PR#404: add support for TEST_SSHD_USEDNS_NO - standard-test-roles

standard-test-roles

#404 add support for TEST_SSHD_USEDNS_NO

Merged 3 years ago by astepano. Opened 3 years ago by rmeggins.

rmeggins/standard-test-roles bootcmd-UseDNS-no into master

Rich Megginson • 3 years ago

88a6872

README.md

file modified

		`@@ -208,5 +208,12 @@`
		`If the number of hostaliases does not match the number of subjects, you will get`
		`an error.`

		`+ ## TEST_SSHD_USEDNS_NO`
		`+`
		+ Some EL7 systems have `sshd` configured with `UseDNS yes` by default. This will
		+ cause terrible performance with `ssh` and especially with Ansible. You can use
		+ `--sshd-usedns-no` or set `TEST_SSHD_USEDNS_NO=True` to configure the VM to use
		+ `UseDNS no` instead.
		`+`
		`[1]: https://fedoraproject.org/wiki/CI/Metadata`
		`[2]: http://fmf.readthedocs.io/`

inventory/standard-inventory-qcow2

file modified

+21

		`@@ -65,6 +65,17 @@`
		`DEF_USER = "root"`
		`DEF_PASSWD = "foobar"`
		`DEF_HOST = "127.0.0.3"`
		`+ # configure sshd to use UseDNS no to fix broken EL7 systems`
		`+ BOOTCMD_SSHD_USEDNS_NO = """bootcmd:`
		`+ - \|`
		`+ if grep -q '^UseDNS' /etc/ssh/sshd_config; then`
		`+ sed 's/^UseDNS.*$/UseDNS no/' -i /etc/ssh/sshd_config`
		`+ elif grep -q '^#UseDNS' /etc/ssh/sshd_config; then`
		`+ sed 's/^#UseDNS.*$/UseDNS no/' -i /etc/ssh/sshd_config`
		`+ else`
		`+ echo "UseDNS no" >> /etc/ssh/sshd_config`
		`+ fi`
		`+ """`
		`USER_DATA = """#cloud-config`
		`users:`
		`- default`
		`@@ -485,6 +496,8 @@`
		`userdata = os.path.join(directory, "user-data")`
		`with open(userdata, 'w') as f:`
		`f.write(USER_DATA)`
		`+ if opts.sshd_usedns_no:`
		`+ f.write(BOOTCMD_SSHD_USEDNS_NO)`
		`# Create our cloud init so we can log in`
		`cloudinit = os.path.join(directory, "cloud-init.iso")`
		`subprocess.check_call(["/usr/bin/genisoimage", "-input-charset", "utf-8",`
		`@@ -654,6 +667,13 @@`
		`--use-basename, then you do not have to use --hostalias for every subject.`
		`"""`

		`+`
		`+ def help_sshd_usedns_no():`
		`+ return """On some EL7 systems, sshd uses 'UseDNS yes' by default. This can`
		`+ create a very bad performance problem with ssh and Ansible. You can use`
		`+ --sshd-usedns-no to configure the VM to use 'UseDNS no' instead."""`
		`+`
		`+`
		`def main():`
		`global logger`
		`global diagnose`
		`@@ -683,6 +703,7 @@`
		`parser.add_argument('--host', help="Full path to qcow2 disk image")`
		`parser.add_argument("--use-basename", default=bool(distutils.util.strtobool(os.environ.get("TEST_USE_BASENAME", "False"))), action="store_true", help=help_hostalias())`
		`parser.add_argument("--hostalias", default=shlex.split(os.environ.get("TEST_HOSTALIASES", "")), action="append", help=help_hostalias())`
		`+ parser.add_argument("--sshd-usedns-no", default=bool(distutils.util.strtobool(os.environ.get("TEST_SSHD_USEDNS_NO", "False"))), action="store_true", help=help_sshd_usedns_no())`
		`parser.add_argument("subjects", nargs="*", default=shlex.split(os.environ.get("TEST_SUBJECTS", "")))`
		`opts = parser.parse_args()`
		`# Send logs to common logfile for all default provisioners.`

rmeggins commented 3 years ago

TEST_SSHD_USEDNS_NO

Some EL7 systems have sshd configured with UseDNS yes by default. This will
cause terrible performance with ssh and especially with Ansible. You can use
--sshd-usedns-no or set TEST_SSHD_USEDNS_NO=True to configure the VM to use
UseDNS no instead.

rebased onto 88a6872

3 years ago

nhosoi commented 3 years ago

lgtm

spetros commented 3 years ago

This fix works for me flawlessly. One question, shouldn't this be a default behavior for RHEL 7? Without adding TEST_SSHD_USEDNS_NO=True performance of rhel 7 VM is terrible.

rmeggins commented 3 years ago

This fix works for me flawlessly. One question, shouldn't this be a default behavior for RHEL 7? Without adding TEST_SSHD_USEDNS_NO=True performance of rhel 7 VM is terrible.

I think we need to add some sort of item to our config.json which will allow to specify environment variables for each image e.g.

    {
      "name": "rhel-7",
      ...
      "env": {
         "TEST_SSHD_USEDNS_NO": "True"
      }

we need something like this for el6 as well to set the ssh cipher parameters, which we definitely only want to set for el6:

    {
      "name": "rhel-6",
      ...
      "env": {
         "TEST_EXTRA_SSH_ARGS": "-o PubkeyAcceptedKeyTypes=+ssh-rsa"
      }

astepano commented 3 years ago

lgtm

astepano commented 3 years ago

@rmeggins please let me know when this PR can be merged.

rmeggins commented 3 years ago

@rmeggins please let me know when this PR can be merged.

It is ready to be merged

astepano commented 3 years ago

Commit 5bb8fc1 fixes this pull-request

Pull-Request has been merged by astepano

3 years ago

Pull-Request has been merged by astepano

3 years ago

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Changes Summary 2

inventory/standard-inventory-qcow2

standard-test-roles

Source Code

#404 add support for TEST_SSHD_USEDNS_NO Merged 3 years ago by astepano. Opened 3 years ago by rmeggins. rmeggins/standard-test-roles bootcmd-UseDNS-no into master

TEST_SSHD_USEDNS_NO

Metadata

Changes Summary 2

#404 add support for TEST_SSHD_USEDNS_NO

Merged 3 years ago by astepano. Opened 3 years ago by rmeggins.

rmeggins/standard-test-roles bootcmd-UseDNS-no into master