Add http_client

README.md

@@ -241,6 +241,63 @@ Examples:
 
 ---
 
+## http_client
+
+The inverse of `http-driver`.
+
+### Caveats
+- HTTPS is assumed unless the request is to port 80.
+- If the request or response sets `Content-Type` to `application/json` or `…/preserves`
+  the body will be a parsed Preserves value.
+- No cache support.
+- Internal errors propagate using a `400 Internal client error` response.
+
+Sample Syndicate server script:
+```
+# A top-level dataspace
+let ?ds = dataspace
+
+# A dataspace for handling the HTTP response.
+let ?response = dataspace
+$response [
+  ?? <done { "code": "EUR" "exchange_middle": ?middle } > [
+    $ds <exchange EUR RSD $middle>
+  ]
+]
+
+$ds [
+  <request
+      # Request Euro to Dinar exchange rate.
+      <http-request 0 "kurs.resenje.org" 443
+        get ["api" "v1" "currencies" "eur" "rates" "today"]
+        {Content-Type: "application/json"} {} #f
+      >
+    $response
+  >
+
+  # Log all assertions.
+  ? ?any [
+    $log ! <log "-" { assertion: $any }>
+  ]
+]
+
+? <service-object <daemon http-client> ?cap> [
+  $cap <http-client {
+    dataspace: $ds
+  }>
+]
+
+<require-service <daemon http-client>>
+
+? <built http-client ?path ?sum> [
+  <daemon http-client {
+    argv: [ "/bin/http_client" ]
+    clearEnv: #t
+    protocol: application/syndicate
+  }>
+]
+```
+
 ## mintsturdyref
 
 A utility for minting [Sturdyrefs](https://synit.org/book/operation/builtin/gatekeeper.html#sturdyrefs).

config.prs

@@ -26,6 +26,10 @@ UnixAddress = <unix @path string>.
 
 SocketAddress = TcpAddress / UnixAddress .
 
+HttpClientArguments = <http-client {
+  dataspace: #:any
+}>.
+
 HttpDriverArguments = <http-driver {
   dataspace: #:any
 }>.

src/http_client.nim

@@ -0,0 +1,91 @@
+# SPDX-FileCopyrightText: ☭ Emery Hemingway
+# SPDX-License-Identifier: Unlicense
+
+# TODO: write a TAPS HTTP client. Figure out how to externalise TLS.
+
+import
+  std/[httpclient, options, streams, strutils, tables, uri],
+  pkg/taps,
+  pkg/preserves,
+  pkg/syndicate, pkg/syndicate/protocols/http,
+  ./schema/config
+
+proc url(req: HttpRequest): Uri =
+  result.scheme = if req.port == 80: "http" else: "https"
+  result.hostname = req.host.present
+  result.port = $req.port
+  for i, p in req.path:
+    if 0 < i: result.path.add '/'
+    result.path.add p.encodeUrl
+  for key, vals in req.query:
+    if result.query.len > 0:
+      result.query.add '&'
+    result.query.add key.string.encodeUrl
+    for i, val in vals:
+      if i == 0: result.query.add '='
+      elif i < vals.high: result.query.add ','
+      result.query.add val.string.encodeUrl
+
+proc bodyString(req: HttpRequest): string =
+  if req.body.orKind == RequestBodyKind.present:
+    return cast[string](req.body.present)
+
+proc spawnHttpClient*(turn: Turn; root: Cap): Actor {.discardable.} =
+
+  during(turn, root, ?:HttpClientArguments) do (ds: Cap):
+    spawn("http-client", turn) do (turn: Turn):
+      during(turn, ds, HttpContext.grabType) do (ctx: HttpContext):
+        let peer = ctx.res.unembed(Cap).get
+        var client = newHttpClient()
+        try:
+          var
+            headers = newHttpHeaders()
+            contentType = ""
+          for key, val in ctx.req.headers:
+            if key == Symbol"Content-Type":
+              contentType = val
+            client.headers[key.string] = val
+          let stdRes = client.request(
+              ctx.req.url,
+              ctx.req.method.string.toUpper,
+              ctx.req.bodyString, headers
+            )
+          var resp = HttpResponse(orKind: HttpResponseKind.status)
+          resp.status.code = stdRes.status[0 .. 2].parseInt
+          resp.status.message = stdRes.status[3 .. ^1]
+          message(turn, peer, resp)
+          resp = HttpResponse(orKind: HttpResponseKind.header)
+          for key, val in stdRes.headers:
+            if key == "Content-Type":
+              contentType = val
+            resp.header.name = key.Symbol
+            resp.header.value = val
+          message(turn, peer, resp)
+          case contentType
+          of "application/json", "text/preserves":
+            message(turn, peer,
+                initRecord("done", stdRes.bodyStream.readAll.parsePreserves))
+          of "application/preserves":
+            message(turn, peer,
+                initRecord("done", stdRes.bodyStream.decodePreserves))
+          else:
+            resp = HttpResponse(orKind: HttpResponseKind.done)
+            resp.done.chunk.string = stdRes.bodyStream.readAll()
+            message(turn, peer, resp)
+        except CatchableError as err:
+          var resp = HttpResponse(orKind: HttpResponseKind.status)
+          resp.status.code = 400
+          resp.status.message = "Internal client error"
+          message(turn, peer, resp)
+          resp = HttpResponse(orKind: HttpResponseKind.done)
+          resp.done.chunk.string = err.msg
+          message(turn, peer, resp)
+        client.close()
+      do:
+        client.close()
+
+when isMainModule:
+  import syndicate/relays
+  runActor("main") do (turn: Turn):
+    resolveEnvironment(turn) do (turn: Turn; ds: Cap):
+      spawnHttpClient(turn, ds)

src/http_client.nim.cfg

@@ -0,0 +1 @@
+define:ssl

src/schema/config.nim

@@ -10,6 +10,12 @@ type
   WebsocketArguments* {.preservesRecord: "websocket".} = object
     `field0`*: WebsocketArgumentsField0
 
+  HttpClientArgumentsField0* {.preservesDictionary.} = object
+    `dataspace`* {.preservesEmbedded.}: EmbeddedRef
+
+  HttpClientArguments* {.preservesRecord: "http-client".} = object
+    `field0`*: HttpClientArgumentsField0
+
   JsonTranslatorArgumentsField0* {.preservesDictionary.} = object
     `argv`*: seq[string]
     `dataspace`* {.preservesEmbedded.}: EmbeddedRef
@@ -117,7 +123,8 @@ type
     `host`*: string
     `port`*: BiggestInt
 
-proc `$`*(x: WebsocketArguments | JsonTranslatorArguments | SocketAddress |
+proc `$`*(x: WebsocketArguments | HttpClientArguments | JsonTranslatorArguments |
+    SocketAddress |
     Base64DecoderArguments |
     JsonTranslatorConnected |
     JsonSocketTranslatorArguments |
@@ -136,7 +143,9 @@ proc `$`*(x: WebsocketArguments | JsonTranslatorArguments | SocketAddress |
     Tcp): string =
   `$`(toPreserves(x))
 
-proc encode*(x: WebsocketArguments | JsonTranslatorArguments | SocketAddress |
+proc encode*(x: WebsocketArguments | HttpClientArguments |
+    JsonTranslatorArguments |
+    SocketAddress |
     Base64DecoderArguments |
     JsonTranslatorConnected |
     JsonSocketTranslatorArguments |

syndicate_utils.nimble

@@ -1,11 +1,11 @@
 # Package
 
-version = "20240430"
+version = "20240509"
 author        = "Emery Hemingway"
 description   = "Utilites for Syndicated Actors and Synit"
 license       = "unlicense"
 srcDir        = "src"
-bin           = @["mintsturdyref", "mount_actor", "msg", "postgre_actor", "preserve_process_environment", "rofi_script_actor", "sqlite_actor", "syndesizer", "syndump", "xslt_actor"]
+bin           = @["http_client", "mintsturdyref", "mount_actor", "msg", "postgre_actor", "preserve_process_environment", "rofi_script_actor", "sqlite_actor", "syndesizer", "syndump", "xslt_actor"]
 
 
 # Dependencies