[ENH] CLI - Set Chroma env variables (#4711)

## Description of changes

Adding `chroma db connect --env-file` which sets environment variables
required for connecting to ChromaCloud in the `.env` file in the current
directory (or create it). The `chroma db connect --env-vars` option will
output to the terminal.

## Test plan

Manual testing.

## Documentation Changes

Included in this PR under CLI docs.

Author: itaismith

docs/docs.trychroma.com/markdoc/content/cli/commands/db.md

@@ -12,6 +12,20 @@ The output code snippet will already have the API key of your profile set for th
 chroma db connect [db_name] [--language python/JS/TS]
 ```
 
+The `connect` command can also add Chroma environment variables (`CHROMA_API_KEY`, `CHROMA_TENANT`, and `CHROMA_DATABASE`) to a `.env` file in your current working directory. It will create a `.env` file for you if it doesn't exist:
+
+```terminal
+chroma db connect [db_name] --env-file
+```
+
+If you prefer to simply output these variables to your terminal use:
+
+```terminal
+chroma db connect [db_name] --env-vars
+```
+
+Setting these environment variables will allow you to concisely instantiate the `CloudClient` with no arguments.
+
 ### Create
 
 The `create` command lets you create a database on Chroma Cloud. It has the `name` argument, which is the name of the DB you want to create. If you don't provide it, the CLI will prompt you to choose a name.

rust/cli/src/commands/db.rs

@@ -1,19 +1,24 @@
 use crate::client::admin_client::get_admin_client;
 use crate::ui_utils::copy_to_clipboard;
-use crate::utils::{get_current_profile, CliError, Profile, UtilsError, SELECTION_LIMIT};
+use crate::utils::{
+    get_current_profile, CliError, Profile, UtilsError, CHROMA_API_KEY_ENV_VAR,
+    CHROMA_DATABASE_ENV_VAR, CHROMA_TENANT_ENV_VAR, SELECTION_LIMIT,
+};
 use chroma_types::Database;
 use clap::{Args, Subcommand, ValueEnum};
 use colored::Colorize;
 use dialoguer::theme::ColorfulTheme;
 use dialoguer::{Input, Select};
-use std::fmt;
+use std::error::Error;
+use std::path::Path;
+use std::{fmt, fs};
 use strum::IntoEnumIterator;
 use strum_macros::EnumIter;
 use thiserror::Error;
 
 #[derive(Debug, Error)]
 pub enum DbError {
-    #[error("")]
+    #[error("No databases found")]
     NoDBs,
     #[error("Database name cannot be empty")]
     EmptyDbName,
@@ -23,6 +28,8 @@ pub enum DbError {
     DbNotFound(String),
     #[error("Failed to get runtime for DB commands")]
     RuntimeError,
+    #[error("Failed to create or update .env file with Chroma environment variables")]
+    EnvFile,
 }
 
 #[derive(Debug, Clone, ValueEnum, EnumIter)]
@@ -98,6 +105,10 @@ pub struct ConnectArgs {
         help = "The programming language to use for the connection snippet"
     )]
     language: Option<Language>,
+    #[clap(long = "env-file", default_value_t = false, conflicts_with_all = ["language", "env_vars"], help = "Add Chroma environment variables to a .env file in the current directory")]
+    env_file: bool,
+    #[clap(long = "env-vars", default_value_t = false, conflicts_with_all = ["language", "env_file"], help = "Output Chroma environment variables")]
+    env_vars: bool,
 }
 
 #[derive(Args, Debug)]
@@ -147,6 +158,13 @@ fn no_dbs_message(profile_name: &str) -> String {
     )
 }
 
+fn env_file_created_message() -> String {
+    format!(
+        "{}",
+        "Chroma environment variables set in .env!".blue().bold()
+    )
+}
+
 fn select_language_message() -> String {
     "Which language would you like to use?".to_string()
 }
@@ -318,6 +336,48 @@ fn confirm_db_deletion(name: &str) -> Result<bool, CliError> {
     Ok(confirm.eq(name))
 }
 
+fn create_env_connection(current_profile: Profile, db_name: String) -> Result<(), Box<dyn Error>> {
+    let env_path = ".env";
+    let chroma_keys = [
+        CHROMA_API_KEY_ENV_VAR,
+        CHROMA_TENANT_ENV_VAR,
+        CHROMA_DATABASE_ENV_VAR,
+    ];
+
+    let mut lines = Vec::new();
+
+    if Path::new(env_path).exists() {
+        let content = fs::read_to_string(env_path)?;
+
+        for line in content.lines() {
+            let keep = if let Some(eq_pos) = line.find('=') {
+                let key = line[..eq_pos].trim();
+                !chroma_keys.contains(&key)
+            } else {
+                true
+            };
+
+            if keep {
+                lines.push(line.to_string());
+            }
+        }
+    }
+
+    lines.push(format!(
+        "{}={}",
+        CHROMA_API_KEY_ENV_VAR, current_profile.api_key
+    ));
+    lines.push(format!(
+        "{}={}",
+        CHROMA_TENANT_ENV_VAR, current_profile.tenant_id
+    ));
+    lines.push(format!("{}={}", CHROMA_DATABASE_ENV_VAR, db_name));
+
+    fs::write(env_path, lines.join("\n") + "\n")?;
+
+    Ok(())
+}
+
 pub async fn connect(args: ConnectArgs, current_profile: Profile) -> Result<(), CliError> {
     let admin_client = get_admin_client(Some(&current_profile), args.db_args.dev);
     let dbs = admin_client.list_databases().await?;
@@ -331,6 +391,21 @@ pub async fn connect(args: ConnectArgs, current_profile: Profile) -> Result<(),
         return Err(CliError::Db(DbError::DbNotFound(name)));
     }
 
+    if args.env_file {
+        if create_env_connection(current_profile, name).is_err() {
+            return Err(DbError::EnvFile.into());
+        }
+        println!("{}", env_file_created_message());
+        return Ok(());
+    }
+
+    if args.env_vars {
+        println!("{}={}", CHROMA_API_KEY_ENV_VAR, current_profile.api_key);
+        println!("{}={}", CHROMA_TENANT_ENV_VAR, current_profile.tenant_id);
+        println!("{}={}", CHROMA_DATABASE_ENV_VAR, name);
+        return Ok(());
+    }
+
     let language = match args.language {
         Some(language) => language,
         None => select_language()?,

rust/cli/src/utils.rs

@@ -34,6 +34,9 @@ pub const CHROMA_DIR: &str = ".chroma";
 pub const CREDENTIALS_FILE: &str = "credentials";
 const CONFIG_FILE: &str = "config.json";
 pub const SELECTION_LIMIT: usize = 5;
+pub const CHROMA_API_KEY_ENV_VAR: &str = "CHROMA_API_KEY";
+pub const CHROMA_TENANT_ENV_VAR: &str = "CHROMA_TENANT";
+pub const CHROMA_DATABASE_ENV_VAR: &str = "CHROMA_DATABASE";
 
 #[derive(Debug, Error)]
 pub enum CliError {