python script, otherwise it is run as a `opensips-cli` command
+will be run as a POSIX shell (`sh`) script, if the `CMD` ends with `.py`
+extension, it is run as a python script, otherwise it is run as a
+`opensips-cli` command
 * `PARAMS` - optional additional parameters passed to `CMD`
 
 ## Run
 
-To run a bash script, simply pass the connector followed by the bash script:
+The entrypoint script (`run.sh`) is POSIX `sh`-compatible and requires no
+additional shell. As a result, the Alpine image ships no extra packages beyond
+the base Python Alpine image. Shell scripts passed as `CMD` must also be POSIX
+`sh`-compatible, or include their own `#!/bin/bash` shebang with bash installed
+separately.
+
+To run a shell script, simply pass the connector followed by the script:
 ```
 docker run -d --name opensips-cli opensips/opensips-cli:latest \
 		   -o url=http://8.8.8.8:8888/mi script.sh

docker/run.sh

@@ -1,18 +1,17 @@
-#!/bin/bash
+#!/bin/sh
 
-OPTS=
 CMD=
 PARAMS=
 CFG=/etc/opensips-cli.cfg
 
 echo "[default]" > "$CFG"
 
-while [[ $# -gt 0 ]]; do
+while [ $# -gt 0 ]; do
 	case "$1" in
 	-o|--option)
 		shift
-		P=$(cut -d'=' -f1 <<<"$1")
-		V=$(cut -d'=' -f2- <<<"$1")
+		P=$(echo "$1" | cut -d'=' -f1)
+		V=$(echo "$1" | cut -d'=' -f2-)
 		echo "$P: $V" >> "$CFG"
 		;;
 	*)
@@ -26,12 +25,10 @@ while [[ $# -gt 0 ]]; do
 	shift
 done
 
-if [[ $CMD == *.py ]]; then
-	TOOL=python3
-elif [[ $CMD == *.sh ]]; then
-	TOOL=bash
-else
-	TOOL=opensips-cli
-fi
+case "$CMD" in
+*.py) TOOL=python3 ;;
+*.sh) TOOL=sh ;;
+*)    TOOL=opensips-cli ;;
+esac
 
 exec $TOOL $CMD $PARAMS