Nettoyage, noms plus coherents, TODO, ...

test~coding~readingCppPrograms.fr/docker-compile-and-run.cpp

@@ -11,14 +11,17 @@ using namespace std;
 
 /**
  * TODO:
+ * - [X] make this into a program rather than a shell script for a minimum of safety
  * - [ ] set tight resources limits
- * - [ ] make this into a program rather than a shell script for a minimum of safety
+ * - [ ] check proper handling of all potential errors
+ * - [ ] make this into a plain C program to not add a dependency on C++
  **/
 
 string compile_and_run = "compile-and-run.sh";
 //string bin_dir = "/home/wims/public_html/bin/";
 string bin_dir = "";
 string docker = "/usr/bin/docker";
+bool verbose = false;
 
 void usage () {
     cerr << "docker-compile-and-run [program.cpp]" << endl;
@@ -28,20 +31,13 @@ void usage () {
     cerr << "The exit status is that of the compiler." << endl;
 }
 
-int system(string command) {
-    // cerr << "Running " << command << endl;
-    std::system(command.c_str());
-}
-
-void report(string comment, string cmd, vector<string> args) {
-    cerr << comment;
-    cerr << cmd;
-    for (auto arg: args)
-        cerr << " " << arg;
-    cerr << endl;
-}
-
-int cpp_exec(string cmd, const vector<string> args) {
+int my_exec(string cmd, const vector<string> args) {
+    if (verbose) {
+        cerr << "exec: " << cmd;
+        for (auto arg: args)
+            cerr << " " << arg;
+        cerr << endl;
+    }
     vector<const char*> argv;
     argv.push_back(cmd.c_str());
     for ( auto &s: args )
@@ -51,9 +47,7 @@ int cpp_exec(string cmd, const vector<string> args) {
     return execv(cmd.c_str(), (char * const*)argv.data());
 }
 
-int exec(string cmd, const vector<string> args, const string in, const string out, const string err) {
-    report("exec: ", cmd, args);
-
+int my_system(string cmd, const vector<string> args, const string in, const string out, const string err) {
     // Taken from man waitpid
     int status;
     pid_t w;
@@ -73,7 +67,7 @@ int exec(string cmd, const vector<string> args, const string in, const string ou
             dup2(fileno(f), STDOUT_FILENO);
             fclose(f);
         }
-        cpp_exec(cmd, args);
+        my_exec(cmd, args);
         perror("exec");
         exit(EXIT_FAILURE);
     }
@@ -85,13 +79,11 @@ int exec(string cmd, const vector<string> args, const string in, const string ou
     return EXIT_SUCCESS;
 }
 
-int exec(string cmd, const vector<string> args) {
-    return exec(cmd, args, "", "", "");
+int my_system(string cmd, const vector<string> args) {
+    return my_system(cmd, args, "", "", "");
 }
 
-std::string pexec(const string cmd, vector<string> args) {
-    report("pexec: ", cmd, args);
-
+std::string my_popen(const string cmd, vector<string> args) {
     int pipefd[2];
     pid_t cpid;
 
@@ -109,7 +101,7 @@ std::string pexec(const string cmd, vector<string> args) {
     if (cpid == 0) {    /* Child writes to pipe */
         close(pipefd[0]);          /* Close unused read end */
         dup2(pipefd[1], STDOUT_FILENO);
-        cpp_exec(cmd, args);
+        my_exec(cmd, args);
         perror("exec");
         exit(EXIT_FAILURE);
     }
@@ -131,7 +123,7 @@ string docker_run(string container, string cmd, vector<string> args) {
     vector<string> docker_args = {"run", "-d", container, cmd};
     for (auto arg: args)
         docker_args.push_back(arg);
-    string ID = pexec(docker, docker_args);
+    string ID = my_popen(docker, docker_args);
     // see http://stackoverflow.com/questions/216823/whats-the-best-way-to-trim-stdstring
     ID.erase(ID.find_last_not_of(" \n\r\t")+1);
     return ID;
@@ -141,26 +133,24 @@ void docker_exec(string docker_id, vector<string> args) {
     vector<string> docker_args = {"exec", "-i", docker_id};
     for (auto arg: args)
         docker_args.push_back(arg);
-    exec(docker, docker_args);
+    my_system(docker, docker_args);
 }
 
 void docker_cp(string docker_id, string source, string target) {
     // See http://stackoverflow.com/questions/22907231/copying-files-from-host-to-docker-container
     // TODO: replace with 'docker cp' of docker 1.8 when possible
-    exec(docker,
-         {"exec", "-i", docker_id, "/bin/bash",  "-c", "cat > "+target,},
-         source, "", "");
+    my_system(docker,
+              {"exec", "-i", docker_id, "/bin/bash",  "-c", "cat > "+target,},
+              source, "", "");
 }
 
 void docker_rm(string docker_id) {
-    exec(docker, {"rm", "-f", docker_id}, "", "/dev/null", "");
+    my_system(docker, {"rm", "-f", docker_id}, "", "/dev/null", "");
 }
 
 int main(int argc, char **argv) {
-    //cout << pexec("/usr/bin/id", {}) << "|" << endl;
-
+    //cout << my_popen("/usr/bin/id", {}) << "|" << endl;
     //printf("egid: %d\n", getegid());
-
     //exec("/usr/bin/id", {});
     //system("/usr/bin/id");
 
@@ -172,12 +162,12 @@ int main(int argc, char **argv) {
     string program=argv[1];
 
     string docker_id = docker_run("crosbymichael/build-essential", "sleep", {"1000"});
-    cout << "docker_id: " << docker_id << endl;
+    if (verbose)
+        cerr << "docker_id: " << docker_id << endl;
     docker_cp(docker_id, bin_dir+compile_and_run, compile_and_run);
     docker_cp(docker_id, program, program);
     docker_exec(docker_id, { "chmod", "700", compile_and_run });
     docker_exec(docker_id, { "./"+compile_and_run, program});
     docker_rm(docker_id);
-    cout.flush();
     return 0;
 }