dbrandt / service_canary

Test access to other services, useful to validate your network access setup.

service_canary

A simple (web) app that checks connectivity to other services.

That admittedly sounds a bit useless, but is something I use when troubleshooting container deployments or to quickly see if I got the routing right... or messed those security groups in my AWS setup.

Prerequisites

The only real requirement is requests. Of course, then you can only test API connectivity.

Beyond API testing you might want to install:

• if you want to test RabbitMQ
• psycopg2 if you want to test PostgreSQL
• riak if you want to test Riak/RiakTS
• pymemcache if you wan to test memcached

Configuration

Configuration is done via environment variables or command line options. The environment variables looked for look like this:

CANARY_DB_<n>_TYPE
CANARY_DB_<n>_HOST
CANARY_DB_<n>_PORT
CANARY_DB_<n>_USER
CANARY_DB_<n>_PASS
CANARY_DB_<n>_DB_NAME
CANARY_DB_<n>_TEST_QUERY
CANARY_API_<n>_URL
CANARY_API_<n>_TOKEN
CANARY_API_<n>_ENDPOINT
CANARY_MEMCACHED_HOST
CANARY_MEMCACHED_PORT
CANARY_RABBITMQ_HOST
CANARY_RABBITMQ_PORT

The denotes a number, this is so you can test several nodes or several databases at once. You translate this to command line arguments by stripping the CANARY_ prefix and making it lowercase: CANARY_DB_1_TYPE becomes --db-1-type and so on.

Databases

Valid values for database type at this point:

• postgres (PostgreSQL)
• riak (Riak/RiakTS)

The test query and db name setting is optional. If you leave them out, the code will connect and issue a SELECT 1 for SQL-databases or a ping for Riak.