Waku scratchings (#2053)

* Add basic waku-helper functionality: read .env, perform_health_check

* Add RESTful capability to startup, example call

* Add subscribe_to_topics, debug capability

* Add publish_to_topic capability, add timestamp helpers

* Add get_new_messages_for_topic, format output nicely

* Add unsubscribe_from_topics, clean up a bit

* Tidy up

waku-helpers.sh

@@ -0,0 +1,119 @@
+# ! /usr/bin/env zsh
+#
+# Command-line utilities/helpers for WC2 development
+# Source this file with `$ source ./go.sh`.
+#
+# Requirements:
+#
+# * You have `zsh` installed
+# * Clone and build nwaku: https://is.gd/NXeAnv
+# * Add a .env file with a variable NWAKU_DIR set to your nwaku directory
+
+_err() { # write a (loud) message to stderr, if running interacively
+    [[ -o interactive ]] && tput setaf 1
+    echo "$@" 1>&2
+}
+
+# Read env vars from .env into current session
+_read_dot_env_file() {
+    [[ ! -f .env ]] && _err 'No .env file found' && return 1
+    export $(grep -v '^#' .env | xargs)
+}
+
+_DEBUG=1  # 0=on, !0=off  # nb DEBUG printing sometimes causes a superfluous error to surface (in `gnm`)
+_debugging() { (($_DEBUG == 0)); }
+
+# Conveniently refresh current shell with any changes made to this file
+_reload_waku_helpers() { source waku-helpers.sh; }
+alias rwh=_reload_waku_helpers
+
+# Start nwaku locally, connect to two known peers on localhost, enable rest{,-admin,-private}.
+# See: https://github.com/status-im/nwaku/blob/master/docs/operators/how-to/connect.md
+start_waku_node() {
+    _read_dot_env_file
+    (($+NWAKU_DIR)) || { _err 'NWAKU_DIR variable not set in .env' && return 2 }
+    binary_not_found='build/wakunode2 not found (did you build?)' # Build it: https://is.gd/NXeAnv
+    [[ ! -f $NWAKU_DIR/build/wakunode2 ]] && _err "${NWAKU_DIR}/${binary_not_found}" && return 3
+    node1='/ip4/0.0.0.0/tcp/60002/p2p/16Uiu2HAkzjwwgEAXfeGNMKFPSpc6vGBRqCdTLG5q3Gmk2v4pQw7H'
+    node2='/ip4/0.0.0.0/tcp/60003/p2p/16Uiu2HAmFBA7LGtwY5WVVikdmXVo3cKLqkmvVtuDu63fe8safeQJ'
+    $NWAKU_DIR/build/wakunode2 \
+        --staticnode:$node1 \
+        --staticnode:$node2 \
+        --rest=true --rest-admin=true --rest-private=true
+}
+alias swn=start_waku_node
+
+# N.B. nwaku features both a JSON RPC api and a RESTful one; this calls JSON RPC
+_call_json_rpc() {
+    (($# != 1)) && _err 'Usage: _call_json_rpc <payload>' && return 1
+    payload=$1
+    _debugging && echo $payload
+    # TODO Validate that localhost:8545 is an active TCP connection
+    curl -d $payload --silent --header "Content-Type: application/json" http://localhost:8545
+}
+
+# Timestamps figure prominently within the waku api, here are some helpers
+date_to_unix() { date -d "$1" +%s ; }  # `$ dtu "$(date)"` -> 1666373627
+alias dtu=date_to_unix
+unix_to_date() { date -d @$1; }  # `$ utd 1666373627`  # -> 2Fri Oct 21 10:33:47 AM PDT 2022
+alias utd=unix_to_date
+
+_make_payload() { echo "{ \"jsonrpc\":\"2.0\",\"id\":\"id\",\"method\":\"$1\", \"params\":[${@:2}] }"; }
+
+get_waku_debug_info() {
+    payload=$(_make_payload 'get_waku_v2_debug_v1_info')
+    _call_json_rpc $payload | jq
+}
+alias gwd=get_waku_debug_info
+
+# RESTful alternative to the above JSON RPC. Seems tastier to me.
+# See https://github.com/status-im/nwaku/blob/master/docs/api/v2/rest-api.md
+get_waku_debug_info2() { curl http://localhost:8645/debug/v1/info -s | jq; }
+alias gwd2=get_waku_debug_info2
+
+# Subscribe to the given topic(s) [via JSON RPC].
+# Pass multiple topics as a single arg: `subscribe_to_topic '"topic_1","topic_2"'`
+subscribe_to_topics() {
+    (($# != 1)) && _err 'Usage: subscribe_to_topic '\''"t1","t2"'\''' && return 1
+    payload=$(_make_payload 'post_waku_v2_relay_v1_subscriptions' "[$@]")
+    _call_json_rpc $payload
+}
+alias stt=subscribe_to_topics
+# eg subscribe_to_topics t3 and t4: `stt '"t3","t4"`  # note the escaping!
+
+# Publish a message to the given topic; `message` must be '{"payload:"0x...", "timestamp":1666373627}'
+# The "timestamp" param is seconds since epoch, get it with `date_to_unix $(date)`
+publish_to_topic() {
+    (($# != 2)) && _err 'Usage: publish_to_topic <topic> <payload>' && return 1
+    # TODO Validate the topic exists
+    topic=$1
+    # TODO Validate that message is enclosed {within curlies}
+    message=$2
+    payload=$(_make_payload 'post_waku_v2_relay_v1_message' \"$topic\"\, $message)
+    _call_json_rpc $payload
+}
+alias ptt=publish_to_topic
+# eg `ptt t3 '{"payload":"0x01", "timestamp":12345}'; ptt t3 '{"payload":"0x02", "timestamp":12346}'`
+
+# Read new messages for the given topic. "Cannot iterate over null" means there are no new messages.
+get_new_messages_for_topic() {
+    (($# != 1)) && _err 'Usage: get_new_messages_for_topic <topic>' && return 1
+    topic=$1
+    payload=$(_make_payload 'get_waku_v2_relay_v1_messages' \"$topic\")
+    result=$(_call_json_rpc $payload)
+    # TODO Format the error that comes back if not subscribed to the given topic
+    # TODO Fish for 'error' and print out the value if emitted
+    echo $result | jq -c '.result[]|{payload: .payload, timestamp: .timestamp}'
+}
+alias gnm=get_new_messages_for_topic
+# eg `gnm t3`
+
+# Unsubscribe from the given topic(s) [via JSON RPC].
+# Pass multiple topics as a single arg: `unsubscribe_from_topics '"topic_1","topic_2"'`
+unsubscribe_from_topics() {
+    (($# != 1)) && _err 'Usage: unsubscribe_from_topic '\''"t1","t2"'\''' && return 1
+    payload=$(_make_payload 'delete_waku_v2_relay_v1_subscriptions' "[$@]")
+    _call_json_rpc $payload
+}
+alias uft=unsubscribe_from_topics
+# eg `uft '"t3"'  # note the escaping!