is_ready
is a self-contained program designed to wait until multiple addresses become
accessible. Its purpose is to coordinate the startup of interconnected services, such as
Docker containers that rely on one another. This tool does not rely on any external
dependencies and can be executed as a standalone binary.
There are alternative solutions like
wait-for-it
and wait-for
. The key differentiating factor of is_ready
compared to
alternative solutions is its ability to wait for the availability of multiple addresses,
not only one. Finally, unlike other options, is_ready
stands out as a self-contained binary, eliminating the need for any external dependencies.
$ is_ready --help
Usage: is_ready [OPTIONS] --addr <ADDRESS> -- <COMMAND>...
Arguments:
<COMMAND>...
Options:
-t, --timeout <TIMEOUT> [default: 30]
-a, --addr <ADDRESS>
-h, --help Print help
-V, --version Print version
$ is_ready \
--timeout 10 \
--addr github.com:80 \
--addr google.com:80 \
-- echo "The addresses are available"
Connected to google.com:80 successfully
Connected to github.com:80 successfully
The addresses are available
is_ready
is optimized for running in a Docker container, and it is ideal to wait for the availability of other services such as databases, caches, or other services.
Example using the Docker Image:
# Set the version you want to download
ARG IS_READY_VERSION=1.0.0
FROM ghcr.io/stavrospanakakis/is_ready:$IS_READY_VERSION AS is_ready
FROM alpine:3.19
RUN apk add --no-cache curl
# Download the binary
COPY --from=is_ready /is_ready /usr/local/bin/is_ready
...
...
Example using curl
:
FROM alpine:3.19
RUN apk add --no-cache curl
# Set the version you want to download
ENV IS_READY_VERSION=v1.0.0
# Download the binary
RUN curl -L https://github.com/Stavrospanakakis/is_ready/releases/download/${IS_READY_VERSION}/is_ready_${IS_READY_VERSION}_x86_64-unknown-linux-musl.tar.gz | tar xzf - -C /usr/local/bin
...
...
Example Docker Compose:
version: '3'
services:
mysql:
image: mysql:8.0
app:
build: .
command: is_ready --timeout 10 --addr mysql:3306 -- echo "MySQL is ready"
is_ready
can be also used as a Docker container using the
ghcr.io/stavrospanakakis/is_ready
image from GitHub Container Registry.
$ VERSION=1.0.0
$ docker run --rm ghcr.io/stavrospanakakis/is_ready:$VERSION --version
is_ready 1.0.0
MIT