nvim/lua/setup/lspinstall.lua

local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities.textDocument.completion.completionItem.documentationFormat = { 'markdown', 'plaintext' }
capabilities.textDocument.completion.completionItem.snippetSupport = true
capabilities.textDocument.completion.completionItem.preselectSupport = true
capabilities.textDocument.completion.completionItem.insertReplaceSupport = true
capabilities.textDocument.completion.completionItem.labelDetailsSupport = true
capabilities.textDocument.completion.completionItem.deprecatedSupport = true
capabilities.textDocument.completion.completionItem.commitCharactersSupport = true
capabilities.textDocument.completion.completionItem.tagSupport = { valueSet = { 1 } }
capabilities.offsetEncoding = { 'utf-16' }
capabilities.textDocument.completion.completionItem.resolveSupport = {
  properties = {
    'documentation',
    'detail',
    'additionalTextEdits',
  },
}

OpenDiagFloat = function ()
  for _, winid in pairs(vim.api.nvim_tabpage_list_wins(0)) do
   if vim.api.nvim_win_get_config(winid).zindex then
     return
   end
  end
  vim.diagnostic.open_float({focusable = false})
end

local on_attach = function(client, bufnr)
  local function buf_set_option(...)
    vim.api.nvim_buf_set_option(bufnr, ...)
  end

  buf_set_option('omnifunc', 'v:lua.vim.lsp.omnifunc')
  vim.api.nvim_buf_set_option(0, 'formatexpr', 'v:lua.vim.lsp.formatexpr()')

  -- Mappings.
  local opts ={ noremap = true, silent = true, buffer = true }
  vim.keymap.set('n', '<space>,', vim.lsp.diagnostic.goto_prev, opts )
  vim.keymap.set('n', '<space>;', vim.lsp.diagnostic.goto_next, opts)
  vim.keymap.set('n', '<space>a', vim.lsp.buf.code_action, opts)
  vim.keymap.set('n', '<space>d', vim.lsp.buf.definition, opts)
  vim.keymap.set('n', '<space>e', vim.lsp.buf.declaration, opts)
  vim.keymap.set('n', '<space>h', vim.lsp.buf.hover, opts)
  vim.keymap.set('n', '<space>c', vim.lsp.buf.outgoing_calls, opts)
  vim.keymap.set('n', '<space>C', vim.lsp.buf.incoming_calls, opts)
  vim.keymap.set('n', '<space>m', vim.lsp.buf.rename, opts)
  local tele_builtins = require('telescope.builtin')
  vim.keymap.set('n', '<C-t>', tele_builtins.lsp_dynamic_workspace_symbols, opts)
  vim.keymap.set('n', '<space>D', vim.lsp.buf.type_definition, opts)
  vim.keymap.set('n', '<C-k>', vim.lsp.buf.signature_help, opts)
  vim.keymap.set('n', '<space>r', tele_builtins.lsp_references, opts)
  vim.keymap.set('n', '<A-m>', '<cmd>Telescope aerial<cr>', opts)
  vim.keymap.set('n', '<space>v', function () tele_builtins.diagnostics({bufnr = 0}) end, opts)
  vim.keymap.set('n', '<A-o>', '<cmd>ClangdSwitchSourceHeader<CR>', opts)

  vim.cmd([[autocmd CursorHold <buffer> lua OpenDiagFloat()]])

  -- Set some keybinds conditional on server capabilities
  if client.server_capabilities.documentFormattingProvider then
    vim.keymap.set('n', '<space>f', vim.lsp.buf.format, opts)
  end
  if client.server_capabilities.documentRangeFormattingProvider then
    vim.keymap.set('v', '<space>f', vim.lsp.buf.range_formatting, opts)
  end

  -- Set autocommands conditional on server_capabilities
  if client.server_capabilities.document_highlight then
    vim.api.nvim_exec(
      [[
      hi LspReferenceRead cterm=bold ctermbg=red guibg=DarkGreen
      hi LspReferenceWrite cterm=bold ctermbg=red guibg=DarkRed
      augroup lsp_document_highlight
        autocmd! * <buffer>
        autocmd CursorHold <buffer> lua vim.lsp.buf.document_highlight()
        autocmd CursorHoldI <buffer> lua vim.lsp.buf.document_highlight()
        autocmd CursorMoved <buffer> lua vim.lsp.buf.clear_references()
      augroup END
    ]],
      false
    )
  end
  require('lsp_signature').on_attach({
    bind = true, -- This is mandatory, otherwise border config won't get registered.
    handler_opts = {
      border = 'single',
    },
    hi_parameter = 'IncSearch',
  }, bufnr)
  require("aerial").on_attach(client, bufnr)
end

local lsp_installer = require('nvim-lsp-installer')

local servers = {
  'pyright',
  'cmake',
  'clangd',
  'jsonls',
  'sumneko_lua',
  'dockerls',
}

for _, name in pairs(servers) do
  local server_is_found, server = lsp_installer.get_server(name)
  if server_is_found then
    if not server:is_installed() then
      print('Installing ' .. name)
      server:install()
    end
  end
end

lsp_installer.on_server_ready(function(server)
  local opts = {
    on_attach = on_attach,
    capabilities = capabilities,
  }

  -- (optional) Customize the options passed to the server
  if server.name == 'clangd' then
    return
  end

  if server.name == 'sumneko_lua' then
    local lua_rtp = vim.split(package.path, ';')
    table.insert(lua_rtp, 'lua/?.lua')
    table.insert(lua_rtp, 'lua/?/init.lua')
    opts.settings = {
      Lua = {
        runtime = {
          -- Tell the language server which version of Lua you're using (most likely LuaJIT in the case of Neovim)
          version = 'LuaJIT',
          -- Setup your lua path
          path = lua_rtp,
        },
        diagnostics = {
          -- Get the language server to recognize the `vim` global
          globals = { 'vim', 'use' },
        },
        workspace = {
          -- Make the server aware of Neovim runtime files
          library = vim.api.nvim_get_runtime_file('', true),
        },
        -- Do not send telemetry data containing a randomized but unique identifier
        telemetry = {
          enable = false,
        },
      },
    }
  end
  if server.name == 'yamlls' then
    opts.settings = {
      yaml = {
        validate = false
      }
    }
  end

  -- This setup() function is exactly the same as lspconfig's setup function (:help lspconfig-quickstart)
  server:setup(opts)
  vim.cmd([[ do User LspAttachBuffers ]])
end)

local null_ls = require('null-ls')
null_ls.setup({
  sources = {
    null_ls.builtins.code_actions.gitsigns,
    null_ls.builtins.formatting.autopep8,
    null_ls.builtins.formatting.prettier,
    null_ls.builtins.diagnostics.flake8,
    null_ls.builtins.formatting.isort,
    null_ls.builtins.formatting.cmake_format,
  },
  on_attach = on_attach,
  capabilities = capabilities,
})
vim.diagnostic.config({ virtual_text = true })

require('clangd_extensions').setup({
  server = {
    on_attach = on_attach,
    capabilities = capabilities,
    cmd = { 'clangd', '--compile-commands-dir=build_nvim' },
  },
})