Created
December 5, 2022 05:10
-
-
Save dancingfrog/b9527bf40dde86774b95eb64ec11ddb3 to your computer and use it in GitHub Desktop.
Plumber with proxy to Shiny (toy) app running in background cluster
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| library("future") | |
| library("httr") | |
| library("magrittr") | |
| library("plumber") | |
| library("shiny") | |
| library("uuid") | |
| library("websocket") | |
| library("R6") | |
| shiny_port <- 5174 | |
| # Define UI for app that draws a histogram ---- | |
| ui <- shiny::fluidPage( | |
| # App title ---- | |
| shiny::titlePanel("Hello Shiny!"), | |
| # Sidebar layout with input and output definitions ---- | |
| shiny::sidebarLayout( | |
| # Sidebar panel for inputs ---- | |
| shiny::sidebarPanel( | |
| # Input: Slider for the number of bins ---- | |
| shiny::sliderInput(inputId = "bins", | |
| label = "Number of bins:", | |
| min = 1, | |
| max = 50, | |
| value = 30) | |
| ), | |
| # Main panel for displaying outputs ---- | |
| shiny::mainPanel( | |
| # Output: Histogram ---- | |
| shiny::plotOutput(outputId = "distPlot") | |
| ) | |
| ) | |
| ) | |
| # Define server logic required to draw a histogram ---- | |
| server <- function(input, output) { | |
| # Histogram of the Old Faithful Geyser Data ---- | |
| # with requested number of bins | |
| # This expression that generates a histogram is wrapped in a call | |
| # to renderPlot to indicate that: | |
| # | |
| # 1. It is "reactive" and therefore should be automatically | |
| # re-executed when inputs (input$bins) change | |
| # 2. Its output type is a plot | |
| output$distPlot <- shiny::renderPlot({ | |
| x <- faithful$waiting | |
| bins <- seq(min(x), max(x), length.out = input$bins + 1) | |
| hist(x, breaks = bins, col = "#007bc2", border = "white", | |
| xlab = "Waiting time to next eruption (in mins)", | |
| main = "Histogram of waiting times") | |
| }) | |
| } | |
| future_cluster <- future::makeClusterPSOCK(1) #future::availableCores()) | |
| parallelly::autoStopCluster(future_cluster) | |
| for (cl_idx in seq_along(future_cluster)) { | |
| parallel:::sendCall(future_cluster[[cl_idx]], fun = Sys.getpid, args = list()) | |
| cl_pid <- parallel:::recvResult(future_cluster[[cl_idx]]) | |
| attr(future_cluster[[cl_idx]]$host, "pid") <- cl_pid | |
| } | |
| future::plan(future::cluster, workers = future_cluster) | |
| shiny_app_future <- future::future({ | |
| shiny_app <- shiny::runApp( | |
| app = shiny::shinyApp(ui = ui, server = server), | |
| host = "0.0.0.0", | |
| port = shiny_port, | |
| launch.browser = FALSE | |
| ) | |
| return(NULL) | |
| }) | |
| # From https://gabrielcp.medium.com/going-real-time-in-r-plumber-with-websockets-93547c767412 | |
| PlumberWebSocket <- R6::R6Class( | |
| "PlumberWebSocket", | |
| inherit = plumber::Plumber, | |
| public = list( | |
| onWSOpen = function(ws) { | |
| if (is.function(private$ws_open)) { | |
| private$ws_open(ws) | |
| } | |
| invisible(self) | |
| }, | |
| websocket = function(open = NULL) { | |
| if (!is.null(open)) stopifnot(is.function(open)) | |
| private$ws_open <- open | |
| } | |
| ), | |
| private = list( | |
| ws_open = NULL | |
| ) | |
| ) | |
| plumbr <- PlumberWebSocket$new() | |
| plumbr$onWSOpen() | |
| clients <- list() | |
| addClient <- function(ws_client, message) { | |
| ws_client$request$uuid <- UUIDgenerate() | |
| print(clients) | |
| for(client in clients) { | |
| print(clients) | |
| print("\n") | |
| } | |
| print(ws_client$request$uuid %in% names(clients)) | |
| if (!(ws_client$request$uuid %in% names(clients))) { | |
| clients[[ws_client$request$uuid]] <<- ws_client #<<- modifies clients globally | |
| ws_client$onClose(function() { | |
| removeClient(ws_client$request$uuid) | |
| }) | |
| ws_client$request$ws_shiny <- websocket::WebSocket$new(paste0("ws://127.0.0.1", ":", shiny_port, "/")) | |
| ws_client$request$ws_shiny$connect() | |
| ws_client$request$ws_shiny$onMessage(function(event) { | |
| print("Relay Shiny server event message to websocket client...") | |
| ws_client$send(event$data) | |
| print(event) | |
| }) | |
| } | |
| return(clients) | |
| } | |
| removeClient <- function(uuid) { | |
| clients[[uuid]] <<- NULL | |
| } | |
| handleWebsockets <- function(pr) { | |
| pr$websocket( | |
| function (ws_client) { | |
| addClient(ws_client) | |
| print("New user connected!") | |
| ws_client$onMessage(function(binary, message) { | |
| if ("ws_shiny" %in% names(ws_client$request)) { | |
| print("Relay websocket message to Shiny server...") | |
| Sys.sleep(1) | |
| ws_client$request$ws_shiny$send(as.character(message)) | |
| print(message) | |
| } | |
| }) | |
| } | |
| ) | |
| pr | |
| } | |
| plumbr %>% | |
| handleWebsockets %>% | |
| plumber::pr_filter("myFilter", function(req){ | |
| cat(as.character(Sys.time()), "-", | |
| req$REQUEST_METHOD, req$PATH_INFO, "-", | |
| req$HTTP_USER_AGENT, "@", req$REMOTE_ADDR, "\n") | |
| plumber::forward() | |
| }) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/", function (req, res) { | |
| # "<html> | |
| # <h1>Hello, World!</h1> | |
| # </html>" | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }, serializer = plumber::serializer_html()) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/<file>", function (file, req, res) { | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| cat(paste0(file, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/<path1>/<file>.css", function (path1, file, req, res) { | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| cat(paste0(path1, "/", file, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }, serializer = plumber::serializer_text( | |
| serialize_fn = as.character, | |
| type = "text/css" | |
| )) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/<path1>/<file>.js", function (path1, file, req, res) { | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| cat(paste0(path1, "/", file, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }, serializer = plumber::serializer_text( | |
| serialize_fn = as.character, | |
| type = "application/javascript" | |
| )) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/<path1>/<file>", function (path1, file, req, res) { | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| cat(paste0(path1, "/", file, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/<path1>/<path2>/<file>.css", function (path1, path2, file, req, res) { | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| cat(paste0(path1, "/", path2, "/", file, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }, serializer = plumber::serializer_text( | |
| serialize_fn = as.character, | |
| type = "text/css" | |
| )) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/<path1>/<path2>/<file>.js", function (path1, path2, file, req, res) { | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| cat(paste0(path1, "/", path2, "/", file, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }, serializer = plumber::serializer_text( | |
| serialize_fn = as.character, | |
| type = "application/javascript" | |
| )) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/<path1>/<path2>/<file>", function (path1, path2, file, req, res) { | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| cat(paste0(path1, "/", path2, "/", file, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/<path1>/<path2>/<path3>/<file>.css", function (path1, path2, path3, file, req, res) { | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| cat(paste0(path1, "/", path2, "/", path3, "/", file, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }, serializer = plumber::serializer_text( | |
| serialize_fn = as.character, | |
| type = "text/css" | |
| )) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/<path1>/<path2>/<path3>/<file>.js", function (path1, path2, path3, file, req, res) { | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| cat(paste0(path1, "/", path2, "/", path3, "/", file, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }, serializer = plumber::serializer_text( | |
| serialize_fn = as.character, | |
| type = "application/javascript" | |
| )) %>% | |
| plumber::pr_handle(c("GET", "POST"), "/<path1>/<path2>/<path3>/<file>", function (path1, path2, path3, file, req, res) { | |
| cat(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO, "\n")) | |
| cat(paste0(path1, "/", path2, "/", path3, "/", file, "\n")) | |
| httr_target <- httr::GET(paste0("http://", req$REMOTE_ADDR, ":", shiny_port, req$PATH_INFO)); | |
| httr_result <- httr::content(httr_target, "text") | |
| # print(httr_result) | |
| httr_result | |
| }) %>% | |
| plumber::pr_hook("exit", function(){ | |
| print("Stop the future cluster (bg workers)...") | |
| tryCatch( | |
| { | |
| future_host <- shiny_app_future$workers[[shiny_app_future$node]]$host | |
| print(future_host) | |
| pid <- attr(future_host, "pid") | |
| print(pid) | |
| tools::pskill(pid) | |
| }, | |
| finally = function () { | |
| parallel::stopCluster(future_cluster) | |
| } | |
| ) | |
| print("Bye bye!") | |
| }) %>% | |
| plumber::pr_run( | |
| host = "0.0.0.0", | |
| port = 3000 | |
| ) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment