Specify environment variables to contract binary (#355)

examples/c_contract/hotpocket_contract.h

@@ -158,6 +158,7 @@ struct hp_config
     struct hp_unl_collection unl;
     char *bin_path;
     char *bin_args;
+    char *environment;
     uint32_t roundtime;
     uint32_t stage_slice;
     char *consensus;
@@ -584,6 +585,7 @@ void hp_free_config(struct hp_config *config)
     __HP_FREE(config->unl.list);
     __HP_FREE(config->bin_path);
     __HP_FREE(config->bin_args);
+    __HP_FREE(config->environment);
     __HP_FREE(config->consensus);
     __HP_FREE(config->npl);
     __HP_FREE(config->appbill.mode);
@@ -737,7 +739,7 @@ int __hp_write_to_patch_file(const int fd, const struct hp_config *config)
 
     // Top-level field values.
 
-    const char *json_string = "    \"bin_path\": \"%s\",\n    \"bin_args\": \"%s\",\n    \"roundtime\": %s,\n    \"stage_slice\": %s,\n"
+    const char *json_string = "    \"bin_path\": \"%s\",\n    \"bin_args\": \"%s\",\n    \"environment\": \"%s\",\n    \"roundtime\": %s,\n    \"stage_slice\": %s,\n"
                               "    \"consensus\": \"%s\",\n    \"npl\": \"%s\",\n    \"max_input_ledger_offset\": %s,\n";
 
     char roundtime_str[16];
@@ -749,11 +751,11 @@ int __hp_write_to_patch_file(const int fd, const struct hp_config *config)
     char max_input_ledger_offset_str[16];
     sprintf(max_input_ledger_offset_str, "%d", config->max_input_ledger_offset);
 
-    const size_t json_string_len = 149 + strlen(config->bin_path) + strlen(config->bin_args) +
+    const size_t json_string_len = 172 + strlen(config->bin_path) + strlen(config->bin_args) + strlen(config->environment) +
                                    strlen(roundtime_str) + strlen(stage_slice_str) +
                                    strlen(config->consensus) + strlen(config->npl) + strlen(max_input_ledger_offset_str);
     char json_buf[json_string_len];
-    sprintf(json_buf, json_string, config->bin_path, config->bin_args, roundtime_str, stage_slice_str, config->consensus, config->npl, max_input_ledger_offset_str);
+    sprintf(json_buf, json_string, config->bin_path, config->bin_args, config->environment, roundtime_str, stage_slice_str, config->consensus, config->npl, max_input_ledger_offset_str);
     iov_vec[2].iov_base = json_buf;
     iov_vec[2].iov_len = json_string_len;
 
@@ -844,6 +846,10 @@ void __hp_populate_patch_from_json_object(struct hp_config *config, const struct
         {
             __HP_ASSIGN_CHAR_PTR(config->bin_args, elem);
         }
+        else if (strcmp(k->string, "environment") == 0)
+        {
+            __HP_ASSIGN_CHAR_PTR(config->environment, elem);
+        }
         else if (strcmp(k->string, "roundtime") == 0)
         {
             const struct json_number_s *value = (struct json_number_s *)elem->value->payload;

src/conf.cpp

@@ -948,6 +948,7 @@ namespace conf
         jdoc.insert_or_assign("unl", unl);
         jdoc.insert_or_assign("bin_path", contract.bin_path);
         jdoc.insert_or_assign("bin_args", contract.bin_args);
+        jdoc.insert_or_assign("environment", contract.environment);
         jdoc.insert_or_assign("roundtime", contract.roundtime.load());
         jdoc.insert_or_assign("stage_slice", contract.stage_slice.load());
         jdoc.insert_or_assign("consensus", contract.is_consensus_public ? PUBLIC : PRIVATE);
@@ -1045,6 +1046,7 @@ namespace conf
 
             contract.bin_path = jdoc["bin_path"].as<std::string>();
             contract.bin_args = jdoc["bin_args"].as<std::string>();
+            contract.environment = jdoc["environment"].as<std::string>();
 
             contract.roundtime = jdoc["roundtime"].as<uint32_t>();
             if (contract.roundtime < 1 || contract.roundtime > MAX_ROUND_TIME)
@@ -1093,6 +1095,11 @@ namespace conf
             return -1;
         }
 
+        contract.runtime_env_args.clear();
+        // Populate runtime environment args.
+        if (!contract.environment.empty())
+            util::split_string(contract.runtime_env_args, contract.environment, " ");
+
         contract.runtime_binexec_args.clear();
         // Populate runtime contract execution args.
         if (!contract.bin_args.empty())

src/conf.hpp

@@ -182,6 +182,7 @@ namespace conf
         std::set<std::string> unl;             // Unique node list (list of binary public keys).
         std::string bin_path;                  // Full path to the contract binary.
         std::string bin_args;                  // CLI arguments to pass to the contract binary.
+        std::string environment;               // Environment variables to be passed into contract.
         std::atomic<uint32_t> roundtime = 0;   // Consensus round time in ms (max: 3,600,000).
         std::atomic<uint32_t> stage_slice = 0; // Percentage slice of round time that stages 0,1,2 get (max: 33).
         bool is_consensus_public = false;      // If true, consensus are broadcasted to non-unl nodes as well.
@@ -192,6 +193,7 @@ namespace conf
 
         // Config element which are initialized in memory (This is not directly loaded from the config file)
         std::vector<std::string> runtime_binexec_args; // Contract binary execution args used during runtime.
+        std::vector<std::string> runtime_env_args;     // Contract environment variables.
     };
 
     struct user_config

src/sc/sc.cpp

@@ -210,6 +210,12 @@ namespace sc
                 execv_args[j] = conf::cfg.contract.runtime_binexec_args[i].data();
             execv_args[len - 1] = NULL;
 
+            len = conf::cfg.contract.runtime_env_args.size() + 1;
+            char *env_args[len];
+            for (int i = 0; i < conf::cfg.contract.runtime_env_args.size(); i++)
+                env_args[i] = conf::cfg.contract.runtime_env_args[i].data();
+            env_args[len - 1] = NULL;
+
             if (chdir(ctx.working_dir.c_str()) == -1)
             {
                 std::cerr << errno << ": Contract process chdir failed." << (ctx.args.readonly ? " (rdonly)" : "") << "\n";
@@ -224,8 +230,8 @@ namespace sc
                 exit(1);
             }
 
-            execv(execv_args[0], execv_args);
-            std::cerr << errno << ": Contract process execv failed." << (ctx.args.readonly ? " (rdonly)" : "") << "\n";
+            execve(execv_args[0], execv_args, env_args);
+            std::cerr << errno << ": Contract process execve failed." << (ctx.args.readonly ? " (rdonly)" : "") << "\n";
             exit(1);
         }
         else

test/local-cluster/cluster-create.sh

@@ -111,6 +111,7 @@ do
                     id: '3c349abe-4d70-4f50-9fa6-018f1f2530ab', \
                     bin_path: '$binary', \
                     bin_args: '$binargs', \
+                    environment: '', \
                     roundtime: $roundtime, \
                     consensus: 'public', \
                     npl: 'public', \