wait-for-service

Waits for a dependency before continuing. It's meant to be used in startup scripts like Docker's entrypoint. This project is forked from http://github.com/wlatanowicz/wait-for-service

Installing

pip install wait-for-service

Usage

wait-for-service dependency-url-1 dependency-url-2 ... dependency-url-n

ie:

wait-for-service https://my-server/healthz/ psql://user@db-host/db-name

Available checks

HTTP(s)

HTTP and HTTPS are available by default. Follows redirects; only response with HTTP code 2XX is accepted as valid.

Accepted URL schemas

• http://
• https://

Example

wait-for-service https://my-server/healthz/ http://my-server/healthz/

PostgreSQL

RDBMS has to accept connection and allow to perform simple SELECT query.

Installation

pip install wait-for-service[postgres]

Accepted URL schemas

• postgres://
• postgresql://
• psql://

Example

wait-for-service psql://admin:password@db-host/db_name

MySQL

RDBMS has to accept connection and allow to perform simple SELECT query.

Installation

pip install wait-for-service[mysql]

Accepted URL schemas

• mysql://

Example

wait-for-service mysql://admin:password@db-host/db_name

Redis

Rdis has to accept connection to selected database (defaults to 0).

Installation

pip install wait-for-service[redis]

Accepted URL schemas

• redis://

Example

wait-for-service redis://redis-host/5

Memcached

Memcached has to accept connection.

Installation

pip install wait-for-service[memcached]

Accepted URL schemas

• memcached://

Example

wait-for-service memcached://memcached-host/

MongoDB

MongoDB has to accept connection.

Installation

pip install wait-for-service[mongodb]

Accepted URL schemas

• mongodb://

Example

wait-for-service mongodb://admin:password@db-host/db_name

RabbitMQ

RabbitMQ has to accept connection to given vhost. You can use optional querystring params require_queue and require_exchange to additionaly check if particular queue or exchange exists (check will fail otherwise).

Installation

pip install wait-for-service[amqp]

Accepted URL schemas

• amqp://

Example

wait-for-service amqp://admin:password@rabbit-host/vhost
wait-for-service amqp://admin:password@rabbit-host/vhost?require_queue=myqueue
wait-for-service amqp://admin:password@rabbit-host/vhost?require_exchange=myexchange
wait-for-service amqp://admin:password@rabbit-host/vhost?require_exchange=myexchange&require_exchange=mysecondexchange&require_queue=myqueue&require_queue=mysecondqueue

Apache Kafka

Kafka has to accept connection. In HA mode (node count > 1) only one node is required to accept the connection.

Installation

pip install wait-for-service[kafka]

Accepted URL schemas

If port is not specified 9092 will be assumed, topic is optional but recommended

• kafka://bootstrap-host
• kafka://bootstrap-host:9092
• kafka://bootstrap-host,bootstrap-host2:9092
• kafka://bootstrap-host/topic
• kafka://bootstrap-host:9092/topic
• kafka://bootstrap-host,bootstrap-host2:9092/topic

Example

wait-for-service kafka://kafka-host/
wait-for-service kafka://kafka-first-host/,kafka://kafka-second-host/

TCP

Plain TCP is available by default. Service port is required.

Accepted URL schemas

• tcp://

Example

wait-for-service tcp://my-server:7624

Unix

Unix sockets are available by default.

Accepted URL schemas

• unix://

Example

wait-for-service unix:///var/run/docker.sock