Ansible源码分析之svn模块
Ansible的svn模块代码路径
/usr/lib/python2.6/site-packages/ansible/modules/core/source_control
模块使用：
# ansible localhost -m subversion -a "repo=https://code.svn.com/project1/patch_04 dest=~/test username=test password=test123 export=yes force=yes"
-m subversion表示指定subversion模块，这里的模块名称都是modules目录下的脚本名称
-a 指定模块参数，每个模块的参数不同
repo 指定svn的URL
dest 指定代码checkout或者export的绝对路径
username 指定用户名
password 指定密码
export 指定导出而不是checkout或者update
force 强制执行
如果执行过程有以下错误
"msg": "svn: Can't convert string from 'UTF-8' to native encoding:\nsvn: /root/john/test/web/WebRoot/html/?\\230?\\181?\\160?\\239?\\189?\\135?\\230?\\130?\\138",
解决办法就是：
将系统的字符编号和ansible的字符编号都设置成en_US.UTF-8
# echo $LANG en_US.UTF-8 # cat /etc/ansible/ansible.cfg|grep module_lang module_lang = en_US.UTF-8
同时在subversion.py中设置的默认字符编码就是C
os.environ['LANG'] = 'C'
class Subversion(object): def __init__( self, module, dest, repo, revision, username, password, svn_path): self.module = module self.dest = dest self.repo = repo self.revision = revision self.username = username self.password = password self.svn_path = svn_path
定义一个Python类Subversion和一些类参数
def _exec(self, args): bits = [ self.svn_path, '--non-interactive', '--trust-server-cert', '--no-auth-cache', ] if self.username: bits.extend(["--username", self.username]) if self.password: bits.extend(["--password", self.password]) bits.extend(args) rc, out, err = self.module.run_command(bits, check_rc=True) return out.splitlines()
定义类函数_exec，调用module_utils/basic.py中的run_command 函数
def checkout(self):
'''Creates new svn working directory if it does not already exist.'''
self._exec(["checkout", "-r", self.revision, self.repo, self.dest])
def export(self, force=False):
'''Export svn repo to directory'''
cmd = ["export"]
if force:
cmd.append("--force")
cmd.extend(["-r", self.revision, self.repo, self.dest])
self._exec(cmd)
定义checkout和export函数，分别执行svn checkout 或者svn export
def switch(self): '''Change working directory's repo.''' # switch to ensure we are pointing at correct repo. self._exec(["switch", self.repo, self.dest]) def update(self): '''Update existing svn working directory.''' self._exec(["update", "-r", self.revision, self.dest]) def revert(self): '''Revert svn working directory.''' self._exec(["revert", "-R", self.dest]) def get_revision(self): '''Revision and URL of subversion working directory.''' text = '\n'.join(self._exec(["info", self.dest])) rev = re.search(r'^Revision:.*$', text, re.MULTILINE).group(0) url = re.search(r'^URL:.*$', text, re.MULTILINE).group(0) return rev, url
定义svn switch, svn update,svn revert,svn get_revision相关的函数
def has_local_mods(self):
'''True if revisioned files have been added or modified. Unrevisioned files are ignored.'''
lines = self._exec(["status", self.dest])
# Match only revisioned files, i.e. ignore status '?'.
regex = re.compile(r'^[^?]')
# Has local mods if more than 0 modifed revisioned files.
return len(filter(regex.match, lines)) > 0
def needs_update(self):
curr, url = self.get_revision()
out2 = '\n'.join(self._exec(["info", "-r", "HEAD", self.dest]))
head = re.search(r'^Revision:.*$', out2, re.MULTILINE).group(0)
rev1 = int(curr.split(':')[1].strip())
rev2 = int(head.split(':')[1].strip())
change = False
if rev1 < rev2:
change = True
return change, curr, head
两个函数执行svn status 和svn info
def main():
module = AnsibleModule(
argument_spec=dict(
dest=dict(required=True),
repo=dict(required=True, aliases=['name', 'repository']),
revision=dict(default='HEAD', aliases=['rev', 'version']),
force=dict(default='no', type='bool'),
username=dict(required=False),
password=dict(required=False),
executable=dict(default=None),
export=dict(default=False, required=False, type='bool'),
),
supports_check_mode=True
)
dest = os.path.expanduser(module.params['dest'])
repo = module.params['repo']
revision = module.params['revision']
force = module.params['force']
username = module.params['username']
password = module.params['password']
svn_path = module.params['executable'] or module.get_bin_path('svn', True)
export = module.params['export']
os.environ['LANG'] = 'C'
svn = Subversion(module, dest, repo, revision, username, password, svn_path)
if export or not os.path.exists(dest):
before = None
local_mods = False
if module.check_mode:
module.exit_json(changed=True)
if not export:
svn.checkout()
else:
svn.export(force=force)
elif os.path.exists("%s/.svn" % (dest, )):
# Order matters. Need to get local mods before switch to avoid false
# positives. Need to switch before revert to ensure we are reverting to
# correct repo.
if module.check_mode:
check, before, after = svn.needs_update()
module.exit_json(changed=check, before=before, after=after)
before = svn.get_revision()
local_mods = svn.has_local_mods()
svn.switch()
if local_mods:
if force:
svn.revert()
else:
module.fail_json(msg="ERROR: modified files exist in the repository.")
svn.update()
else:
module.fail_json(msg="ERROR: %s folder already exists, but its not a subversion repository." % (dest, ))
if export:
module.exit_json(changed=True)
else:
after = svn.get_revision()
changed = before != after or local_mods
module.exit_json(changed=changed, before=before, after=after)
# import module snippets
from ansible.module_utils.basic import *
main()
这里就是svn模块的main函数，先判断是export还是checkout，再判断dest指定的目录是否存在，再判断版本有没有更新
参考文档：
https://github.com/ansible/ansible/issues/6737#ref-commit-42aa6ff