Input requested: considering requiring --ttl on all bkt invocations

[dimo414]

I am considering removing the default value of one minute from --ttl. This would be a breaking change to the CLI, which I generally want to avoid, so I'm soliciting input before making such a change.

This default is fairly arbitrary (it's a holdover from bash-cache which already discourages relying on the default); there's no reason to think a given invocation should use this value by default. The primary justification for keeping it is to have minimal caching be as simple as prepending bkt -- to a command, however I worry this is misleading as both callers and readers actually do need to understand the TTL semantics in order to understand what this does. bkt -- date; sleep 59; bkt -- date and bkt -- date; sleep 61; bkt -- date behave differently and a casual reading of these calls cannot discern this.

My real motivation, aside from the default value being poor, is related to #27 and potentially support caching without a TTL if a modtime file is specified instead. It's possible to implement #27 without removing this default (and specifying both a TTL and a modtime file will always be valid) but it would be a stronger feature if it could eliminate needing to specify a TTL, so I'd like to remove the TTL default before taking a swing at that feature.

My plan would be to cut a new minor version (it would be a major version bump but bkt is still a 0.*.* project) with just the removal of this default. Hopefully that will help existing usages relying on the default migrate safely.

Note the legacy behavior can be preserved trivially by adding export BKT_TTL=60s to your .bashrc (or setting the same variable in whichever environment needs it).

[dimo414]

I'm planning to make this change in 0.8.0, which will be cut soon.

[borestad]

Some food for thought. If bkt had a config file i.e $HOME/.bkt.yaml , this could be set by default in userland instead.

[dimo414]

True, but you could accomplish the same effect by setting the env var in your ~/.bashrc or similar. I'd be hesitant to make something like the TTL a globally-configured option for the same reasons I want to rip out the default in the first place - it really doesn't make much sense to have one.

But thanks for the suggestion - if you have particular use-cases for a .bkt config file of some sort feel free to start a discussion or open an FR!