Context

General request context collection. Collects data points like thread ID, process ID, and so on, for common middleware usage.

API

# all params come with defaults
context(
    namespace="service",
    scope="all",
    env="local",
    sha="dev",
    version="0.01",
    context_fn=get_context,
    getpid=os.getpid,
    gettid=thread.get_ident,
)

Context:

  • v - Logical product version
  • sha - Physical source tree version (e.g. Git SHA)
  • env - Development environment
  • pid - Process ID of current process running request
  • tid - Thread ID of current thread running request
  • uid - User ID for the current request
  • scope - Scope, i.e. module name
  • ns - Namespace, i.e. product name
  • rid - Request ID for correlation
  • rid_p - Parent request ID for correlation,

Usage

from formation.middleware import context

@client
class Google(object):
    base_uri = "https://google.com"
    middleware=[
        context(
            namespace="acme"
            scope="billing"
        )
    ]
    ...

Accessing context from your middleware:

from formation import _CONTEXT
def my_mware(mime_type):
    def my_mware_middleware(ctx, call):
        c = ctx.get(_CONTEXT)
        print(c)
        return call(ctx)

    return my_mware_middleware
← Context LoggerDuration →