Add git credential helper example (#388)

examples/git-credential-bw.sh

@@ -0,0 +1,56 @@
+#!/usr/bin/env bash
+
+# bw git-credential helper
+# Based on:
+# * https://github.com/lastpass/lastpass-cli/blob/master/contrib/examples/git-credential-lastpass
+# * https://gist.github.com/mikeboiko/58ab730afd65bca0a125bc12b6f4670d
+
+# A credential helper for git to retrieve usernames and passwords from bw.
+# For general usage, see https://git-scm.com/docs/gitcredentials.
+# Here's a quick version:
+# 1. Put this somewhere in your path.
+# 2. git config --global credential.helper bw
+
+declare -A params
+
+if [[ "$1" == "get" ]]; then
+    read -r line
+    while [ -n "$line" ]; do
+        key=${line%%=*}
+        value=${line#*=}
+        params[$key]=$value
+        read -r line
+    done
+
+    if [[ "${params['protocol']}" != "https" ]]; then
+        exit
+    fi
+
+    if [[ -z "${params["host"]}" ]]; then
+        exit
+    fi
+
+    if ! bw list items --search "asdf" > /dev/null 2>&1; then
+        echo "Please login to Bitwarden to use git credential helper" > /dev/stderr
+        exit
+    fi
+
+    id=$(bw list items --search "${params["host"]}"|jq ".[] | select(.name == \"${params["host"]}\").id" -r)
+
+    if [[ -z "$id" ]]; then
+        echo "Couldn't find item id in Bitwarden DB." > /dev/stderr
+        echo "${params}"
+        exit
+    fi
+
+    user=$(bw get username "${id}")
+    pass=$(bw get password "${id}")
+
+    if [[ -z "$user" ]] || [[ -z "$pass" ]]; then
+        echo "Couldn't find host in Bitwarden DB." > /dev/stderr
+        exit
+    fi
+
+    echo username="$user"
+    echo password="$pass"
+fi