curl command not available in emqx-docker 5.8.4 image for health checks

[zhongwencool]

Hello EMQX Team,

I'm encountering an issue with the emqx/emqx Docker image version 5.8.4. I've been trying to implement a health check mechanism using the curl command to query the /status endpoint, as invoking emqx_ctl each time consumes too much CPU up to 100% peak usage, which is not ideal for health checking.

However, it appears that the curl command is not available within the 5.8.4 Docker image. When attempting to execute a health check via curl, the command is not recognized and fails.

Steps to Reproduce:

docker run -d --name emqx -p 1883:1883 -p 8083:8083 -p 8084:8084 -p 8883:8883 -p 18083:18083 emqx/emqx:5.8.4

docker exec -u root -it emqx /bin/bash
root@f1df45009b01:/opt/emqx# curl
bash: curl: command not found

docker exec -u emqx -it emqx /bin/bash
emqx@f1df45009b01:/opt/emqx$ curl
bash: curl: command not found

Expected Behavior:

The curl command should be able to reach the EMQX status API and return a response indicating the health of the service.

Actual Behavior:

The curl command is not found or does not work within the container environment.

The CI log may contain potential errors or build failures.

https://github.com/emqx/emqx-docker/actions/runs/12638560515/job/35215085251#step:6:111

#9 3.991 debconf: (Can't locate Term/ReadLine.pm in @INC (you may need to install the Term::ReadLine module) (@INC contains: /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.36.0 /usr/local/share/perl/5.36.0 /usr/lib/x86_64-linux-gnu/perl5/5.36 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl-base /usr/lib/x86_64-linux-gnu/perl/5.36 /usr/share/perl/5.36 /usr/local/lib/site_perl) at /usr/share/perl5/Debconf/FrontEnd/Readline.pm line 7.)
#9 3.991 debconf: falling back to frontend: Teletype
#9 4.491 Updating certificates in /etc/ssl/certs...
#9 5.254 140 added, 0 removed; done.
#9 5.272 Setting up libgssapi-krb5-2:amd64 (1.20.1-2+deb12u2) ...
#9 5.276 Setting up libcurl4:amd64 (7.88.1-10+deb12u8) ...
#9 5.279 Setting up curl (7.88.1-10+deb12u8) ...

but not curl command available .
Also:

#9 [linux/amd64 2/4] RUN set -eu;     apt-get update;     apt-get install -y --no-install-recommends ca-certificates procps curl;     arch=$(dpkg --print-architecture);     if [ ${arch} = "amd64" ]; then sha256="48776760e500e0e38b810c9c2e4156ec5022565f700bbea121695e76463ed042"; fi;     if [ ${arch} = "arm64" ]; then sha256="dd45d06ee2f7f5ace05ec9ce53b2739b54dad2105cdfcadb6f7bb514724caf91"; fi;     . /etc/os-release;     pkg="emqx-5.8.4-${ID}${VERSION_ID}-${arch}.tar.gz";     curl -f -O -L [https://www.emqx.com/en/downloads/broker/v5.8.4/${pkg};](https://www.emqx.com/en/downloads/broker/v5.8.4/$%7Bpkg%7D;)     echo "$sha256 *$pkg" | sha256sum -c;     mkdir /opt/emqx;     tar zxf $pkg -C /opt/emqx;     find /opt/emqx -name 'swagger*.js.map' -exec rm {} +;     ln -s /opt/emqx/bin/* /usr/local/bin/;     groupadd -r -g 1000 emqx;     useradd -r -m -u 1000 -g emqx emqx;     chown -R emqx:emqx /opt/emqx;     rm -f $pkg;     rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

#10 [linux/arm64 2/4] RUN set -eu;     apt-get update;     apt-get install -y --no-install-recommends ca-certificates procps curl;     arch=$(dpkg --print-architecture);     if [ ${arch} = "amd64" ]; then sha256="48776760e500e0e38b810c9c2e4156ec5022565f700bbea121695e76463ed042"; fi;     if [ ${arch} = "arm64" ]; then sha256="dd45d06ee2f7f5ace05ec9ce53b2739b54dad2105cdfcadb6f7bb514724caf91"; fi;     . /etc/os-release;     pkg="emqx-5.8.4-${ID}${VERSION_ID}-${arch}.tar.gz";     curl -f -O -L [https://www.emqx.com/en/downloads/broker/v5.8.4/${pkg};](https://www.emqx.com/en/downloads/broker/v5.8.4/$%7Bpkg%7D;)     echo "$sha256 *$pkg" | sha256sum -c;     mkdir /opt/emqx;     tar zxf $pkg -C /opt/emqx;     find /opt/emqx -name 'swagger*.js.map' -exec rm {} +;     ln -s /opt/emqx/bin/* /usr/local/bin/;     groupadd -r -g 1000 emqx;     useradd -r -m -u 1000 -g emqx emqx;     chown -R emqx:emqx /opt/emqx;     rm -f $pkg;     rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

This command run twice.

[zmstone]

please pull emqx:5.8.4 for now. not emqx/emqx:5.8.4.

[id]

@zhongwencool

The curl command is not found or does not work within the container environment.

the curl binary was removed to reduce image size

This command run twice.

no, it's the same command for 2 different builds for different architectures

#9 [linux/amd64 2/4]

#10 [linux/arm64 2/4]

[id]

here is how you can do healtcheck without curl

services:
  emqx:
    image: emqx:latest
    healthcheck:
      test: "bash -c \"exec 3<>/dev/tcp/localhost/18083; echo -e 'GET /api/v5/status HTTP/1.1\r\nhost: localhost\r\nConnection: close\r\n\r\n' >&3; grep -qz 'emqx is running' <&3\""
      interval: 5s
      timeout: 5s
      retries: 5
    container_name: node1.emqx.io
    environment:
      - "EMQX_HOST=node1.emqx.io"