Add multi-printer support, change API

2024-02-01 15:38:03 +01:00 · 2024-02-01 15:38:03 +01:00 · 8c8cea6eb6
parent 90344c9be6
commit 8c8cea6eb6
4 changed files with 159 additions and 44 deletions
--- a/README.md
+++ b/README.md
@ -4,29 +4,36 @@ HTTP to IPP proxy, a.k.a. HSWAW Rube Goldberg printing microservice.

 ## Usage

-TODO: This API is not stable, and is subject to change. Parameters will be added to specify printer kind, and some job attributes (like copy count, orientation, size...)
-
-```
-POST /api/1/print - Print a document
-  - body: PDF
-  - response: 200 OK if sent successfully (does not check if print *actually* succeeded, just that adding it to the print queue was successful), 400 or 500 in case of errors
-
-Debug routes:
-
-GET /api/1/printer/attributes - Prints IPP attributes
-GET /api/1/printer/jobs - Lists IPP jobs
-GET /api/1/health - Just says 200 OK
-```
+`GET /` to see available API routes

 ## Quick start

+Configuration available:
+
 ```
-PRINTSERVANT_PORT=3199 PRINTSERVANT_IPP_PRINTER_URL="ipp://printmaster.local:631/printers/DYMO_LabelWriter450" node index.js
+PRINTSERVANT_PORT - Port (default: 3199)
+PRINTSERVANT_CONFIG - JSON config, like so:
+  {
+    printers: [
+      {
+        name: 'DYMO_LabelWriter450',
+        aliases: ['dymo', 'label'],
+        ipp_url: 'ipp://$SECRET@printmaster.waw.hackerspace.pl/printers/DYMO_LabelWriter450',
+      },
+      ...
+    ]
+  }
+PRINTSERVANT_SECRET - Optional, used to substitute $SECRET in printer configs' ipp_urls
+```
+
+
+```
+PRINTSERVANT_CONFIG='{"printers":[{"name":"DYMO_LabelWriter450","aliases":["dymo"],"ipp_url":"ipp://printmaster.local:631/printers/DYMO_LabelWriter450"}]}' node index.js
 ```

 or:

 ```
 docker build -t printservant .
-docker run --env PRINTSERVANT_IPP_PRINTER_URL="ipp://printmaster.local:631/printers/DYMO_LabelWriter450" -it -p 3199:3199 printservant
+docker run --env PRINTSERVANT_CONFIG='... put config here ...' -it -p 3199:3199 printservant
 ```
--- a/index.js
+++ b/index.js
@ -1,35 +1,90 @@
+require('console-stamp')(console)
+
 const ipp = require('ipp')
 const express = require('express')
 const bodyParser = require('body-parser')

-// TODO:
-// - multiple printers
-// - take printer name, other params by query string
-const PORT = Number(process.env.PRINTSERVANT_PORT) || 3199
-const PRINTER_URL = process.env.PRINTSERVANT_IPP_PRINTER_URL
+// --- Config ---

-if (!(PORT && PRINTER_URL)) {
-  console.error("PRINTSERVANT_PORT and PRINTSERVANT_IPP_PRINTER_URL environment variables must be set")
-  process.exit(1)
+const PORT = Number(process.env.PRINTSERVANT_PORT) || 3199
+const CONFIG = JSON.parse(process.env.PRINTSERVANT_CONFIG || 'null')
+const SECRET = process.env.PRINTSERVANT_SECRET || ''
+
+if (!(PORT && CONFIG)) {
+  throw new Error("PRINTSERVANT_PORT and PRINTSERVANT_CONFIG environment variables must be set")
 }

+const printers = []
+
+for (const printerConfig of CONFIG.printers) {
+  const { name, aliases = [], ipp_url } = printerConfig
+
+  if (!(name && ipp_url)) {
+    throw new Error("Printer config must have a name and url")
+  }
+
+  if (ipp_url.includes('$SECRET') && !SECRET) {
+    throw new Error(`Printer '${name}' config has a secret in the url but no PRINTSERVANT_CONFIG was provided`)
+  }
+
+  const url = ipp_url.replace('$SECRET', SECRET)
+  const ippPrinter = ipp.Printer(url)
+
+  printers.push({ name, aliases, ippPrinter })
+}
+
+const printerMap = new Map()
+printers.forEach(printer => {
+  printerMap.set(printer.name.toLowerCase(), printer)
+  printer.aliases.forEach(alias => {
+    printerMap.set(alias.toLowerCase(), printer)
+  })
+})
+
+function getPrinter(name) {
+  return printerMap.get(name.toLowerCase())
+}
+
+// --- Debug API ---
+
 const app = express()
-const printer = ipp.Printer(PRINTER_URL)

 app.get('/', (req, res) => {
-  res.send('Hello World! I am printservant.')
+  res.send(`<pre>Hello world! API routes available:
+    - GET /
+    - GET /health
+    - GET /printers
+      - Lists all printers (names and aliases)
+    - GET /printers/:name/attributes
+      - Prints IPP attributes
+    - GET /printers/:name/jobs
+      - Prints IPP jobs
+    - POST /print?printer=:name (body: application/pdf)
+      - Prints a PDF
+      - :name - printer name or alias (case insensitive)
+      - Response: 200 OK if sent to printer successfully (not necessarily printed), 4xx/5xx otherwise
+  </pre>`)
 })

-app.get('/api/1/health', (req, res) => {
-  res.send("I'm cool, I think. I'm not sure. Thanks for asking though.")
+app.get('/health', (req, res) => {
+  res.send(`Printservant is healthy (probably)`)
 })

-function executeSimpleCommand(command, res) {
-  printer.execute(command, null, function(error, result){
-    if (error) {
-      console.log(error);
-      res.status(500)
-    } else if (result.statusCode !== 'successful-ok') {
+app.get('/printers', (req, res) => {
+  res.send(printers.map(({ name, aliases }) => ({ name, aliases })))
+})
+
+function executeSimpleCommand(printerName, command, res) {
+  const printer = getPrinter(printerName)
+  if (!printer) {
+    console.log(`Printer '${printerName}' not found`)
+    res.status(404).send(`Printer '${printerName}' not found`)
+    return
+  }
+
+  printer.ippPrinter.execute(command, null, function (error, result) {
+    if (error || result.statusCode !== 'successful-ok') {
+      console.error(error || result);
      res.status(500)
    }

@ -37,26 +92,54 @@ function executeSimpleCommand(command, res) {
  });
 }

-app.get('/api/1/printer/attributes', (req, res) => {
-  console.log('Getting printer attributes')
-  executeSimpleCommand("Get-Printer-Attributes", res)
+app.get('/printers/:name/attributes', (req, res) => {
+  const { name } = req.params
+  console.log(`Getting attributes for printer: '${name}'`)
+  executeSimpleCommand(name, "Get-Printer-Attributes", res)
 })

-app.get('/api/1/printer/jobs', (req, res) => {
-  console.log('Getting printer jobs')
-  executeSimpleCommand("Get-Jobs", res)
+app.get('/printers/:name/jobs', (req, res) => {
+  const { name } = req.params
+  console.log(`Getting jobs for printer: '${name}'`)
+  executeSimpleCommand(name, "Get-Jobs", res)
 })

-app.post('/api/1/print', bodyParser.raw({ type: '*/*' }), (req, res) => {
+// --- Print API ---
+
+app.post('/print', bodyParser.raw({ type: '*/*' }), (req, res) => {
  const { body, query } = req
-
  console.log("Received print job: ", { body, query })

-  if (!body || !body.length) {
-    res.status(400).send("No data received, please send a PDF")
+  // validate query params
+  const { printer: printerName, ...otherParams } = query
+  if (!printerName) {
+    res.status(400).send("No printer specified, pass ?printer=:name in the query params")
+    return
+  } else if (Object.keys(otherParams).length) {
+    res.status(400).send("Unknown query params, only ?printer=:name is supported")
    return
  }

+  const printer = getPrinter(printerName)
+  if (!printer) {
+    console.log(`Printer '${name}' not found`)
+    res.status(404).send(`Printer '${name}' not found`)
+    return
+  }
+
+  // validate body
+  if (!body || !body.length) {
+    res.status(400).send("No data received, please send a PDF")
+    return
+  } else if (body.subarray(0, 4).toString() !== "%PDF") {
+    res.status(415).send("Data does not look like a PDF, please send a PDF")
+    return
+  } else if (body.length > 10_000_000) {
+    res.status(413).send("Data too large (limit: 10MB), please send a smaller PDF")
+    return
+  }
+
+  // send print job
  const msg = {
    "operation-attributes-tag": {
      "document-format": "application/pdf",
@ -69,7 +152,7 @@ app.post('/api/1/print', bodyParser.raw({ type: '*/*' }), (req, res) => {
  };
  console.log("Sending print job: ", msg)

-  printer.execute("Print-Job", msg, function(error, result){
+  printer.ippPrinter.execute("Print-Job", msg, function(error, result){
    console.log({ result, error });

    if (error) {
@ -82,6 +165,8 @@ app.post('/api/1/print', bodyParser.raw({ type: '*/*' }), (req, res) => {
  });
 })

+// --- Let's goooooooo ---
+
 app.listen(PORT, () => {
  console.log(`printservant listening on port ${PORT}`)
 })
--- a/package-lock.json
+++ b/package-lock.json
@ -7,9 +7,11 @@
    "": {
      "name": "printservant",
      "version": "0.0.1",
+      "hasInstallScript": true,
      "license": "MIT",
      "dependencies": {
        "body-parser": "^1.20.2",
+        "console-stamp": "^3.1.2",
        "express": "^4.18.2",
        "ipp": "^2.0.1",
        "patch-package": "^8.0.0"
@ -178,6 +180,18 @@
      "resolved": "https://registry.npmjs.org/concat-map/-/concat-map-0.0.1.tgz",
      "integrity": "sha512-/Srv4dswyQNBfohGpz9o6Yb3Gz3SrUDqBH5rTuhGR7ahtlbYKnVxw2bCFMRljaA7EXHaXZ8wsHdodFvbkhKmqg=="
    },
+    "node_modules/console-stamp": {
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/console-stamp/-/console-stamp-3.1.2.tgz",
+      "integrity": "sha512-ab66x3NxOTxPuq71dI6gXEiw2X6ql4Le5gZz0bm7FW3FSCB00eztra/oQUuCoCGlsyKOxtULnHwphzMrRtzMBg==",
+      "dependencies": {
+        "chalk": "^4.1.2",
+        "dateformat": "^4.6.3"
+      },
+      "engines": {
+        "node": ">=12"
+      }
+    },
    "node_modules/content-disposition": {
      "version": "0.5.4",
      "resolved": "https://registry.npmjs.org/content-disposition/-/content-disposition-0.5.4.tgz",
@ -223,6 +237,14 @@
        "node": ">= 8"
      }
    },
+    "node_modules/dateformat": {
+      "version": "4.6.3",
+      "resolved": "https://registry.npmjs.org/dateformat/-/dateformat-4.6.3.tgz",
+      "integrity": "sha512-2P0p0pFGzHS5EMnhdxQi7aJN+iMheud0UhG4dlE1DLAlvL8JHjJJTX/CSm4JXwV0Ka5nGk3zC5mcb5bUQUxxMA==",
+      "engines": {
+        "node": "*"
+      }
+    },
    "node_modules/debug": {
      "version": "2.6.9",
      "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
--- a/package.json
+++ b/package.json
@ -11,6 +11,7 @@
  "license": "MIT",
  "dependencies": {
    "body-parser": "^1.20.2",
+    "console-stamp": "^3.1.2",
    "express": "^4.18.2",
    "ipp": "^2.0.1",
    "patch-package": "^8.0.0"