MEDIUM: promex: Update the promex applet to use their own buffers

Thanks to this patch, the promex applet is now using its own buffers.
.rcv_buf and .snd_buf callback functions are now defined to use the default
HTX functions. Parts to receive and send data have also been updated to use
the applet API and to remove any dependencies on the stream-connectors and
the channels.

diff --git a/addons/promex/include/promex/promex.h b/addons/promex/include/promex/promex.h
index 7b838da153fb4b22db5cb7f297a41a2fe8977df1..1570e3d2477e5181a7a07bfa23d78cd862ef84b1 100644 (file)
--- a/addons/promex/include/promex/promex.h
+++ b/addons/promex/include/promex/promex.h
@@ -32,7 +32,7 @@
 
 /* Prometheus exporter flags (ctx->flags) */
 #define PROMEX_FL_METRIC_HDR        0x00000001
-/* unused: 0x00000002 */
+#define PROMEX_FL_BODYLESS_RESP     0x00000002
 /* unused: 0x00000004 */
 /* unused: 0x00000008 */
 /* unused: 0x00000010 */

diff --git a/addons/promex/service-prometheus.c b/addons/promex/service-prometheus.c
index 7c429051dd244c2b0d869f59fac6d92a3c7cc709..42240a9d69d52e7db08ec832c0422b28b5a534d7 100644 (file)
--- a/addons/promex/service-prometheus.c
+++ b/addons/promex/service-prometheus.c
@@ -427,9 +427,8 @@ static int promex_dump_global_metrics(struct appctx *appctx, struct htx *htx)
        static struct ist prefix = IST("haproxy_process_");
        struct promex_ctx *ctx = appctx->svcctx;
        struct field val;
-       struct channel *chn = sc_ic(appctx_sc(appctx));
        struct ist name, desc, out = ist2(trash.area, 0);
-       size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
+       size_t max = htx_get_max_blksz(htx, applet_htx_output_room(appctx));
        int ret = 1;
 
        if (!stats_fill_info(stat_line_info, ST_I_INF_MAX, 0))
@@ -495,7 +494,6 @@ static int promex_dump_global_metrics(struct appctx *appctx, struct htx *htx)
        if (out.len) {
                if (!htx_add_data_atonce(htx, out))
                        return -1; /* Unexpected and unrecoverable error */
-               channel_add_input(chn, out.len);
        }
        return ret;
   full:
@@ -512,9 +510,8 @@ static int promex_dump_front_metrics(struct appctx *appctx, struct htx *htx)
        struct proxy *px = ctx->p[0];
        struct stats_module *mod = ctx->p[1];
        struct field val;
-       struct channel *chn = sc_ic(appctx_sc(appctx));
        struct ist name, desc, out = ist2(trash.area, 0);
-       size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
+       size_t max = htx_get_max_blksz(htx, applet_htx_output_room(appctx));
        struct field *stats = stat_lines[STATS_DOMAIN_PROXY];
        int ret = 1;
        enum promex_front_state state;
@@ -694,7 +691,6 @@ static int promex_dump_front_metrics(struct appctx *appctx, struct htx *htx)
        if (out.len) {
                if (!htx_add_data_atonce(htx, out))
                        return -1; /* Unexpected and unrecoverable error */
-               channel_add_input(chn, out.len);
        }
 
        /* Save pointers (0=current proxy, 1=current stats module) of the current context */
@@ -716,9 +712,8 @@ static int promex_dump_listener_metrics(struct appctx *appctx, struct htx *htx)
        struct listener *li = ctx->p[1];
        struct stats_module *mod = ctx->p[2];
        struct field val;
-       struct channel *chn = sc_ic(appctx_sc(appctx));
        struct ist name, desc, out = ist2(trash.area, 0);
-       size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
+       size_t max = htx_get_max_blksz(htx, applet_htx_output_room(appctx));
        struct field *stats = stat_lines[STATS_DOMAIN_PROXY];
        int ret = 1;
        enum li_status status;
@@ -899,7 +894,6 @@ static int promex_dump_listener_metrics(struct appctx *appctx, struct htx *htx)
        if (out.len) {
                if (!htx_add_data_atonce(htx, out))
                        return -1; /* Unexpected and unrecoverable error */
-               channel_add_input(chn, out.len);
        }
        /* Save pointers (0=current proxy, 1=current listener, 2=current stats module) of the current context */
        ctx->p[0] = px;
@@ -921,9 +915,8 @@ static int promex_dump_back_metrics(struct appctx *appctx, struct htx *htx)
        struct stats_module *mod = ctx->p[1];
        struct server *sv;
        struct field val;
-       struct channel *chn = sc_ic(appctx_sc(appctx));
        struct ist name, desc, out = ist2(trash.area, 0);
-       size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
+       size_t max = htx_get_max_blksz(htx, applet_htx_output_room(appctx));
        struct field *stats = stat_lines[STATS_DOMAIN_PROXY];
        int ret = 1;
        double secs;
@@ -1185,7 +1178,6 @@ static int promex_dump_back_metrics(struct appctx *appctx, struct htx *htx)
        if (out.len) {
                if (!htx_add_data_atonce(htx, out))
                        return -1; /* Unexpected and unrecoverable error */
-               channel_add_input(chn, out.len);
        }
        /* Save pointers (0=current proxy, 1=current stats module) of the current context */
        ctx->p[0] = px;
@@ -1206,9 +1198,8 @@ static int promex_dump_srv_metrics(struct appctx *appctx, struct htx *htx)
        struct server *sv = ctx->p[1];
        struct stats_module *mod = ctx->p[2];
        struct field val;
-       struct channel *chn = sc_ic(appctx_sc(appctx));
        struct ist name, desc, out = ist2(trash.area, 0);
-       size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
+       size_t max = htx_get_max_blksz(htx, applet_htx_output_room(appctx));
        struct field *stats = stat_lines[STATS_DOMAIN_PROXY];
        int ret = 1;
        double secs;
@@ -1507,7 +1498,6 @@ static int promex_dump_srv_metrics(struct appctx *appctx, struct htx *htx)
        if (out.len) {
                if (!htx_add_data_atonce(htx, out))
                        return -1; /* Unexpected and unrecoverable error */
-               channel_add_input(chn, out.len);
        }
 
        /* Decrement server refcount if it was saved through ctx.p[1]. */
@@ -1603,9 +1593,8 @@ static int promex_dump_ref_modules_metrics(struct appctx *appctx, struct htx *ht
 {
        struct promex_ctx *ctx = appctx->svcctx;
        struct promex_module_ref *ref = ctx->p[0];
-       struct channel *chn = sc_ic(appctx_sc(appctx));
        struct ist out = ist2(trash.area, 0);
-       size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
+       size_t max = htx_get_max_blksz(htx, applet_htx_output_room(appctx));
        int ret = 1;
 
        if (!ref) {
@@ -1629,7 +1618,6 @@ static int promex_dump_ref_modules_metrics(struct appctx *appctx, struct htx *ht
        if (out.len) {
                if (!htx_add_data_atonce(htx, out))
                        return -1; /* Unexpected and unrecoverable error */
-               channel_add_input(chn, out.len);
        }
        ctx->p[0] = ref;
        return ret;
@@ -1644,9 +1632,8 @@ static int promex_dump_all_modules_metrics(struct appctx *appctx, struct htx *ht
 {
        struct promex_ctx *ctx = appctx->svcctx;
        struct promex_module *mod = ctx->p[0];
-       struct channel *chn = sc_ic(appctx_sc(appctx));
        struct ist out = ist2(trash.area, 0);
-       size_t max = htx_get_max_blksz(htx, channel_htx_recv_max(chn, htx));
+       size_t max = htx_get_max_blksz(htx, applet_htx_output_room(appctx));
        int ret = 1;
 
        if (!mod) {
@@ -1670,7 +1657,6 @@ static int promex_dump_all_modules_metrics(struct appctx *appctx, struct htx *ht
        if (out.len) {
                if (!htx_add_data_atonce(htx, out))
                        return -1; /* Unexpected and unrecoverable error */
-               channel_add_input(chn, out.len);
        }
        ctx->p[0] = mod;
        return ret;
@@ -1685,7 +1671,7 @@ static int promex_dump_all_modules_metrics(struct appctx *appctx, struct htx *ht
  * Uses <appctx.ctx.stats.px> as a pointer to the current proxy and <sv>/<li>
  * as pointers to the current server/listener respectively.
  */
-static int promex_dump_metrics(struct appctx *appctx, struct stconn *sc, struct htx *htx)
+static int promex_dump_metrics(struct appctx *appctx, struct htx *htx)
 {
        struct promex_ctx *ctx = appctx->svcctx;
        int ret;
@@ -1809,7 +1795,7 @@ static int promex_dump_metrics(struct appctx *appctx, struct stconn *sc, struct
        return 1;
 
   full:
-       sc_need_room(sc, channel_htx_recv_max(sc_ic(appctx_sc(appctx)), htx) + 1);
+       applet_have_more_data(appctx);
        return 0;
   error:
        /* unrecoverable error */
@@ -1822,12 +1808,11 @@ static int promex_dump_metrics(struct appctx *appctx, struct stconn *sc, struct
 
 /* Parse the query string of request URI to filter the metrics. It returns 1 on
  * success and -1 on error. */
-static int promex_parse_uri(struct appctx *appctx, struct stconn *sc)
+static int promex_parse_uri(struct appctx *appctx)
 {
        struct promex_ctx *ctx = appctx->svcctx;
-       struct channel *req = sc_oc(sc);
-       struct channel *res = sc_ic(sc);
-       struct htx *req_htx, *res_htx;
+       struct buffer *outbuf;
+       struct htx *req_htx;
        struct htx_sl *sl;
        char *p, *key, *value;
        const char *end;
@@ -1837,10 +1822,13 @@ static int promex_parse_uri(struct appctx *appctx, struct stconn *sc)
        int len;
 
        /* Get the query-string */
-       req_htx = htxbuf(&req->buf);
+       req_htx = htxbuf(DISGUISE(applet_get_inbuf(appctx)));
        sl = http_get_stline(req_htx);
        if (!sl)
-               goto error;
+               goto bad_req_error;
+       if (sl->info.req.meth == HTTP_METH_HEAD)
+               ctx->flags |= PROMEX_FL_BODYLESS_RESP;
+
        p = http_find_param_list(HTX_SL_REQ_UPTR(sl), HTX_SL_REQ_ULEN(sl), '?');
        if (!p)
                goto end;
@@ -1873,27 +1861,27 @@ static int promex_parse_uri(struct appctx *appctx, struct stconn *sc)
                        *p = 0;
                len = url_decode(key, 1);
                if (len == -1)
-                       goto error;
+                       goto bad_req_error;
 
                /* decode value */
                if (value) {
                        while (p < end && *p != '=' && *p != '&' && *p != '#')
                                ++p;
                        if (*p == '=')
-                               goto error;
+                               goto bad_req_error;
                        if (*p == '&')
                                *(p++) = 0;
                        else if (*p == '#')
                                *p = 0;
                        len = url_decode(value, 1);
                        if (len == -1)
-                               goto error;
+                               goto bad_req_error;
                }
 
                if (strcmp(key, "scope") == 0) {
                        default_scopes = 0; /* at least a scope defined, unset default scopes */
                        if (!value)
-                               goto error;
+                               goto bad_req_error;
                        else if (*value == 0)
                                ctx->flags &= ~PROMEX_FL_SCOPE_ALL;
                        else if (*value == '*' && *(value+1) == 0)
@@ -1924,14 +1912,14 @@ static int promex_parse_uri(struct appctx *appctx, struct stconn *sc)
                                        }
                                }
                                if (!(ctx->flags & PROMEX_FL_SCOPE_MODULE))
-                                       goto error;
+                                       goto bad_req_error;
                        }
                }
                else if (strcmp(key, "metrics") == 0) {
                        struct ist args;
 
                        if (!value)
-                               goto error;
+                               goto bad_req_error;
 
                        for (args = ist(value); istlen(args); args = istadv(istfind(args, ','), 1)) {
                                struct eb32_node *node;
@@ -1982,30 +1970,28 @@ static int promex_parse_uri(struct appctx *appctx, struct stconn *sc)
        ctx->flags |= (default_scopes | default_metrics_filter);
        return 1;
 
-  error:
+  bad_req_error:
        err = &http_err_chunks[HTTP_ERR_400];
-       channel_erase(res);
-       res->buf.data = b_data(err);
-       memcpy(res->buf.area, b_head(err), b_data(err));
-       res_htx = htx_from_buf(&res->buf);
-       channel_add_input(res, res_htx->data);
-       return -1;
+       goto error;
 
   internal_error:
-       err = &http_err_chunks[HTTP_ERR_400];
-       channel_erase(res);
-       res->buf.data = b_data(err);
-       memcpy(res->buf.area, b_head(err), b_data(err));
-       res_htx = htx_from_buf(&res->buf);
-       channel_add_input(res, res_htx->data);
+       err = &http_err_chunks[HTTP_ERR_500];
+       goto error;
+
+  error:
+       outbuf = DISGUISE(applet_get_outbuf(appctx));
+       b_reset(outbuf);
+       outbuf->data = b_data(err);
+       memcpy(outbuf->area, b_head(err), b_data(err));
+       applet_set_eoi(appctx);
+       applet_set_eos(appctx);
        return -1;
 }
 
 /* Send HTTP headers of the response. It returns 1 on success and 0 if <htx> is
  * full. */
-static int promex_send_headers(struct appctx *appctx, struct stconn *sc, struct htx *htx)
+static int promex_send_headers(struct appctx *appctx, struct htx *htx)
 {
-       struct channel *chn = sc_ic(sc);
        struct htx_sl *sl;
        unsigned int flags;
 
@@ -2020,11 +2006,10 @@ static int promex_send_headers(struct appctx *appctx, struct stconn *sc, struct
            !htx_add_endof(htx, HTX_BLK_EOH))
                goto full;
 
-       channel_add_input(chn, htx->data);
        return 1;
   full:
        htx_reset(htx);
-       sc_need_room(sc, 0);
+       applet_have_more_data(appctx);
        return 0;
 }
 
@@ -2078,52 +2063,51 @@ static void promex_appctx_release(struct appctx *appctx)
 /* The main I/O handler for the promex applet. */
 static void promex_appctx_handle_io(struct appctx *appctx)
 {
-       struct stconn *sc = appctx_sc(appctx);
-       struct stream *s = __sc_strm(sc);
-       struct channel *req = sc_oc(sc);
-       struct channel *res = sc_ic(sc);
-       struct htx *req_htx, *res_htx;
+       struct promex_ctx *ctx = appctx->svcctx;
+       struct buffer *outbuf;
+       struct htx *res_htx;
        int ret;
 
-       res_htx = htx_from_buf(&res->buf);
-
-       if (unlikely(se_fl_test(appctx->sedesc, (SE_FL_EOS|SE_FL_ERROR|SE_FL_SHR|SE_FL_SHW))))
+       if (unlikely(applet_fl_test(appctx, APPCTX_FL_EOS|APPCTX_FL_ERROR)))
                goto out;
 
        /* Check if the input buffer is available. */
-       if (!b_size(&res->buf)) {
-               sc_need_room(sc, 0);
+       outbuf = applet_get_outbuf(appctx);
+       if (outbuf == NULL) {
+               applet_have_more_data(appctx);
                goto out;
        }
+       res_htx = htx_from_buf(outbuf);
 
        switch (appctx->st0) {
                case PROMEX_ST_INIT:
-                       if (!co_data(req)) {
+                       if (!applet_get_inbuf(appctx) || !applet_htx_input_data(appctx)) {
                                applet_need_more_data(appctx);
-                               goto out;
+                               break;
                        }
-                       ret = promex_parse_uri(appctx, sc);
+
+                       ret = promex_parse_uri(appctx);
                        if (ret <= 0) {
                                if (ret == -1)
-                                       goto error;
-                               goto out;
+                                       applet_set_error(appctx);
+                               break;
                        }
                        appctx->st0 = PROMEX_ST_HEAD;
                        appctx->st1 = PROMEX_DUMPER_INIT;
                        __fallthrough;
 
                case PROMEX_ST_HEAD:
-                       if (!promex_send_headers(appctx, sc, res_htx))
-                               goto out;
-                       appctx->st0 = ((s->txn->meth == HTTP_METH_HEAD) ? PROMEX_ST_DONE : PROMEX_ST_DUMP);
+                       if (!promex_send_headers(appctx, res_htx))
+                               break;
+                       appctx->st0 = ((ctx->flags & PROMEX_FL_BODYLESS_RESP) ? PROMEX_ST_DONE : PROMEX_ST_DUMP);
                        __fallthrough;
 
                case PROMEX_ST_DUMP:
-                       ret = promex_dump_metrics(appctx, sc, res_htx);
+                       ret = promex_dump_metrics(appctx, res_htx);
                        if (ret <= 0) {
                                if (ret == -1)
-                                       goto error;
-                               goto out;
+                                       applet_set_error(appctx);
+                               break;
                        }
                        appctx->st0 = PROMEX_ST_DONE;
                        __fallthrough;
@@ -2137,33 +2121,25 @@ static void promex_appctx_handle_io(struct appctx *appctx)
                         */
                        if (htx_is_empty(res_htx)) {
                                if (!htx_add_endof(res_htx, HTX_BLK_EOT)) {
-                                       sc_need_room(sc, sizeof(struct htx_blk) + 1);
-                                       goto out;
+                                       applet_have_more_data(appctx);
+                                       break;
                                }
-                               channel_add_input(res, 1);
                        }
                        res_htx->flags |= HTX_FL_EOM;
-                       se_fl_set(appctx->sedesc, SE_FL_EOI);
+                       applet_set_eoi(appctx);
                        appctx->st0 = PROMEX_ST_END;
                        __fallthrough;
 
                case PROMEX_ST_END:
-                       se_fl_set(appctx->sedesc, SE_FL_EOS);
+                       applet_set_eos(appctx);
        }
 
-  out:
-       htx_to_buf(res_htx, &res->buf);
+       htx_to_buf(res_htx, outbuf);
 
+  out:
        /* eat the whole request */
-       if (co_data(req)) {
-               req_htx = htx_from_buf(&req->buf);
-               co_htx_skip(req, req_htx, co_data(req));
-       }
+       applet_reset_input(appctx);
        return;
-
-  error:
-       se_fl_set(appctx->sedesc, SE_FL_ERROR);
-       goto out;
 }
 
 struct applet promex_applet = {
@@ -2172,6 +2148,8 @@ struct applet promex_applet = {
        .init = promex_appctx_init,
        .release = promex_appctx_release,
        .fct = promex_appctx_handle_io,
+       .rcv_buf = appctx_htx_rcv_buf,
+       .snd_buf = appctx_htx_snd_buf,
 };
 
 static enum act_parse_ret service_parse_prometheus_exporter(const char **args, int *cur_arg, struct proxy *px,