kubernetes: misc fixes

- don't install unnecessary binaries
- remove go-bindata, already vendored by upstream
- use installShellFiles, add kubeadm completion
- require kubeadm/kubectl so installPhase can't be broken

pkgs/applications/networking/cluster/kubernetes/default.nix

@@ -1,7 +1,14 @@
-{ stdenv, lib, fetchFromGitHub, removeReferencesTo, which, go, go-bindata, makeWrapper, rsync
+{ stdenv
+, lib
+, fetchFromGitHub
+, removeReferencesTo
+, which
+, go
+, makeWrapper
+, rsync
+, installShellFiles
+
 , components ? [
-    "cmd/kubeadm"
-    "cmd/kubectl"
     "cmd/kubelet"
     "cmd/kube-apiserver"
     "cmd/kube-controller-manager"
@@ -11,8 +18,6 @@
   ]
 }:
 
-with lib;
-
 stdenv.mkDerivation rec {
   pname = "kubernetes";
   version = "1.19.4";
@@ -24,9 +29,9 @@ stdenv.mkDerivation rec {
     sha256 = "05gisihrklkzsdsrrmvmqlfwfdx73jbwd5668n5wa5hp432qyvwi";
   };
 
-  nativeBuildInputs = [ removeReferencesTo makeWrapper which go rsync go-bindata ];
+  nativeBuildInputs = [ removeReferencesTo makeWrapper which go rsync installShellFiles ];
 
-  outputs = ["out" "man" "pause"];
+  outputs = [ "out" "man" "pause" ];
 
   postPatch = ''
     # go env breaks the sandbox
@@ -41,7 +46,10 @@ stdenv.mkDerivation rec {
     patchShebangs ./hack
   '';
 
-  WHAT=concatStringsSep " " components;
+  WHAT = lib.concatStringsSep " " ([
+    "cmd/kubeadm"
+    "cmd/kubectl"
+  ] ++ components);
 
   postBuild = ''
     ./hack/update-generated-docs.sh
@@ -49,11 +57,12 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    mkdir -p "$out/bin" "$out/share/bash-completion/completions" "$out/share/zsh/site-functions" "$man/share/man" "$pause/bin"
+    for p in $WHAT; do
+      install -D _output/local/go/bin/''${p##*/} -t $out/bin
+    done
 
-    cp _output/local/go/bin/* "$out/bin/"
-    cp build/pause/pause "$pause/bin/pause"
-    cp -R docs/man/man1 "$man/share/man"
+    install -D build/pause/pause -t $pause/bin
+    installManPage docs/man/man1/*.[1-9]
 
     cp cluster/addons/addon-manager/kube-addons.sh $out/bin/kube-addons
     patchShebangs $out/bin/kube-addons
@@ -61,19 +70,22 @@ stdenv.mkDerivation rec {
 
     cp ${./mk-docker-opts.sh} $out/bin/mk-docker-opts.sh
 
-    $out/bin/kubectl completion bash > $out/share/bash-completion/completions/kubectl
-    $out/bin/kubectl completion zsh > $out/share/zsh/site-functions/_kubectl
+    for tool in kubeadm kubectl; do
+      installShellCompletion --cmd $tool \
+        --bash <($out/bin/$tool completion bash) \
+        --zsh <($out/bin/$tool completion zsh)
+    done
   '';
 
   preFixup = ''
     find $out/bin $pause/bin -type f -exec remove-references-to -t ${go} '{}' +
   '';
 
-  meta = {
+  meta = with lib; {
     description = "Production-Grade Container Scheduling and Management";
     license = licenses.asl20;
     homepage = "https://kubernetes.io";
-    maintainers = with maintainers; [johanot offline saschagrunert];
+    maintainers = with maintainers; [ johanot offline saschagrunert ];
     platforms = platforms.unix;
   };
 }