Use default solana config for anchor idl fetch

Signed-off-by: Nikhil B N <nikhilbn365@gmail.com>

CHANGELOG.md

@@ -22,6 +22,7 @@ incremented for features.
 * lang: Add check that declared id == program id ([#1451](https://github.com/project-serum/anchor/pull/1451)).
 * ts: Added float types support ([#1425](https://github.com/project-serum/anchor/pull/1425)).
 * cli: Add `--skip-lint` option to disable check linting introduced in ([#1452](https://github.com/project-serum/anchor/pull/1452)) for rapid prototyping ([#1482](https://github.com/project-serum/anchor/pull/1482)).
+* cli: Add support for `anchor idl fetch` to work outside anchor workspace ([#1509](https://github.com/project-serum/anchor/pull/1509)).
 
 ### Fixes
 

Cargo.lock

@@ -165,6 +165,7 @@ dependencies = [
  "serde_json",
  "serum-common",
  "shellexpand",
+ "solana-cli-config",
  "solana-client",
  "solana-program",
  "solana-sdk",
@@ -1089,12 +1090,6 @@ dependencies = [
  "syn 0.15.44",
 ]
 
-[[package]]
-name = "dtoa"
-version = "0.4.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56899898ce76aaf4a0f24d914c97ea6ed976d42fec6ad33fcbb0a1103e07b2b0"
-
 [[package]]
 name = "ed25519"
 version = "1.2.0"
@@ -2844,12 +2839,12 @@ dependencies = [
 
 [[package]]
 name = "serde_yaml"
-version = "0.8.21"
+version = "0.8.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8c608a35705a5d3cdc9fbe403147647ff34b921f8e833e49306df898f9b20af"
+checksum = "a4a521f2940385c165a24ee286aa8599633d162077a54bdcae2a6fd5a7bfa7a0"
 dependencies = [
- "dtoa",
  "indexmap",
+ "ryu",
  "serde",
  "yaml-rust",
 ]

cli/Cargo.toml

@@ -27,6 +27,7 @@ serde = { version = "1.0.122", features = ["derive"] }
 solana-sdk = "1.8.5"
 solana-program = "1.8.5"
 solana-client = "1.8.5"
+solana-cli-config = "1.8.5"
 serum-common = { git = "https://github.com/project-serum/serum-dex", features = ["client"] }
 dirs = "3.0"
 heck = "0.3.1"

cli/src/config.rs

@@ -4,11 +4,13 @@ use anyhow::{anyhow, Error, Result};
 use clap::{ArgEnum, Parser};
 use heck::SnakeCase;
 use serde::{Deserialize, Serialize};
+use solana_cli_config::{Config as SolanaConfig, CONFIG_FILE};
 use solana_sdk::pubkey::Pubkey;
 use solana_sdk::signature::{Keypair, Signer};
 use std::collections::BTreeMap;
 use std::convert::TryFrom;
 use std::fs::{self, File};
+use std::io;
 use std::io::prelude::*;
 use std::ops::Deref;
 use std::path::Path;
@@ -445,6 +447,16 @@ impl FromStr for Config {
     }
 }
 
+pub fn get_solana_cfg_url() -> Result<String, io::Error> {
+    let config_file = CONFIG_FILE.as_ref().ok_or_else(|| {
+        io::Error::new(
+            io::ErrorKind::NotFound,
+            "Default Solana config was not found",
+        )
+    })?;
+    SolanaConfig::load(config_file).map(|config| config.json_rpc_url)
+}
+
 fn ser_programs(
     programs: &BTreeMap<Cluster, BTreeMap<String, ProgramDeployment>>,
 ) -> BTreeMap<String, BTreeMap<String, serde_json::Value>> {

cli/src/lib.rs

@@ -1401,16 +1401,13 @@ fn fetch_idl(cfg_override: &ConfigOverride, idl_addr: Pubkey) -> Result<Idl> {
         Some(cfg) => cluster_url(&cfg),
         None => {
             // If the command is not run inside a workspace,
-            // provider.cluster option has to be provided
+            // cluster_url will be used from default solana config
+            // provider.cluster option can be used to override this
+
             if let Some(cluster) = cfg_override.cluster.clone() {
-                let is_localnet = cluster == Cluster::Localnet;
-                match is_localnet {
-                    // If Cluster is Localnet, default url will be used
-                    true => "http://localhost:8899".to_string(),
-                    false => cluster.url().to_string(),
-                }
+                cluster.url().to_string()
             } else {
-                return Err(anyhow!("provider.cluster option required"));
+                config::get_solana_cfg_url()?
             }
         }
     };