Utilizing timestamps within filenames

[Joe Louthan]

Hello,

In my deployments, I tend to do db backups and dump them into filenames containing a timestamp like so:

mysqldump dbname | gzip -9c > ~/dbname.`date +%Y-%m-%d.%H%M`.sql.gz ; ls -la ~/ | grep `date +%Y-%m-%d`

As you can see, when the dump is done, I want to see the resulting file just to eyeball it and make everything looks right.

(To answer future questions: we date time stamp our backup files so that we can keep them for an extended period of time.)

I would like to write something like this:

- hosts: dbserver

  remote_user: jlouthan

  tasks:

      - name: Backup Prod Database

        shell: mysqldump dbdump | gzip -9c > ~jlouthan/dbdump.`date +%Y-%m-%d`.sql.gz

        become: yes

        become_method: sudo

      - name: Check to see if the dbdump has been successfully created
        wait_for: path=~jlouthan/dbdump.`date +%Y-%m-%d`.sql.gz

Is there any chance that Ansible would be able to pick up on backticks or is there a better way?

[Felix Fontein]

Hi Joe,

you could add a task

- name: Get current timestamp
local_action: command bash -c "date +%Y-%m-%d.%H%M"
register: now
run_once: true

(or something similar adapted to your local environment) before your
dump task and then use {{ now }} in the next tasks to always get the
same timestamp.

Best,
Felix

[Brian Coca]

You can use a lookup or create a var based on it:

​datestring: ​"{{lookup('pipe', "date +%Y-%m-%d.%H%M")}}"

----------

Brian Coca

[Johannes Kastl]

On 21.04.16 17:45 Joe Louthan wrote:
> Is there any chance that Ansible would be able to pick up on backticks or
> is there a better way?

Apart form the other answers, I avoid using backticks and use the
$(date ...) syntax instead (a leading dollar sign and brackets instead
of backticks). Have you tried this?

Johannes

[Brian Coca]

$() depends on shell, I prefer it as it is stackable and cleaner than the backticks, but not always available.

----------

Brian Coca

[Joe Louthan]

I ran this:

- hosts: dbserver

  remote_user: jlouthan

  tasks:

      - name: Get current timestamp

        local_action: command bash -c "date +%Y-%m-%d.%H%M"

        register: timestamp

        run_once: true

      - debug: var=timestamp.stdout

      - name: Get current datestamp

        local_action: command bash -c "date +%Y-%m-%d"

        register: datestamp

        run_once: true

      - debug: var=datestamp.stdout

      - name: Backup Stag Database

        mysql_db: state=dump name=dbname target=~jlouthan/dbname.{{ datestamp }}.sql

become: yes

        become_method: sudo

- name: See the the Stag DB backup

shell: ls -la ~jlouthan/ | grep {{ timestamp }}

register: dumpstag

      - debug: var=dumpstag.stdout_lines

      - name: Make sure that the Stag DB Backups look good before you continue

        pause:

And got this:

[jlouthan@ansible-server Playbooks]$ ansible-playbook test-backup-Client-staging-db.yml

SUDO password:

PLAY [dbserver] **************************************************************

GATHERING FACTS ***************************************************************

ok: [dbserver]

TASK: [Get current timestamp] *************************************************

changed: [dbserver -> 127.0.0.1]

TASK: [debug var=timestamp.stdout] ********************************************

ok: [dbserver] => {

    "var": {

        "timestamp.stdout": "2016-04-22.1507"

    }

}

TASK: [Get current datestamp] *************************************************

changed: [dbserver -> 127.0.0.1]

TASK: [debug var=datestamp.stdout] ********************************************

ok: [dbserver] => {

    "var": {

        "datestamp.stdout": "2016-04-22"

    }

}

TASK: [Backup Stag Database] **************************************************

failed: [dbserver] => {"failed": true}

msg: this module requires key=value arguments (['state=dump', 'name=dbname', 'target=~jlouthan/dbname.{changed:', 'True,', 'end:', '2016-04-22 15:07:30.816204,', 'stdout:', '2016-04-22,', 'cmd:', '[bash,', '-c,', 'date +%Y-%m-%d],', 'rc:', '0,', 'start:', '2016-04-22 15:07:30.810278,', 'stderr:', ',', 'delta:', '0:00:00.005926,', 'invocation:', '{module_name:', 'ucommand,', 'module_complex_args:', '{},', 'module_args:', 'ubash -c "date +%Y-%m-%d"},', 'stdout_lines:', '[2016-04-22],', 'warnings:', '[]}.sql'])

FATAL: all hosts have already failed -- aborting

PLAY RECAP ********************************************************************

           to retry, use: --limit @/home/jlouthan/test-backup-Client-staging-db.retry

dbserver                  : ok=5    changed=2    unreachable=0    failed=1

What am I doing wrong?

[Brian Coca]

that the module name in the error is 'ucommand' and the spacing you posted, lends me to believe you are not matching the error to the actual play.

----------

Brian Coca

[Felix Fontein]

Hi Joe,

> I ran this:
> - hosts: dbserver
> remote_user: jlouthan
> tasks:
> - name: Get current timestamp
> local_action: command bash -c "date +%Y-%m-%d.%H%M"
> register: timestamp
> run_once: true
>
> - debug: var=timestamp.stdout

as you correctly note here, the variable you need is not timestamp, but
timestamp.stdout.

(I forgot the .stdout in my original mail.)

> - name: Backup Stag Database
> mysql_db: state=dump name=dbname target=~jlouthan/dbname.{{
> datestamp }}.sql

Here you have to write {{ datestamp.stdout }} instead of
{{ datestamp }}; otherwise, instead of just the datestamp, the whole
dict will be appended, which results in the error message you get below.

> TASK: [Backup Stag Database]
> **************************************************
> failed: [dbserver] => {"failed": true}
> msg: this module requires key=value arguments (['state=dump',
> 'name=dbname', 'target=~jlouthan/dbname.{changed:', 'True,', 'end:',
> '2016-04-22 15:07:30.816204,', 'stdout:', '2016-04-22,', 'cmd:',
> '[bash,', '-c,', 'date +%Y-%m-%d],', 'rc:', '0,', 'start:',
> '2016-04-22 15:07:30.810278,', 'stderr:', ',', 'delta:',
> '0:00:00.005926,', 'invocation:', '{module_name:', 'ucommand,',
> 'module_complex_args:', '{},', 'module_args:', 'ubash -c "date
> +%Y-%m-%d"},', 'stdout_lines:', '[2016-04-22],', 'warnings:',
> '[]}.sql'])

Here you can see that {{ datestamp }} was replaced by:

{changed:', 'True,', 'end:', '2016-04-22 15:07:30.816204,', 'stdout:',
'2016-04-22,', 'cmd:', '[bash,', '-c,', 'date +%Y-%m-%d],', 'rc:',
'0,', 'start:', '2016-04-22 15:07:30.810278,', 'stderr:', ',',
'delta:', '0:00:00.005926,', 'invocation:', '{module_name:',
'ucommand,', 'module_complex_args:', '{},', 'module_args:', 'ubash -c
"date +%Y-%m-%d"}

which is NOT what you want :)

Best,
Felix

--
Felix Fontein -- fe...@fontein.de -- https://felix.fontein.de/

[Joe Louthan]

That's it! Thank you!

To avoid being "that guy", here is the working playbook:

---

- hosts: dbserver

  remote_user: jlouthan

  tasks:

      - name: Get current timestamp

        local_action: command bash -c 'date +%Y-%m-%d.%H%M'

        # Consider switch this to a shell module with date command

        register: timestamp

        run_once: true

      - debug: var=timestamp.stdout

      - name: Get current datestamp

        local_action: command bash -c 'date +%Y-%m-%d'

        # Consider switch this to a shell module with date command

        register: datestamp

        run_once: true

      - debug: var=datestamp.stdout

      - name: Backup dbname Database

        mysql_db: "state=dump name=dbname target=~jlouthan/dbname.{{ timestamp.stdout }}.sql"

        become: yes

        become_method: sudo

      - name: See the DB Backups

        shell: ls -la ~jlouthan/ | grep {{ datestamp.stdout }}

        register: dumpdb

      - debug: var=dumpdb.stdout_lines

      - name: Make sure that the dbname DB Backups look good before you continue

        pause:

This playbook:

1. Gets current date and time stamps from the remote machine (as oppose to the local machine that is running Ansible. Something to keep in mind if you have servers in different timezones) - Note: the debug lines for date and time stamps are merely there for me to see what stamp should I be seeing 
2. Backup database using the timestamp within the resulting file name
3. Double check using just the datestamp (as oppose to the fulltime stamp) and making sure that the backup looks good

[Matt Martz]

Also, just as an FYI, this can be achieved without calling the date command:

---

- hosts: all

  tasks:

    - set_fact:

        datestamp: "{{ ansible_date_time.date }}"

        timestamp: "{{ '%s.%s%s'|format(ansible_date_time.date, ansible_date_time.hour, ansible_date_time.minute) }}"

    - debug:

        msg: "{{ item }}"

      with_items:

        - "{{ datestamp }}"

        - "{{ timestamp }}"

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