python: integrate David Strauss' python-systemd package

Makefile.am

@@ -3408,6 +3408,37 @@ EXTRA_DIST += \
 
 # ------------------------------------------------------------------------------
 
+if HAVE_PYTHON_DEVEL
+
+pkgpyexec_LTLIBRARIES = \
+	_journal.la
+
+_journal_la_SOURCES = \
+	src/python-systemd/_journal.c
+
+_journal_la_CFLAGS = \
+	$(AM_CFLAGS) \
+        -fvisibility=default \
+	$(PYTHON_CFLAGS)
+
+_journal_la_LDFLAGS = \
+	$(AM_LDFLAGS) \
+	-shared \
+	-module \
+	-avoid-version
+
+_journal_la_LIBADD = \
+	$(PYTHON_LIBS) \
+	libsystemd-journal.la
+
+dist_pkgpyexec_PYTHON = \
+	src/python-systemd/journal.py \
+	src/python-systemd/__init__.py
+
+endif
+
+# ------------------------------------------------------------------------------
+
 SED_PROCESS = \
 	$(AM_V_GEN)$(MKDIR_P) $(dir $@) && \
 	$(SED)	-e 's,@rootlibexecdir\@,$(rootlibexecdir),g' \

configure.ac

@@ -80,16 +80,31 @@ m4_ifdef([GOBJECT_INTROSPECTION_CHECK], [
 GOBJECT_INTROSPECTION_CHECK([1.31.1])
 ], [AM_CONDITIONAL([HAVE_INTROSPECTION], [false])])
 
-AC_CHECK_TOOL(OBJCOPY, objcopy)
-AC_CHECK_TOOL(STRINGS, strings)
-AC_CHECK_TOOL(GPERF, gperf)
+AC_PATH_TOOL(OBJCOPY, objcopy)
+AC_PATH_TOOL(STRINGS, strings)
+AC_PATH_TOOL(GPERF, gperf)
 if test -z "$GPERF" ; then
         AC_MSG_ERROR([*** gperf not found])
 fi
 
-# we use python only to build the man page index
+# we use python to build the man page index, and for systemd-python
+have_python=no
+have_python_devel=no
 AM_PATH_PYTHON(,, [:])
-AM_CONDITIONAL([HAVE_PYTHON], [test "$PYTHON" != :])
+if test "$PYTHON" != : ; then
+        have_python=yes
+        AC_PATH_PROG([PYTHON_CONFIG], python-config)
+
+        if test -n "$PYTHON_CONFIG" ; then
+                have_python_devel=yes
+                PYTHON_CFLAGS="`$PYTHON_CONFIG --cflags`"
+                PYTHON_LIBS="`$PYTHON_CONFIG --libs`"
+                AC_SUBST(PYTHON_CFLAGS)
+                AC_SUBST(PYTHON_LIBS)
+        fi
+fi
+AM_CONDITIONAL([HAVE_PYTHON], [test "$have_python" = "yes"])
+AM_CONDITIONAL([HAVE_PYTHON_DEVEL], [test "$have_python_devel" = "yes"])
 
 CC_CHECK_FLAGS_APPEND([with_cflags], [CFLAGS], [\
         -pipe \
@@ -803,6 +818,8 @@ AC_MSG_RESULT([
         gudev:                   ${enable_gudev}
         gintrospection:          ${enable_introspection}
         keymap:                  ${enable_keymap}
+        Python:                  ${have_python}
+        Python Headers:          ${have_python_devel}
 
         prefix:                  ${prefix}
         rootprefix:              ${with_rootprefix}

src/python-systemd/Makefile

@@ -0,0 +1 @@
+../Makefile

src/python-systemd/_journal.c

@@ -0,0 +1,137 @@
+#include <Python.h>
+
+#define SD_JOURNAL_SUPPRESS_LOCATION
+#include <systemd/sd-journal.h>
+
+#include "macro.h"
+
+PyDoc_STRVAR(journal_sendv__doc__,
+             "sendv('FIELD=value', 'FIELD=value', ...) -> None\n\n"
+             "Send an entry to the journal."
+             );
+
+static PyObject *
+journal_sendv(PyObject *self, PyObject *args) {
+    struct iovec *iov = NULL;
+    int argc = PyTuple_Size(args);
+    int i, r;
+    PyObject *ret = NULL;
+
+    PyObject **encoded = calloc(argc, sizeof(PyObject*));
+    if (!encoded) {
+        ret = PyErr_NoMemory();
+        goto out1;
+    }
+
+    // Allocate sufficient iovector space for the arguments.
+    iov = malloc(argc * sizeof(struct iovec));
+    if (!iov) {
+        ret = PyErr_NoMemory();
+        goto out;
+    }
+
+    // Iterate through the Python arguments and fill the iovector.
+    for (i = 0; i < argc; ++i) {
+        PyObject *item = PyTuple_GetItem(args, i);
+        char *stritem;
+        Py_ssize_t length;
+
+        if (PyUnicode_Check(item)) {
+            encoded[i] = PyUnicode_AsEncodedString(item, "utf-8", "strict");
+            if (encoded[i] == NULL)
+                goto out;
+            item = encoded[i];
+        }
+        if (PyBytes_AsStringAndSize(item, &stritem, &length))
+            goto out;
+
+        iov[i].iov_base = stritem;
+        iov[i].iov_len = length;
+    }
+
+    // Clear errno, because sd_journal_sendv will not set it by
+    // itself, unless an error occurs in one of the system calls.
+    errno = 0;
+
+    // Send the iovector to the journal.
+    r = sd_journal_sendv(iov, argc);
+
+    if (r) {
+        if (errno)
+            PyErr_SetFromErrno(PyExc_IOError);
+        else
+            PyErr_SetString(PyExc_ValueError, "invalid message format");
+        goto out;
+    }
+
+    // End with success.
+    Py_INCREF(Py_None);
+    ret = Py_None;
+
+out:
+    for (i = 0; i < argc; ++i)
+        Py_XDECREF(encoded[i]);
+
+    free(encoded);
+
+out1:
+    // Free the iovector. The actual strings
+    // are already managed by Python.
+    free(iov);
+
+    return ret;
+}
+
+PyDoc_STRVAR(journal_stream_fd__doc__,
+             "stream_fd(identifier, priority, level_prefix) -> fd\n\n"
+             "Open a stream to journal by calling sd_journal_stream_fd(3)."
+             );
+
+static PyObject*
+journal_stream_fd(PyObject *self, PyObject *args) {
+    const char* identifier;
+    int priority, level_prefix;
+    int fd;
+    if (!PyArg_ParseTuple(args, "sii:stream_fd",
+                          &identifier, &priority, &level_prefix))
+        return NULL;
+
+    fd = sd_journal_stream_fd(identifier, priority, level_prefix);
+    if (fd < 0)
+        return PyErr_SetFromErrno(PyExc_IOError);
+
+    return PyLong_FromLong(fd);
+}
+
+static PyMethodDef methods[] = {
+    {"sendv",  journal_sendv, METH_VARARGS, journal_sendv__doc__},
+    {"stream_fd", journal_stream_fd, METH_VARARGS,
+     journal_stream_fd__doc__},
+    {NULL, NULL, 0, NULL}        /* Sentinel */
+};
+
+#if PY_MAJOR_VERSION < 3
+
+PyMODINIT_FUNC
+init_journal(void)
+{
+    (void) Py_InitModule("_journal", methods);
+}
+
+#else
+
+static struct PyModuleDef module = {
+    PyModuleDef_HEAD_INIT,
+    "_journal", /* name of module */
+    NULL, /* module documentation, may be NULL */
+    0, /* size of per-interpreter state of the module */
+    methods
+};
+
+PyMODINIT_FUNC
+PyInit__journal(void)
+{
+    return PyModule_Create(&module);
+}
+
+#endif

src/python-systemd/journal.py

@@ -0,0 +1,93 @@
+import traceback as _traceback
+import os as _os
+from syslog import (LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR,
+                    LOG_WARNING, LOG_NOTICE, LOG_INFO, LOG_DEBUG)
+from ._journal import sendv, stream_fd
+
+def _make_line(field, value):
+    if isinstance(value, bytes):
+        return field.encode('utf-8') + b'=' + value
+    else:
+        return field + '=' + value
+
+def send(MESSAGE, MESSAGE_ID=None,
+         CODE_FILE=None, CODE_LINE=None, CODE_FUNC=None,
+         **kwargs):
+    r"""Send a message to journald.
+
+    >>> journal.send('Hello world')
+    >>> journal.send('Hello, again, world', FIELD2='Greetings!')
+    >>> journal.send('Binary message', BINARY=b'\xde\xad\xbe\xef')
+
+    Value of the MESSAGE argument will be used for the MESSAGE= field.
+
+    MESSAGE_ID can be given to uniquely identify the type of message.
+
+    Other parts of the message can be specified as keyword arguments.
+
+    Both MESSAGE and MESSAGE_ID, if present, must be strings, and will
+    be sent as UTF-8 to journal. Other arguments can be bytes, in
+    which case they will be sent as-is to journal.
+
+    CODE_LINE, CODE_FILE, and CODE_FUNC can be specified to identify
+    the caller. Unless at least on of the three is given, values are
+    extracted from the stack frame of the caller of send(). CODE_FILE
+    and CODE_FUNC must be strings, CODE_LINE must be an integer.
+
+    Other useful fields include PRIORITY, SYSLOG_FACILITY,
+    SYSLOG_IDENTIFIER, SYSLOG_PID.
+    """
+
+    args = ['MESSAGE=' + MESSAGE]
+
+    if MESSAGE_ID is not None:
+        args.append('MESSAGE_ID=' + MESSAGE_ID)
+
+    if CODE_LINE == CODE_FILE == CODE_FUNC == None:
+        CODE_FILE, CODE_LINE, CODE_FUNC = \
+            _traceback.extract_stack(limit=2)[0][:3]
+    if CODE_FILE is not None:
+        args.append('CODE_FILE=' + CODE_FILE)
+    if CODE_LINE is not None:
+        args.append('CODE_LINE={:d}'.format(CODE_LINE))
+    if CODE_FUNC is not None:
+        args.append('CODE_FUNC=' + CODE_FUNC)
+
+    args.extend(_make_line(key, val) for key, val in kwargs.items())
+    return sendv(*args)
+
+def stream(identifier, priority=LOG_DEBUG, level_prefix=False):
+    r"""Return a file object wrapping a stream to journal.
+
+    Log messages written to this file as simple newline sepearted
+    text strings are written to the journal.
+
+    The file will be line buffered, so messages are actually sent
+    after a newline character is written.
+
+    >>> stream = journal.stream('myapp')
+    >>> stream
+    <open file '<fdopen>', mode 'w' at 0x...>
+    >>> stream.write('message...\n')
+
+    will produce the following message in the journal:
+
+    PRIORITY=7
+    SYSLOG_IDENTIFIER=myapp
+    MESSAGE=message...
+
+    Using the interface with print might be more convinient:
+
+    >>> from __future__ import print_function
+    >>> print('message...', file=stream)
+
+    priority is the syslog priority, one of LOG_EMERG, LOG_ALERT,
+    LOG_CRIT, LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO, LOG_DEBUG.
+
+    level_prefix is a boolean. If true, kernel-style log priority
+    level prefixes (such as '<1>') are interpreted. See sd-daemon(3)
+    for more information.
+    """
+
+    fd = stream_fd(identifier, priority, level_prefix)
+    return _os.fdopen(fd, 'w', 1)