feat(sre): add Kubernetes YAML linting and schema validation

Enable yamlls with Kubernetes schema (schemaStore) for inline diagnostics
on manifest files in common SRE paths (manifests/, k8s/, deploy/, etc.).
Wire up nvim-lint with yamllint for YAML syntax checking on save/enter.
Disable cmp completion for YAML buffers — diagnostics only, no autocomplete.
Add deployment.yaml fixture and extend CI treesitter tests to cover yaml.

Author: Venkata Subramani Renduchintala

lua/autocmds.lua

@@ -45,6 +45,14 @@ vim.api.nvim_create_autocmd("FileType", {
 	end,
 })
 
+-- Disable cmp autocompletion for YAML — we want linting/diagnostics only
+vim.api.nvim_create_autocmd("FileType", {
+  pattern = "yaml",
+  callback = function()
+    require("cmp").setup.buffer({ enabled = false })
+  end,
+})
+
 -- Disable automatic line breaks
 vim.api.nvim_create_autocmd("FileType", {
   pattern = "*",

lua/lsp/init.lua

@@ -114,10 +114,32 @@ if lspconfig then
 		capabilities = capabilities,
 	})
 
-	-- YAMLs
+	-- YAMLs — diagnostics only, no completion
   lspconfig("yamlls", {
+    autostart = true,
     capabilities = capabilities,
-  	autostart = false,
+    settings = {
+      yaml = {
+        validate = true,
+        hover = true,
+        completion = false,
+        schemaStore = {
+          enable = true,
+          url = "https://www.schemastore.org/api/json/catalog.json",
+        },
+        schemas = {
+          -- Kubernetes manifests in common SRE directory layouts
+          kubernetes = {
+            "manifests/**/*.yaml",
+            "k8s/**/*.yaml",
+            "kubernetes/**/*.yaml",
+            "deploy/**/*.yaml",
+            "templates/**/*.yaml",
+            "chart/templates/**/*.yaml",
+          },
+        },
+      },
+    },
   })
 
   -- CMake Language Server

lua/plugins/configs/mason.lua

@@ -84,6 +84,18 @@ return {
 				},
 				ignore_install = {},
 			})
+
+			-- Wire up nvim-lint: which linters run per filetype and when
+			local lint = require("lint")
+			lint.linters_by_ft = {
+				yaml = { "yamllint" },
+			}
+			vim.api.nvim_create_autocmd({ "BufWritePost", "BufEnter" }, {
+				pattern = { "*.yaml", "*.yml" },
+				callback = function()
+					lint.try_lint()
+				end,
+			})
 		end,
 	},
 	{

test/fixtures/deployment.yaml

@@ -0,0 +1,29 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: hello-app
+  namespace: default
+  labels:
+    app: hello-app
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app: hello-app
+  template:
+    metadata:
+      labels:
+        app: hello-app
+    spec:
+      containers:
+        - name: hello-app
+          image: nginx:1.25
+          ports:
+            - containerPort: 80
+          resources:
+            requests:
+              cpu: "100m"
+              memory: "128Mi"
+            limits:
+              cpu: "250m"
+              memory: "256Mi"

test/install_parsers.lua

@@ -1,7 +1,7 @@
 -- Headless treesitter parser installer for CI.
 -- Uses TSInstall! + vim.wait() polling parser .so files on disk.
 -- Exit code 1 on timeout so the CI step fails visibly.
-local langs = { 'go', 'terraform', 'hcl' }
+local langs = { 'go', 'terraform', 'hcl', 'yaml' }
 local parser_dir = vim.fn.stdpath('data') .. '/lazy/nvim-treesitter/parser/'
 
 local function installed(lang)

test/validate_treesitter.lua

@@ -39,6 +39,7 @@ end
 local cfg = '/home/dev/.config/nvim'
 test_parser('go',        cfg .. '/test/fixtures/hello.go')
 test_parser('terraform', cfg .. '/test/fixtures/main.tf')
+test_parser('yaml',      cfg .. '/test/fixtures/deployment.yaml')
 
 if #errors > 0 then
   for _, err in ipairs(errors) do