MINOR: httpclient/cli: implement a simple client over the CLI

This commit implements an HTTP Client over the CLI, this was made as
working example for the HTTP Client API.

It usable over the CLI by specifying a method and an URL:

    echo "httpclient GET http://127.0.0.1:8000/demo.file" | socat /tmp/haproxy.sock -

Only IP addresses are accessibles since the API does not allow to
resolve addresses yet.

diff --git a/src/http_client.c b/src/http_client.c
index 9f148b48148c9a4694427518ba33af03f9ea410f..ea978604932ef471bf89408c027c69f26f364ff9 100644 (file)
--- a/src/http_client.c
+++ b/src/http_client.c
@@ -40,6 +40,202 @@ static struct server *httpclient_srv_ssl;
 
 static struct applet httpclient_applet;
 
+/* --- This part of the file implement an HTTP client over the CLI ---
+ * The functions will be  starting by "hc_cli" for "httpclient cli"
+ */
+
+static struct http_hdr default_httpclient_hdrs[2] = {
+               { .n = IST("User-Agent"), .v = IST("HAProxy HTTP client") },
+               { .n = IST_NULL, .v = IST_NULL },
+};
+
+
+/* What kind of data we need to read */
+#define HC_CLI_F_RES_STLINE     0x01
+#define HC_CLI_F_RES_HDR        0x02
+#define        HC_CLI_F_RES_BODY       0x04
+#define HC_CLI_F_RES_END        0x08
+
+
+/* These are the callback used by the HTTP Client when it needs to notify new
+ * data, we only sets a flag in the IO handler  */
+
+void hc_cli_res_stline_cb(struct httpclient *hc)
+{
+       struct appctx *appctx = hc->caller;
+
+       appctx->ctx.cli.i0 |= HC_CLI_F_RES_STLINE;
+       if (appctx)
+               appctx_wakeup(appctx);
+}
+
+void hc_cli_res_headers_cb(struct httpclient *hc)
+{
+       struct appctx *appctx = hc->caller;
+
+       appctx->ctx.cli.i0 |= HC_CLI_F_RES_HDR;
+       if (appctx)
+               appctx_wakeup(appctx);
+}
+
+void hc_cli_res_body_cb(struct httpclient *hc)
+{
+       struct appctx *appctx = hc->caller;
+
+       appctx->ctx.cli.i0 |= HC_CLI_F_RES_BODY;
+       if (appctx)
+               appctx_wakeup(appctx);
+}
+
+void hc_cli_res_end_cb(struct httpclient *hc)
+{
+       struct appctx *appctx = hc->caller;
+
+       appctx->ctx.cli.i0 |= HC_CLI_F_RES_END;
+       if (appctx)
+               appctx_wakeup(appctx);
+}
+
+/*
+ * Parse an httpclient keyword on the cli:
+ * httpclient <ID> <method> <URI>
+ */
+static int hc_cli_parse(char **args, char *payload, struct appctx *appctx, void *private)
+{
+       struct httpclient *hc;
+       char *err = NULL;
+       enum http_meth_t meth;
+       char *meth_str;
+       struct ist uri;
+
+       if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
+               return 1;
+
+       if (!*args[1] || !*args[2]) {
+               memprintf(&err, ": not enough parameters");
+               goto err;
+       }
+
+       meth_str = args[1];
+       uri = ist(args[2]);
+
+       meth = find_http_meth(meth_str, strlen(meth_str));
+
+       hc = httpclient_new(appctx, meth, uri);
+       if (!hc) {
+               goto err;
+       }
+
+       /* update the httpclient callbacks */
+       hc->ops.res_stline = hc_cli_res_stline_cb;
+       hc->ops.res_headers = hc_cli_res_headers_cb;
+       hc->ops.res_payload = hc_cli_res_body_cb;
+       hc->ops.res_end = hc_cli_res_end_cb;
+
+       appctx->ctx.cli.p0 = hc; /* store the httpclient ptr in the applet */
+       appctx->ctx.cli.i0 = 0;
+
+       if (httpclient_req_gen(hc, hc->req.url, hc->req.meth, default_httpclient_hdrs) != ERR_NONE)
+               goto err;
+
+
+       if (!httpclient_start(hc))
+               goto err;
+
+       return 0;
+
+err:
+       memprintf(&err, "Can't start the HTTP client%s.\n", err ? err : "");
+       return cli_err(appctx, err);
+}
+
+/* This function dumps the content of the httpclient receive buffer
+ * on the CLI output
+ *
+ * Return 1 when the processing is finished
+ * return 0 if it needs to be called again
+ */
+static int hc_cli_io_handler(struct appctx *appctx)
+{
+       struct stream_interface *si = appctx->owner;
+       struct buffer *trash = alloc_trash_chunk();
+       struct httpclient *hc = appctx->ctx.cli.p0;
+       struct http_hdr *hdrs, *hdr;
+
+       if (!trash)
+               goto out;
+       if (appctx->ctx.cli.i0 & HC_CLI_F_RES_STLINE) {
+               chunk_appendf(trash, "%s %d %s\n",ist0(hc->res.vsn), hc->res.status, ist0(hc->res.reason));
+               if (ci_putchk(si_ic(si), trash) == -1)
+                       si_rx_room_blk(si);
+               appctx->ctx.cli.i0 &= ~HC_CLI_F_RES_STLINE;
+               goto out;
+       }
+
+       if (appctx->ctx.cli.i0 & HC_CLI_F_RES_HDR) {
+               hdrs = hc->res.hdrs;
+               for (hdr = hdrs; isttest(hdr->v); hdr++) {
+                       if (!h1_format_htx_hdr(hdr->n, hdr->v, trash))
+                               goto out;
+               }
+               if (!chunk_memcat(trash, "\r\n", 2))
+                       goto out;
+               if (ci_putchk(si_ic(si), trash) == -1)
+                       si_rx_room_blk(si);
+               appctx->ctx.cli.i0 &= ~HC_CLI_F_RES_HDR;
+               goto out;
+       }
+
+       if (appctx->ctx.cli.i0 & HC_CLI_F_RES_BODY) {
+               int ret;
+
+               ret = httpclient_res_xfer(hc, &si_ic(si)->buf);
+               channel_add_input(si_ic(si), ret); /* forward what we put in the buffer channel */
+
+               if (!b_data(&hc->res.buf)) {/* remove the flag if the buffer was emptied */
+                       appctx->ctx.cli.i0 &= ~HC_CLI_F_RES_BODY;
+               }
+               goto out;
+       }
+
+       /* we must close only if F_END is the last flag */
+       if (appctx->ctx.cli.i0 ==  HC_CLI_F_RES_END) {
+               si_shutw(si);
+               si_shutr(si);
+               appctx->ctx.cli.i0 &= ~HC_CLI_F_RES_END;
+               goto out;
+       }
+
+out:
+       /* we didn't clear every flags, we should come back to finish things */
+       if (appctx->ctx.cli.i0)
+               si_rx_room_blk(si);
+
+       free_trash_chunk(trash);
+       return 0;
+}
+
+static void hc_cli_release(struct appctx *appctx)
+{
+       struct httpclient *hc = appctx->ctx.cli.p0;
+
+       /* Everything possible was printed on the CLI, we can destroy the client */
+       httpclient_destroy(hc);
+
+       return;
+}
+
+/* register cli keywords */
+static struct cli_kw_list cli_kws = {{ },{
+       { { "httpclient", NULL }, "httpclient <method> <URI>   : launch an HTTP request", hc_cli_parse, hc_cli_io_handler, hc_cli_release},
+       { { NULL }, NULL, NULL, NULL }
+}};
+
+INITCALL1(STG_REGISTER, cli_register_kw, &cli_kws);
+
+
+/* --- This part of the file implements the actual HTTP client API --- */
+
 /*
  * Generate a simple request and fill the httpclient request buffer with it.
  * The request contains a request line generated from the absolute <url> and