[Tarantool-patches] [PATCH 1/2] core: add setting error injections via env

[Artem Starshov via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Sometimes, it's useful to set error injections via environment
variables and this commit adds this opportunity.

e.g: `ERRINJ_WAL_WRITE=true tarantool` will be launched with
ERRINJ_WAL_WRITE setted to true.

Errinjs with bool parameters can should be set as "true", "TRUE",
"false" or "FALSE".

Errinjs with int or double parameters should be whole valid ("123s" is invalid).
e.g. for int or double: "123", "-1", "2.34", "+2.34".
---
@ChangeLog: Fixed -e option, when tarantool always entered interactive mode when
stdin is a tty. Now, `tarantool -e 'print"Hello"'` doesn't enter interactive mode
as it was before.

 src/lib/core/errinj.c | 26 ++++++++++++++++++++++++++
 src/lib/core/errinj.h |  5 +++++
 src/main.cc           |  1 +
 3 files changed, 32 insertions(+)

diff --git a/src/lib/core/errinj.c b/src/lib/core/errinj.c
index d3aa0ca4f..576811073 100644
--- a/src/lib/core/errinj.c
+++ b/src/lib/core/errinj.c
@@ -66,3 +66,29 @@ int errinj_foreach(errinj_cb cb, void *cb_ctx) {
 	}
 	return 0;
 }
+
+void errinj_scan_env() {
+    for (enum errinj_id i = 0 ; i < errinj_id_MAX ; i++) {
+        struct errinj *inj = &errinjs[i];
+        const char *env_value = getenv(inj->name);
+        if (!env_value || *env_value == '\0')
+            continue;
+
+        if (inj->type == ERRINJ_INT) {
+            char *end;
+            int64_t int_value = strtoll(env_value, &end, 10);
+            if (*end == '\0')
+                inj->iparam = int_value;
+        } else if (inj->type == ERRINJ_BOOL) {
+            if (strcmp(env_value, "false") == 0 || strcmp(env_value, "FALSE"))
+                inj->bparam = false;
+            else if (strcmp(env_value, "true") == 0 || strcmp(env_value, "TRUE"))
+                inj->bparam = true;
+        } else if (inj->type == ERRINJ_DOUBLE) {
+            char *end;
+            double double_value = strtod(env_value, &end);
+            if (*end == '\0')
+                inj->dparam = double_value;
+        }
+    }
+}
diff --git a/src/lib/core/errinj.h b/src/lib/core/errinj.h
index 814c57c2e..dc0657614 100644
--- a/src/lib/core/errinj.h
+++ b/src/lib/core/errinj.h
@@ -168,6 +168,11 @@ typedef int (*errinj_cb)(struct errinj *e, void *cb_ctx);
 int
 errinj_foreach(errinj_cb cb, void *cb_ctx);
 
+/**
+ * Set injections by scanning ERRINJ_$(NAME) in environment variables
+ */
+void errinj_scan_env();
+
 #ifdef NDEBUG
 #  define ERROR_INJECT(ID, CODE)
 #  define ERROR_INJECT_WHILE(ID, CODE)
diff --git a/src/main.cc b/src/main.cc
index 2fce81bb3..2d85c0b24 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -710,6 +710,7 @@ main(int argc, char **argv)
 	memtx_tx_manager_init();
 	crypto_init();
 	systemd_init();
+	errinj_scan_env();
 	tarantool_lua_init(tarantool_bin, main_argc, main_argv);
 
 	start_time = ev_monotonic_time();
-- 
2.28.0