Better CLI messages, better comments, cleaner code.

Karchnu 2020-11-04 02:59:42 +01:00
parent e2bb0b3122
commit d9c53342dc
2 changed files with 80 additions and 48 deletions

.gitignore vendored
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@ -2,6 +2,8 @@ shard.lock

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@ -67,17 +67,33 @@ module IPCd
def to_s(io : IO)
io << "ipcd\n"
io << @rules.to_s + "\n" + @redirections.to_s
# The client asks to ipcd to open a connection to a service
# the service name is used unless there is a redirection that is provided to the client through
# a IPC_NETWORK environment variable
# This environment variable is sent from the client to ipcd, that's what is parsed here
# Client => ipcd => Service.
# ipcd creates a network connection to the remote host,
# then provides a file descriptor to the client.
# Besides ipcd configuration, the client shares its IPC_NETWORK
# environment variable to ipcd to understand how to contact the service.
# parse_lookup_payload extract the right service URI to use from the IPC_NETWORK content
# sent by the client in the form:
# `requested-service-name;service1 uri;service2 uri;...` etc.
# IPC_NETWORK environment variable contains pairs of URIs (redirections).
# Format: "requested-service new-URI"
# Example: "pong tcp://"
# The URI indicates the scheme, the domain (or directly the IP address) and the port
# to contact the remote service. The path indicates the remote service to use.
# Several redirections can be put into the IPC_NETWORK variable, using a semi-colon.
# Example: "pong tcp://;auth tls://"
# ipcd prioritises IPC_NETWORK over its own configuration for redirections.
# This environment variable is sent from the client to ipcd, that's what is parsed here.
# parse_lookup_payload extracts the right service URI to use from the message sent by
# a client, containing the service to contact and the IPC_NETWORK content.
# Format: "requested-service;IPC_NETWORK content"
# Example: "pong;pong tcp://"
def self.parse_lookup_payload (payload : String) : URI
items = payload.split (";")
requested_service_name = items.delete_at(0).chomp()
@ -85,30 +101,27 @@ module IPCd
services_redirections = {} of String => URI
# from each item (separated by a semicolon), get the service name and the new uri to use
# format: `service-name uri;service-name uri`
# uri can be:
# Format: "service-name URI;service-name URI"
# URI can be:
# * distant service (with protocol to use):
# * local service: "local:newpong" or simply "newpong"
items.each do |item|
x = /([^ ]+) ([^ ]+)/.match(item)
unless x.nil?
service, newuri = x.captures()
if service.nil?
elsif newuri.nil?
case item
when /(?<origin>[^ ]+) +(?<destination_uri>[^ ]+)/
origin, destination_uri = $~["origin"], $~["destination_uri"]
uri = URI.parse destination_uri
if uri.scheme.nil?
uri = URI.parse "unix:///#{destination_uri}"
Baguette::Log.debug "service: #{service} redirection uri: #{newuri}"
uri = URI.parse newuri
services_redirections[service] = uri
services_redirections[origin] = uri
Baguette::Log.error "cannot understand configuration #{item}"
services_redirections.each do |k, v|
Baguette::Log.debug "possible redirection (from env. var.): service: #{k} uri: #{v}"
if k == requested_service_name "prefered redirection (from IPC_NETWORK): #{k} => #{v}"
requested_service = v
@ -117,50 +130,67 @@ module IPCd
def service_lookup (message : IPC::Message, fd : Int32)
payload = message.payload
def service_lookup (message : IPC::Message, client_fd : Int32)
requested_service = IPCd::Service.parse_lookup_payload
requested_service = IPCd::Service.parse_lookup_payload payload
# Now, we want to get the service used for transport.
# Network services used to carry libipc messages are named based on the scheme.
# Examples: tcp, udp, ws, etc.
network_service_name = requested_service.scheme
scheme = requested_service.scheme
if scheme.nil?
raise "no SCHEME in redirection"
if network_service_name.nil?
raise "no scheme"
service_name = scheme
if scheme == "unix"
# scheme == unix => simple redirection
# the URI is "unix:///service" so the path is "/service"
# first, remove its slash prefix
service_name = requested_service.path.lchop
# In case of "unix", then it's a simple redirection to do, no network required.
if requested_service.scheme == "unix"
# The URI is "unix:///service" so the path is "/service".
# Service to contact is simply the path minus the slash.
network_service_name = requested_service.path.lchop
Baguette::Log.debug "connecting to #{network_service_name}"
service = begin network_service_name
rescue e
# Better raise message.
raise "cannot contact #{network_service_name}"
# Will probably never happen in practice.
if service.fd.nil?
raise "no fd for #{network_service_name}"
end "service name: #{service_name}"
service = service_name
service_fd = service.fd.not_nil!
# TODO: for remote services, we have to connect to communication service
# these communication services need an URI to work on
# The protocol:
# ipcd sends an URI to the communication service, which responds with a "OK" message
if scheme != "unix"
service.send service_fd, 1.to_u8, "#{requested_service.to_s}\n"
# A network service is necessary for remote communications, and it requires an URI.
# TODO: protocol between ipcd and network services.
# The (draft) protocol:
# - ipcd sends an URI to the network service
# - network service responds with a "OK" message
if requested_service.scheme != "unix"
service.send service_fd, 1.to_u8, requested_service.to_s
response =
payload = response.payload
if payload.chomp != "OK"
raise "service #{service_name} response was #{payload.chomp}"
raise "service #{network_service_name} response was #{payload.chomp}"
# Then we provide the file descriptor to the client
r = LibIPC.ipc_provide_fd(fd, service_fd)
Baguette::Log.debug "providing the fd from #{network_service_name} to the client #{client_fd}"
# Provide the file descriptor to the client.
r = LibIPC.ipc_provide_fd(client_fd, service_fd)
if r.error_code != 0
m = r.error_message.to_slice
raise "cannot send the file descriptor of the requested service: #{m}"
# finally, the service should be closed in ipcd
Baguette::Log.debug "everything went well, closing the service fd"
# Finally, the service should be closed in ipcd.