Added nginx_ua_block_pleroma_rejects.

Generates a User-Agent blocklist for nginx from the rejected domains in
mrf_simple.

nginx_ua_block_pleroma_rejects.sh

@@ -0,0 +1,58 @@
+#!/bin/zsh
+# Generates an nginx-map of User-Agents to block from the rejected domains in
+# mrf_simple.
+# Save the output to a file and include it in an nginx configuration file. Then
+# add `if ($blockedagent) { return 403; }` to your server blocks.
+
+# Version: 2019-08-17_1
+
+
+function get_domains()          # Outputs domains, separated by newline.
+{
+    local instance="${1}"
+    local nodeinfo=$(curl -s "https://${instance}/nodeinfo/2.1.json")
+    local domains_json=$(jq -c '.metadata.federation.mrf_simple.reject' \
+                            <<<"${nodeinfo}")
+
+    sed -e 's/\[//' -e 's/\]//' -e 's/"//g' -e 's/,/\n/g' <<<"${domains_json}"
+}
+
+function print_entry()
+{
+    local domain="${1}"
+    # Filter out wildcard domains.
+    if ! [[ "${domain}" =~ "\*" ]]; then
+        domain=$(sed 's/\./\\./g' <<<${domain})
+        echo "    ~* ${domain} 1;"
+    fi
+}
+
+function main()
+{
+    local instance="${1}"
+
+    if [[ -z "${instance}" ]]; then
+        echo "Usage: ${ZSH_ARGZERO} instance" >&2
+        echo "       ${ZSH_ARGZERO} instance > /etc/nginx/useragents_fedi.rules"
+        return 1
+    fi
+    if ! command -v curl > /dev/null; then
+        echo "Error: curl not found. Please install it." >&2
+        return 2
+    fi
+    if ! command -v jq > /dev/null; then
+        echo "Error: jq not found. Please install it." >&2
+        return 2
+    fi
+
+    echo 'map $http_user_agent $blockedagent {'
+    echo "    default 0;"
+
+    for domain in $(get_domains "${instance}"); do
+        print_entry "${domain}"
+    done
+
+    echo "}"
+}
+
+main "${1}"