From 0d620018fe01edba30eb233cc2c75f757757ab53 Mon Sep 17 00:00:00 2001
From: Kristin Laemmert <mildwonkey@users.noreply.github.com>
Date: Tue, 19 May 2020 15:32:36 -0400
Subject: [PATCH] provider cache: log errors and validate dir exists (#24993)

* providercache: add logging for errors from getproviders.SearchLocalDirectory

providercache.fillMetaCache() was silently swallowing errors when
searching the cache directory. This commit logs the error without
changing the behavior otherwise.

* command/cliconfig: validate plugin cache dir exists

The plugin cache directory must exist for terraform to use it, so we
will add a check at the begining.
---
 command/cliconfig/cliconfig.go      | 9 +++++++++
 command/cliconfig/cliconfig_test.go | 6 ++++++
 internal/providercache/dir.go       | 1 +
 3 files changed, 16 insertions(+)

diff --git a/command/cliconfig/cliconfig.go b/command/cliconfig/cliconfig.go
index 2aecfb9d12..7ac6eeb0be 100644
--- a/command/cliconfig/cliconfig.go
+++ b/command/cliconfig/cliconfig.go
@@ -273,6 +273,15 @@ func (c *Config) Validate() tfdiags.Diagnostics {
 		)
 	}
 
+	if c.PluginCacheDir != "" {
+		_, err := os.Stat(c.PluginCacheDir)
+		if err != nil {
+			diags = diags.Append(
+				fmt.Errorf("The specified plugin cache dir %s cannot be opened: %s", c.PluginCacheDir, err),
+			)
+		}
+	}
+
 	return diags
 }
 
diff --git a/command/cliconfig/cliconfig_test.go b/command/cliconfig/cliconfig_test.go
index a84e825b3b..d09ffff7b7 100644
--- a/command/cliconfig/cliconfig_test.go
+++ b/command/cliconfig/cliconfig_test.go
@@ -193,6 +193,12 @@ func TestConfigValidate(t *testing.T) {
 			},
 			1, // no more than one provider_installation block allowed
 		},
+		"plugin_cache_dir does not exist": {
+			&Config{
+				PluginCacheDir: "fake",
+			},
+			1, // The specified plugin cache dir %s cannot be opened
+		},
 	}
 
 	for name, test := range tests {
diff --git a/internal/providercache/dir.go b/internal/providercache/dir.go
index 1c1ade7b73..72688f92ec 100644
--- a/internal/providercache/dir.go
+++ b/internal/providercache/dir.go
@@ -136,6 +136,7 @@ func (d *Dir) fillMetaCache() error {
 
 	allData, err := getproviders.SearchLocalDirectory(d.baseDir)
 	if err != nil {
+		log.Printf("[TRACE] providercache.fillMetaCache: error while scanning directory %s: %s", d.baseDir, err)
 		return err
 	}