Simple Healthchecker

The goal is to provide a minimal, lightweight http client to use for healthchecking of applications inside Docker containers. To be compatible with Docker, the exit code for failures is always 1.

Dependencies:

• Only a C library (musl on Alpine, for example)

Usage:

hc server port host-header path

Where:

• server is the name or ip of the service endpoint
• port is the port on which the service is listening
• host-header is the value to include in the http host header. This might be the same as or different from the server value
• path is the URI to request, such as / or /directory/file.ext

Dockerfile Example:

HEALTHCHECK --interval=30s --timeout=3s \
  CMD ["/sbin/hc", "localhost", "8080", "api.mysite.dom", "/"]