zsh autocompletion and updating docs

cmd/kops/completion.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"io"
 
+	"bytes"
 	"github.com/spf13/cobra"
 	"k8s.io/kops/cmd/kops/util"
 )
@@ -40,27 +41,69 @@ const boilerPlate = `
 # limitations under the License.
 `
 
+var (
+	completion_shells = map[string]func(out io.Writer, cmd *cobra.Command) error{
+		"bash": runCompletionBash,
+		"zsh":  runCompletionZsh,
+	}
+)
+
 type CompletionOptions struct {
 	Shell string
 }
 
 var (
-	longDescription = `Output shell completion code for the given shell (bash).
+	longDescription = `
+
+Output shell completion code for the specified shell (bash or zsh).
+The shell code must be evalutated to provide interactive
+completion of kops commands.  This can be done by sourcing it from
+the .bash_profile.
 
-This command prints shell code which must be evaluation to provide interactive
-completion of kops commands.`
+Note: this requires the bash-completion framework, which is not installed
+by default on Mac.  This can be installed by using homebrew:
 
+	$ brew install bash-completion
+
+Once installed, bash_completion must be evaluated.  This can be done by adding the
+following line to the .bash_profile
+
+	$ source $(brew --prefix)/etc/bash_completion
+
+Note for zsh users: [1] zsh completions are only supported in versions of zsh >= 5.2`
 	example = `
-# load in the kops completion code for bash (depends on the bash-completion framework).
-source <(kops completion bash)`
+
+# Install bash completion on a Mac using homebrew
+
+$ brew install bash-completion
+
+$ printf "
+# Bash completion support
+source $(brew --prefix)/etc/bash_completion
+" >> $HOME/.bash_profile
+	source $HOME/.bash_profile
+	# Load the kops completion code for bash into the current shell
+	source <(kops completion bash)
+	# Write bash completion code to a file and source if from .bash_profile
+	kops completion bash > ~/.kops/completion.bash.inc
+	printf "
+
+# kops shell completion
+'$HOME/.kops/completion.bash.inc'
+" >> $HOME/.bash_profile
+
+$ source $HOME/.bash_profile
+
+# Load the kops completion code for zsh[1] into the current shell
+source <(kops completion zsh)`
 )
 
 func NewCmdCompletion(f *util.Factory, out io.Writer) *cobra.Command {
 	options := &CompletionOptions{}
 
 	cmd := &cobra.Command{
 		Use:     "completion",
-		Short:   "Output shell completion code for the given shell (bash).",
+		Short:   "Output shell completion code for the given shell (bash or zsh).",
 		Long:    longDescription,
 		Example: example,
 		Run: func(cmd *cobra.Command, args []string) {
@@ -78,6 +121,7 @@ func NewCmdCompletion(f *util.Factory, out io.Writer) *cobra.Command {
 
 func RunCompletion(f *util.Factory, cmd *cobra.Command, args []string, out io.Writer, c *CompletionOptions) error {
 	if len(args) != 0 {
+
 		if c.Shell != "" {
 			return fmt.Errorf("cannot specify shell both as a flag and a positional argument")
 		}
@@ -88,19 +132,166 @@ func RunCompletion(f *util.Factory, cmd *cobra.Command, args []string, out io.Wr
 		return fmt.Errorf("shell is required")
 	}
 
-	if c.Shell != "bash" {
-		return fmt.Errorf("only bash shell is supported for kops completion")
+	run, found := completion_shells[args[0]]
+	if !found {
+		return fmt.Errorf("Unsupported shell type %q.", args[0])
 	}
 
-	_, err := out.Write([]byte(boilerPlate))
-	if err != nil {
+	if _, err := out.Write([]byte(boilerPlate)); err != nil {
 		return err
 	}
 
-	err = rootCommand.cobraCommand.GenBashCompletion(out)
-	if err != nil {
-		return err
-	}
+	return run(out, cmd.Parent())
+}
+
+func runCompletionBash(out io.Writer, cmd *cobra.Command) error {
+	return cmd.GenBashCompletion(out)
+}
 
+func runCompletionZsh(out io.Writer, cmd *cobra.Command) error {
+	zsh_initialization := `
+__kops_bash_source() {
+	alias shopt=':'
+	alias _expand=_bash_expand
+	alias _complete=_bash_comp
+	emulate -L sh
+	setopt kshglob noshglob braceexpand
+	source "$@"
+}
+__kops_type() {
+	# -t is not supported by zsh
+	if [ "$1" == "-t" ]; then
+		shift
+		# fake Bash 4 to disable "complete -o nospace". Instead
+		# "compopt +-o nospace" is used in the code to toggle trailing
+		# spaces. We don't support that, but leave trailing spaces on
+		# all the time
+		if [ "$1" = "__kops_compopt" ]; then
+			echo builtin
+			return 0
+		fi
+	fi
+	type "$@"
+}
+__kops_compgen() {
+	local completions w
+	completions=( $(compgen "$@") ) || return $?
+	# filter by given word as prefix
+	while [[ "$1" = -* && "$1" != -- ]]; do
+		shift
+		shift
+	done
+	if [[ "$1" == -- ]]; then
+		shift
+	fi
+	for w in "${completions[@]}"; do
+		if [[ "${w}" = "$1"* ]]; then
+			echo "${w}"
+		fi
+	done
+}
+__kops_compopt() {
+	true # don't do anything. Not supported by bashcompinit in zsh
+}
+__kops_declare() {
+	if [ "$1" == "-F" ]; then
+		whence -w "$@"
+	else
+		builtin declare "$@"
+	fi
+}
+__kops_ltrim_colon_completions()
+{
+	if [[ "$1" == *:* && "$COMP_WORDBREAKS" == *:* ]]; then
+		# Remove colon-word prefix from COMPREPLY items
+		local colon_word=${1%${1##*:}}
+		local i=${#COMPREPLY[*]}
+		while [[ $((--i)) -ge 0 ]]; do
+			COMPREPLY[$i]=${COMPREPLY[$i]#"$colon_word"}
+		done
+	fi
+}
+__kops_get_comp_words_by_ref() {
+	cur="${COMP_WORDS[COMP_CWORD]}"
+	prev="${COMP_WORDS[${COMP_CWORD}-1]}"
+	words=("${COMP_WORDS[@]}")
+	cword=("${COMP_CWORD[@]}")
+}
+__kops_filedir() {
+	local RET OLD_IFS w qw
+	__debug "_filedir $@ cur=$cur"
+	if [[ "$1" = \~* ]]; then
+		# somehow does not work. Maybe, zsh does not call this at all
+		eval echo "$1"
+		return 0
+	fi
+	OLD_IFS="$IFS"
+	IFS=$'\n'
+	if [ "$1" = "-d" ]; then
+		shift
+		RET=( $(compgen -d) )
+	else
+		RET=( $(compgen -f) )
+	fi
+	IFS="$OLD_IFS"
+	IFS="," __debug "RET=${RET[@]} len=${#RET[@]}"
+	for w in ${RET[@]}; do
+		if [[ ! "${w}" = "${cur}"* ]]; then
+			continue
+		fi
+		if eval "[[ \"\${w}\" = *.$1 || -d \"\${w}\" ]]"; then
+			qw="$(__kops_quote "${w}")"
+			if [ -d "${w}" ]; then
+				COMPREPLY+=("${qw}/")
+			else
+				COMPREPLY+=("${qw}")
+			fi
+		fi
+	done
+}
+__kops_quote() {
+    if [[ $1 == \'* || $1 == \"* ]]; then
+        # Leave out first character
+        printf %q "${1:1}"
+    else
+    	printf %q "$1"
+    fi
+}
+autoload -U +X bashcompinit && bashcompinit
+# use word boundary patterns for BSD or GNU sed
+LWORD='[[:<:]]'
+RWORD='[[:>:]]'
+if sed --help 2>&1 | grep -q GNU; then
+	LWORD='\<'
+	RWORD='\>'
+fi
+__kops_convert_bash_to_zsh() {
+	sed \
+	-e 's/declare -F/whence -w/' \
+	-e 's/_get_comp_words_by_ref "\$@"/_get_comp_words_by_ref "\$*"/' \
+	-e 's/local \([a-zA-Z0-9_]*\)=/local \1; \1=/' \
+	-e 's/flags+=("\(--.*\)=")/flags+=("\1"); two_word_flags+=("\1")/' \
+	-e 's/must_have_one_flag+=("\(--.*\)=")/must_have_one_flag+=("\1")/' \
+	-e "s/${LWORD}_filedir${RWORD}/__kops_filedir/g" \
+	-e "s/${LWORD}_get_comp_words_by_ref${RWORD}/__kops_get_comp_words_by_ref/g" \
+	-e "s/${LWORD}__ltrim_colon_completions${RWORD}/__kops_ltrim_colon_completions/g" \
+	-e "s/${LWORD}compgen${RWORD}/__kops_compgen/g" \
+	-e "s/${LWORD}compopt${RWORD}/__kops_compopt/g" \
+	-e "s/${LWORD}declare${RWORD}/__kops_declare/g" \
+	-e "s/\\\$(type${RWORD}/\$(__kops_type/g" \
+	<<'BASH_COMPLETION_EOF'
+`
+	out.Write([]byte(zsh_initialization))
+
+	buf := new(bytes.Buffer)
+	cmd.GenBashCompletion(buf)
+	out.Write(buf.Bytes())
+
+	zsh_tail := `
+BASH_COMPLETION_EOF
+}
+__kops_bash_source <(__kops_convert_bash_to_zsh)
+`
+	out.Write([]byte(zsh_tail))
 	return nil
 }

docs/cli/kops_completion.md

@@ -1,14 +1,28 @@
 ## kops completion
 
-Output shell completion code for the given shell (bash)
+Output shell completion code for the given shell (bash or zsh).
 
 ### Synopsis
 
 
-Output shell completion code for the given shell (bash).
 
-This command prints shell code which must be evaluation to provide interactive
-completion of kops commands.
+
+Output shell completion code for the specified shell (bash or zsh).
+The shell code must be evalutated to provide interactive
+completion of kops commands.  This can be done by sourcing it from
+the .bash_profile.
+
+Note: this requires the bash-completion framework, which is not installed
+by default on Mac.  This can be installed by using homebrew:
+
+	$ brew install bash-completion
+
+Once installed, bash_completion must be evaluated.  This can be done by adding the
+following line to the .bash_profile
+
+	$ source $(brew --prefix)/etc/bash_completion
+
+Note for zsh users: [1] zsh completions are only supported in versions of zsh >= 5.2
 
 ```
 kops completion
@@ -18,8 +32,30 @@ kops completion
 
 ```
 
-# load in the kops completion code for bash (depends on the bash-completion framework).
-source <(kops completion bash)
+
+# Install bash completion on a Mac using homebrew
+
+$ brew install bash-completion
+
+$ printf "
+# Bash completion support
+source $(brew --prefix)/etc/bash_completion
+" >> $HOME/.bash_profile
+	source $HOME/.bash_profile
+	# Load the kops completion code for bash into the current shell
+	source <(kops completion bash)
+	# Write bash completion code to a file and source if from .bash_profile
+	kops completion bash > ~/.kops/completion.bash.inc
+	printf "
+
+# kops shell completion
+'$HOME/.kops/completion.bash.inc'
+" >> $HOME/.bash_profile
+
+$ source $HOME/.bash_profile
+
+# Load the kops completion code for zsh[1] into the current shell
+source <(kops completion zsh)
 ```
 
 ### Options