From 8dc3c7b7693569ac83857e6fe5cdd9b09ebda7bd Mon Sep 17 00:00:00 2001
From: Andreas Baumann <mail@andreasbaumann.cc>
Date: Fri, 10 Apr 2015 07:31:21 +0200
Subject: supporting variables in worker command now

---
 examples/build_gold_image/biruda.conf |  4 --
 src/worker.c                          | 95 +++++++++++++++++++++++++++++++++--
 2 files changed, 92 insertions(+), 7 deletions(-)

diff --git a/examples/build_gold_image/biruda.conf b/examples/build_gold_image/biruda.conf
index 4b68f1a..ae21ef8 100644
--- a/examples/build_gold_image/biruda.conf
+++ b/examples/build_gold_image/biruda.conf
@@ -24,8 +24,6 @@ worker example_build_gold
 	execution = direct
 
 	command = "/bin/sh ./build_centos6.sh ${ARCH}"
-#	command = "/bin/sh ./build_centos6.sh x86_64"
-#	command = "/bin/sh ./build_centos6.sh i686"
 }
 
 worker example_run
@@ -37,8 +35,6 @@ worker example_run
 	execution = direct
 
 	command = "/bin/chroot rhel6-${ARCH} /bin/bash -c '/bin/cat /etc/redhat-release'"
-#	command = "/bin/chroot rhel6-x64 /bin/bash -c '/bin/cat /etc/redhat-release'"
-#	command = "/bin/chroot rhel6-i686 /bin/bash -c '/bin/cat /etc/redhat-release'"
 }
 
 webserver
diff --git a/src/worker.c b/src/worker.c
index 287371a..7807697 100644
--- a/src/worker.c
+++ b/src/worker.c
@@ -18,6 +18,8 @@
 
 #include "json-c/json.h"
 
+#include "system.h"
+
 const char *worker_exection_mode_str( worker_execution_mode_t mode )
 {
 	switch( mode ) {
@@ -255,18 +257,103 @@ static gboolean watch_output( GIOChannel *channel, GIOCondition condition, gpoin
 	return TRUE;
 }
 
+static char *expand_system_variables( const char *s )
+{
+	char *r = (char *)malloc( strlen( s ) * 2 );
+	char *d = r;
+	bool var_begin = false;
+	bool in_var = false;
+	const char *var = NULL;
+	const char *p = s;
+	
+	while( *p != '\0' && d - r < strlen( s ) * 2 - 1 ) {
+		switch( *p ) {
+			case '$':
+				var_begin = true;
+				break;
+			
+			case '{':
+				if( var_begin ) {
+					in_var = true;
+					var = p + 1;
+				} else {
+					fprintf( stderr, "ERROR: Unexpected '{' at position %d in '%s'\n", p-s, s );
+					free( r );
+					return NULL;
+				}
+				break;
+			
+			case '}':
+				if( var_begin ) {
+					fprintf( stderr, "ERROR: Empty variable declaration '${}' at position %d in '%s'\n", p-s, s );
+					free( r );
+					return NULL;
+				}
+				in_var = false;
+				var_begin = false;
+				if( strncmp( var, "ARCH", 4 ) == 0 ) {
+					char machine_arch[100];
+					system_arch( machine_arch, sizeof( machine_arch ) );
+					strncpy( d, machine_arch, strlen( machine_arch ) );
+					d += strlen( machine_arch );
+				} else if( strncmp( var, "OS", 2 ) == 0 ) {
+					char os_name[100];
+					system_os( os_name, sizeof( os_name ) );
+					strncpy( d, os_name, strlen( os_name ) );
+					d += strlen( os_name );
+				} else if( strncmp( var, "HOST", 4 ) == 0 ) {
+					char hostname[100];
+					gethostname( hostname, sizeof( hostname ) );
+					strncpy( d, hostname, strlen( hostname ) );
+					d += strlen( hostname );
+				} else if( strncmp( var, "CPUS", 4 ) == 0 ) {
+					unsigned int nofCpus = system_available_cpus( );
+					char buf[10];
+					snprintf( buf, sizeof( buf ), "%d", nofCpus );
+					strncpy( d, buf, strlen( buf ) );
+					d += strlen( buf );
+				} else {
+					fprintf( stderr, "ERROR: Unknown variable '${%*s}' at position %d in '%s'\n", p-var, var, p-s, s );
+					free( r );
+					return NULL;
+				}
+				break;
+			
+			default:
+				if( in_var ) {
+					var_begin = false;
+				} else {
+					*d = *p;
+					d++;
+				}					
+		}
+		p++;
+	}
+	*d = '\0';
+	
+	return r;
+}
+
 static void *worker_func( void *thread_data )
 {
 	direct_glib_execution_worker_data_t *wed = (direct_glib_execution_worker_data_t *)thread_data;
 	worker_t *worker = wed->worker;
+	
+	char *command = expand_system_variables( worker->command );
+	if( command == NULL ) {
+		fprintf( stderr, "ERROR: Failed to substitute variables in command of worker '%s', '%s'\n",
+			worker->name, command );
+		return NULL;
+	}
 
 	gchar **args;
 	gint nof_args;
 	GError *error = NULL;
-	if( !g_shell_parse_argv( worker->command, &nof_args, &args, &error ) ) {
+	if( !g_shell_parse_argv( command, &nof_args, &args, &error ) ) {
 		fprintf( stderr, "ERROR: Failed to parse command of worker '%s', '%s': %s\n",
-			worker->name, worker->command, error->message );
+			worker->name, command, error->message );
 		g_strfreev( args );
+		free( command );
 		return NULL;
 	}
 		
@@ -283,11 +370,12 @@ static void *worker_func( void *thread_data )
 	if( !ret ) {
 		fprintf( stderr, "ERROR: Starting worker failed: %s\n", error->message );
 		g_strfreev( args );
+		free( command );
 		return NULL;
 	}
 
 	printf( "Worker child with PID " PRIgid " created: %s.\n",
-		wed->pid, worker->command );
+		wed->pid, command );
 
 	char *msg = create_worker_created_answer( worker->name, wed->pid );
 	worker_send_message( worker, msg );	
@@ -327,6 +415,7 @@ static void *worker_func( void *thread_data )
 	worker->execution_data = NULL;
 
 	g_strfreev( args );
+	free( command );
 	
 	return NULL;
 }
-- 
cgit v1.2.3-54-g00ecf