1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
#!/usr/bin/env python3
# =================================================================
#
# Authors: Ricardo Garcia Silva <ricardo.garcia.silva@gmail.com>
#
# Copyright (c) 2017 Ricardo Garcia Silva
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
#
# =================================================================
"""Entrypoint script for docker containers.
This module serves as the entrypoint for docker containers. Its main
purpose is to set up the pycsw database so that newly generated
containers may be useful soon after being launched, without requiring
additional input.
"""
import argparse
import logging
import os
import configparser
import sys
from time import sleep
from sqlalchemy import create_engine
from sqlalchemy.exc import OperationalError
from sqlalchemy.exc import ProgrammingError
from pycsw.core import admin
from pycsw.server import EnvInterpolation
logger = logging.getLogger(__name__)
def launch_pycsw(pycsw_config, workers=2, reload=False):
"""Launch pycsw.
Main function of this entrypoint script. It will read pycsw's config file
and handle the specified repository backend, after which it will yield
control to the gunicorn wsgi server.
The ``os.execlp`` function is used to launch gunicorn. This causes it to
replace the current process - something analogous to bash's `exec`
command, which seems to be a common techinque when writing docker
entrypoint scripts. This means gunicorn will become PID 1 inside the
container and it somehow simplifies the process of interacting with it
(e.g. if the need arises to restart the worker processes). It also allows
for a clean exit. See
http://docs.gunicorn.org/en/latest/signals.html
for more information on how to control gunicorn by sending UNIX signals.
"""
db_url = pycsw_config.get("repository", "database")
db = db_url.partition(":")[0].partition("+")[0]
db_handler = {
"sqlite": handle_sqlite_db,
"postgresql": handle_postgresql_db,
}.get(db)
logger.debug("Setting up pycsw's data repository...")
logger.debug("Repository URL: {}".format(db_url))
db_handler(
db_url,
pycsw_config.get("repository", "table"),
pycsw_config.get("server", "home")
)
sys.stdout.flush()
# we're using --reload-engine=poll because there is a bug with gunicorn
# that prevents using inotify together with python3. For more info:
#
# https://github.com/benoitc/gunicorn/issues/1477
#
args = ["--reload", "--reload-engine=poll"] if reload else []
execution_args = ["gunicorn"] + args + [
"--bind=0.0.0.0:8000",
"--access-logfile=-",
"--error-logfile=-",
"--workers={}".format(workers),
"pycsw.wsgi",
]
logger.debug("Launching pycsw with {} ...".format(" ".join(execution_args)))
os.execlp(
"gunicorn",
*execution_args
)
def handle_sqlite_db(database_url, table_name, pycsw_home):
db_path = database_url.rpartition(":///")[-1]
if not os.path.isfile(db_path):
try:
os.makedirs(os.path.dirname(db_path))
except OSError as exc:
if exc.args[0] == 17: # directory already exists
pass
admin.setup_db(database=database_url, table=table_name,
home=pycsw_home)
def handle_postgresql_db(database_url, table_name, pycsw_home):
_wait_for_postgresql_db(database_url)
try:
admin.setup_db(database=database_url, table=table_name,
home=pycsw_home)
except ProgrammingError:
pass # database tables are already created
def _wait_for_postgresql_db(database_url, max_tries=10, wait_seconds=3):
logger.debug("Waiting for {!r}...".format(database_url))
engine = create_engine(database_url)
current_try = 0
while current_try < max_tries:
try:
engine.execute("SELECT version();")
logger.debug("Database is already up!")
break
except OperationalError:
logger.debug("Database not responding yet ...")
current_try += 1
sleep(wait_seconds)
else:
raise RuntimeError(
"Database not responding at {} after {} tries. "
"Giving up".format(database_url, max_tries)
)
if __name__ == "__main__":
parser = argparse.ArgumentParser()
parser.add_argument(
"--workers",
default=2,
help="Number of workers to use by the gunicorn server. Defaults to 2."
)
parser.add_argument(
"-r",
"--reload",
action="store_true",
help="Should the gunicorn server automatically restart workers when "
"code changes? This option is only useful for development. "
"Defaults to False."
)
args = parser.parse_args()
config = configparser.ConfigParser(interpolation=EnvInterpolation())
config.read(os.getenv("PYCSW_CONFIG"))
try:
level = config.get("server", "loglevel").upper()
except configparser.NoOptionError:
level = "WARNING"
logging.basicConfig(level=getattr(logging, level))
launch_pycsw(config, workers=args.workers, reload=args.reload)
|
