feat(k8s): Add detect env vars option (#4488)

* feat(k8s): Add detect env vars option

Have added the option to trigger the k8s module based on what env vars
are set, this has been done in a backwards compatible way so if nothing
is changed from the defaults the module will still behave the same way
as before. This is similar to what I did in #4486 for the python module
and if goes well I'd like to rollout to other modules.

* Update src/modules/kubernetes.rs

Co-authored-by: David Knaack <davidkna@users.noreply.github.com>

* Update src/modules/kubernetes.rs

---------

Co-authored-by: David Knaack <davidkna@users.noreply.github.com>

4 files changed, 34 insertions, 5 deletions

diff --git a/.github/config-schema.json b/.github/config-schema.json
index 9f30f307b..bee19d817 100644
--- a/.github/config-schema.json
+++ b/.github/config-schema.json
@@ -952,6 +952,7 @@
       "default": {
         "context_aliases": {},
         "contexts": [],
+        "detect_env_vars": [],
         "detect_extensions": [],
         "detect_files": [],
         "detect_folders": [],
@@ -4256,6 +4257,13 @@
             "type": "string"
           }
         },
+        "detect_env_vars": {
+          "default": [],
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        },
         "contexts": {
           "default": [],
           "type": "array",
diff --git a/docs/config/README.md b/docs/config/README.md
index dcec83815..9756484de 100644
--- a/docs/config/README.md
+++ b/docs/config/README.md
@@ -2601,8 +2601,9 @@ This module is disabled by default.
 To enable it, set `disabled` to `false` in your configuration file.
 
 When the module is enabled it will always be active, unless any of
-`detect_extensions`, `detect_files` or `detect_folders` have been set in which
-case the module will only be active in directories that match those conditions.
+`detect_env_vars`, `detect_extensions`, `detect_files` or `detect_folders` have
+been set in which case the module will only be active in directories that match
+those conditions or one of the environmatal variable has been set.
 
 :::
 
@@ -2625,6 +2626,7 @@ and `user_alias` options instead.
 | `detect_extensions` | `[]`                                               | Which extensions should trigger this module.                          |
 | `detect_files`      | `[]`                                               | Which filenames should trigger this module.                           |
 | `detect_folders`    | `[]`                                               | Which folders should trigger this modules.                            |
+| `detect_env_vars`   | `[]`                                               | Which environmental variables should trigger this module              |
 | `contexts`          | `[]`                                               | Customized styles and symbols for specific contexts.                  |
 | `disabled`          | `true`                                             | Disables the `kubernetes` module.                                     |
 
diff --git a/src/configs/kubernetes.rs b/src/configs/kubernetes.rs
index 00523783b..312c73bd2 100644
--- a/src/configs/kubernetes.rs
+++ b/src/configs/kubernetes.rs
@@ -18,6 +18,7 @@ pub struct KubernetesConfig<'a> {
     pub detect_extensions: Vec<&'a str>,
     pub detect_files: Vec<&'a str>,
     pub detect_folders: Vec<&'a str>,
+    pub detect_env_vars: Vec<&'a str>,
     pub contexts: Vec<KubernetesContextConfig<'a>>,
 }
 
@@ -33,6 +34,7 @@ impl<'a> Default for KubernetesConfig<'a> {
             detect_extensions: vec![],
             detect_files: vec![],
             detect_folders: vec![],
+            detect_env_vars: vec![],
             contexts: vec![],
         }
     }
diff --git a/src/modules/kubernetes.rs b/src/modules/kubernetes.rs
index ef6a4a1f1..09a4cef40 100644
--- a/src/modules/kubernetes.rs
+++ b/src/modules/kubernetes.rs
@@ -107,6 +107,8 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         return None;
     };
 
+    let have_env_vars = context.detect_env_vars(&config.detect_env_vars);
+
     // If we have some config for doing the directory scan then we use it but if we don't then we
     // assume we should treat it like the module is enabled to preserve backward compatibility.
     let have_scan_config = [
@@ -127,7 +129,7 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         })
     });
 
-    if !is_kube_project.unwrap_or(true) {
+    if !is_kube_project.unwrap_or(true) && !have_env_vars {
         return None;
     }
 
@@ -320,7 +322,7 @@ users: []
     }
 
     #[test]
-    fn test_none_when_no_detected_files_or_folders() -> io::Result<()> {
+    fn test_none_when_no_detected_files_folders_or_env_vars() -> io::Result<()> {
         let dir = tempfile::tempdir()?;
 
         let filename = dir.path().join("config");
@@ -352,6 +354,7 @@ users: []
                 detect_files = ["k8s.ext"]
                 detect_extensions = ["k8s"]
                 detect_folders = ["k8s_folder"]
+                detect_env_vars = ["k8s_env_var"]
             })
             .collect();
 
@@ -361,7 +364,7 @@ users: []
     }
 
     #[test]
-    fn test_with_detected_files_and_folder() -> io::Result<()> {
+    fn test_with_detected_files_folder_and_env_vars() -> io::Result<()> {
         let dir = tempfile::tempdir()?;
 
         let filename = dir.path().join("config");
@@ -429,6 +432,19 @@ users: []
             })
             .collect();
 
+        let empty_dir = tempfile::tempdir()?;
+
+        let actual_env_var = ModuleRenderer::new("kubernetes")
+            .path(empty_dir.path())
+            .env("KUBECONFIG", filename.to_string_lossy().as_ref())
+            .env("TEST_K8S_ENV", "foo")
+            .config(toml::toml! {
+                [kubernetes]
+                disabled = false
+                detect_env_vars = ["TEST_K8S_ENV"]
+            })
+            .collect();
+
         let expected = Some(format!(
             "{} in ",
             Color::Cyan.bold().paint("☸ test_context")
@@ -437,6 +453,7 @@ users: []
         assert_eq!(expected, actual_file);
         assert_eq!(expected, actual_ext);
         assert_eq!(expected, actual_dir);
+        assert_eq!(expected, actual_env_var);
 
         dir.close()
     }