Because I explicitly wanted to avoid touching config. We want a simple method for checking flags that can't fail. Dealing with config doesn't give us that.
I don't think that using an environment variable to define feature flags is too terrible. We don't want to make it too easy ;-) Tim On 26/11/14 17:10, John Meinel wrote: > Given the constraints you just listed (globally set in the environment, > etc), why not just make it environment config, rather than > yet-another-way to set env config? > > John > =:-> > > > On Wed, Nov 26, 2014 at 5:22 AM, Tim Penhey <tim.pen...@canonical.com > <mailto:tim.pen...@canonical.com>> wrote: > > On 26/11/14 14:18, Andrew Wilkins wrote: > > On Wed, Nov 26, 2014 at 6:47 AM, Tim Penhey <tim.pen...@canonical.com > <mailto:tim.pen...@canonical.com> > > <mailto:tim.pen...@canonical.com > <mailto:tim.pen...@canonical.com>>> wrote: > > > > Hi all, > > > > There are often times when we want to hook up features for > testing that > > we don't want exposed to the general user community. > > > > In the past we have hooked things up in master, then when the > release > > branch is made, we have had to go and change things there. > This is a > > terrible way to do it. > > > > Here is my proposal: > > > > http://reviews.vapour.ws/r/531/diff/# > > > > We have an environment variable called JUJU_FEATURE_FLAGS. It > contains > > comma delimited strings that are used as flags. > > > > The value is read when the program initializes and is not mutable. > > > > Simple checks can be used in the code: > > > > if featureflag.Enabled("foo") { > > // do foo like things > > } > > > > Thoughts and suggestions appreciated, but I don't want to have the > > bike-shedding go on too long. > > > > > > I like the idea of having flags. > > > > I'm not sure about setting it at bootstrap and it being global. How > > would we test upgrade scenarios where some agents have the > feature, and > > others don't? > > The idea is that the machines get the flags when they are deployed using > environment variables in the upstart script (or other service starting > thingimy-widget). > > All agents in a given environment would have the same flags. > > I'm in two minds about whether feature flags should be able to be turned > on and off on the fly. > > I'm mostly against it as we may have different workers for feature > flags, and this would mean that we'd then have to code watchers for the > flags in order to start and stop workers based on flag changes. > > I think simple is better here. > > Tim > > > -- > Juju-dev mailing list > Juju-dev@lists.ubuntu.com <mailto:Juju-dev@lists.ubuntu.com> > Modify settings or unsubscribe at: > https://lists.ubuntu.com/mailman/listinfo/juju-dev > > -- Juju-dev mailing list Juju-dev@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/juju-dev
