I think the guidance from clig.dev is pretty clear - when the configuration is generally stable from one invocation to the next, using environment variables is nice. Imagine starting a container, you set ZK_HOST once and then it's good for every invocation of the tools. Otherwise you have to have logic for adding that flag to every command, which probably looks like appending "--zk-host $ZK_HOST" every time, so you're setting the environment variable in your deployment anyway.
On Thu, Mar 6, 2025 at 8:48 AM David Eric Pugh <de...@yahoo.com.invalid> wrote: > I've been thinking about the use of environment variables in the Solr CLI, > and trying to figure out why it feels like a bad thing... I think that > the reason I don't like them is that it feels like we are injecting "magic" > into our CLI, and this makes them actually more brittle and difficult to > comprehend. > > Some recent related tickets: > https://github.com/apache/solr-operator/issues/762 > https://github.com/apache/solr/pull/3240 > > In the recent revamp of the CLI a LOT of work went into makign the CLI > more obvious. We went through all the various arguments and cleaned them > up so we didn't have different tools have overlapping parameters. We > standared the descriptive terminology we used for the various options. > And we tried to make the CLI smarter about required and optional > parameters. Lastly, for situations where you could do A or B, like passing > in Solr URL OR a ZK Host, we actually enforce that. > > We embraced Commons CLI, not because it's the best tool, but because it's > the most widely used one in our code base, and pushed it to be used across > all the CLI scripts (Prometheus Exporter, core CLI, the HDFS scripts. > > So... Why this rant? > > It feels like using the environment variables to look up the connection > information pattern that we are using goes against making our CLI clearer, > and is why we are seeing various bugs in solr-operator. The contract > between the CLI and the caller is the set of options that you pass to the > CLI. Using environment variables avoids the checking that Commmons CLI > does for us. We should be explicit when we call a script and pass in > everything it needs. > > I was very much hoping the guide lines we were using to steer us in > revamping the CLI would support my contention that the use of the > environment variables to specify connectivity options is a bad practice, > https://clig.dev/#configuration, but unfortunantly it doesn't clearly > state that;-) > > I mostly wanted to share this to get it off my chest, versus any specific > "we must change this now" request.... > Thanks for reading! > Eric >
