Not sure how to have this logic implemented, I know how to do it a single file :
- name: Obtain information about a file
win_stat:
path: "C:\myfile.txt"
register: fileinfo
- [...]
when: fileinfo.exists == False
how should I go with a list of files?
If you just want to reduce the steps for doing this, you should be able to do your download step (not shown in your example) with ignore_errors: yes on your download commands. If you use a combination of ignore_errors: yes and register, you can even tell whether the command failed.
If you're looking to make it a bit more efficient, you can do the stat in a single task and then examine the results of that. When you execute a task with a list, you get a hash of answers.
Assuming you have a list of file names/paths in ssh_key_config, you use the stat and then you can loop over the items (which conveniently have the file name in them).
- name: Check to see if file exists
stat:
path: "{{ remote_dir }}/{{ item }}"
register: stat_results
with_items: "{{ target_files }}"
ignore_errors: True
- name: perform operation
fetch:
src: "{{ remote_dir }}/{{ item.item }}"
dest: "{{ your_dest_dir }}"
flat: yes
with_items: "{{ stat_results.results }}"
when: item.stat.exists == False
In this case, the assumptions are that remote_dir contains the remote directory on the host, target_files contains the actual file names, and your_dest_dir contains the location you want the files placed locally.
I don't do much with Windows and Ansible, but win_stat is documented pretty much the same as stat, so you can likely just replace that.
Also note that this expects the list of files, not a glob. If you use a glob (for example, you want to retrieve all files with a certain extension from the remote), then you would not use the with_items clause, and you'd need to use the item.stat.filename and/or item.stat.path to retrieve the file remotely (since the item.item would contain the request item, which would be the glob.
Related
So, I have a playbook using a hosts file template to update or revert hosts files on 18 specific Linux VMs. The entry which goes at the end of the file looks like:
10.x.x.66 fooconnect
This above example would be on the 1st of 18 VMs, the 18th VM would look like:
10.x.x.83 fooconnect
Normally, that hostname resolves to a VIP. However, we found during some load testing that it may be beneficial to point each front-end VM to a back-end VM directly. So, my goal is to have a playbook that can update what the hostname resolves to with the above mentioned range, or revert it back to the VIP (reverting back is done using a template only--this part works fine).
What I am unsure about is how to implement this in Ansible. Is there a way to loop through the IPs using jinja2 template "for loops?" Or maybe using lineinfile with some loop magic?
Here is my Ansible role example. For the moment I am using a dirty shell command to create my IP list...open to suggestions for a better way to implement this.
- name: Add a line to a hosts file using a template
template:
src: "{{ srcfile }}"
dest: "{{ destfile }}"
owner: "{{ own_var }}"
group: "{{ grp_var }}"
mode: "{{ mode_var }}"
backup: yes
- name: Get the IPs
shell: "COUNTER=66;for i in {66..83};do echo 10.x.x.$i;((COUNTER++));done"
register: pobs_ip
- name: Add a line
lineinfile:
path: /etc/hosts
line: "{{item}} fooconnect" #Ideally would want "item" to just be one IP and not
insertafter: EOF #the entire list as it would be like this.
loop: "{{pobsips}}"
VARs file:
pobsips:
- "{{pobs_ip.stdout}}"
Instead of using a shell task, we can improvise it and create the range of IP addresses using set_fact with range. Once we have the range of IP addresses in a "list", we can loop lineinfile with that and achieve this.
Example:
- name: create a range of IP addresses in a variable my_range
set_fact:
my_range: "{{ my_range|default([]) + [ '10.1.1.' ~ item ] }}"
loop: "{{ range(66, 84)|list }}"
- name: Add a line to /etc/hosts
lineinfile:
path: /etc/hosts
line: "{{ item }} fooconnect"
insertafter: EOF
loop: "{{ my_range }}"
Updated answer:
There is another approach if we want to append only 1 line into the /etc/hosts file of each host with incrementing IP addresses.
For this we can use the ipmath of ipaddr filter to get the next IP address for given IP address.
Use ansible_play_hosts to get the list of hosts on which play is running
Set an index variable index_var and when condition to update file only when the ansible_hostname or inventory_hostname matches.
Run playbook serially and only once on a host per run using serial and run_once flags.
Let's consider an example inventory file like:
[group_1]
host1
host2
host3
host4
...
Then in playbook:
- hosts: group_1
serial: 1
vars:
start_ip: 10.1.1.66
tasks:
- name: Add a line to /etc/hosts
lineinfile:
path: "/tmp/hosts"
line: "{{ start_ip|ipmath(my_idx) }} fooserver"
insertafter: EOF
loop: "{{ ansible_play_hosts }}"
loop_control:
index_var: my_idx
run_once: true
when: item == inventory_hostname
I want to use content in .txt file and I tried to debug content using following code.
- name: Find .txt files
find:
paths: "{{output_path}}"
patterns: '*.txt,'
register: file_path
- name: Show content
debug:
msg: "{{lookup('file', item.path)}}"
with_items: "{{file_path.files}}"
But I got this error.
[WARNING]: Unable to find '/path/file.txt' in expected paths (use -vvvvv to see paths)
TASK [Show content] ******************************************************
fatal: [10.0.2.40]: FAILED! => {"msg": "An unhandled exception occurred
while running the lookup plugin 'file'. Error was a <class 'ansible.errors.AnsibleError'>,
original message: could not locate file in lookup: /path/file.txt"}
How I fix this error?
There's nothing inherently wrong with your playbook, except that you have a comma inside the find pattern (this might be just a typo, but you should check it out) if you are running this playbook locally. In the case that you are running this playbook on a remote server, you should try to use a different module like slurp or fetch.
slurp works great if you need to keep the contents of the txt in memory to use it on another task. Bear in mind that ansible will encode the slurp module's output in base64, so you should decode it first when you want to use it. From the module example page:.`
- name: Find out what the remote machine's mounts are
ansible.builtin.slurp:
src: /proc/mounts
register: mounts
- name: Print returned information
ansible.builtin.debug:
msg: "{{ mounts['content'] | b64decode }}"
You can verify what I am saying with the following example:
I tried replicating your situation locally. On a temporary folder, I run the following command to populate it with many .txt files:
echo {001..099} > file_{001..099}.txt
Then I wrote the same playbook that you provided:
#
# show_contents.yml
#
- hosts: localhost
gather_facts: no
tasks:
- name: Find .txt files
find:
paths: "{{ output_files }}"
patterns: "*.txt"
register: file_path
- name: Debug the file_path variable
debug:
var: file_path
- name: Get the contents of the files using debug
debug:
msg: "{{ lookup('file', item.path ) }}"
loop: "{{ file_path.files }}"
If you run this playbook, passing the appropriate output_files variable with --extra-vars, the playbook works fine.
ansible-playbook show_contents.yml --extra-vars "output_files=/tmp/ansible"
You'll see that the playbook runs without an issue. Try using this example to figure out what you are trying to achieve. And then modify the playbook to use some of the previously mentioned modules when working with remote servers.
Prior to Ansible 2.5, the syntax for loops used to be with_x. Starting at 2.5, loop is favored and with_x basically disappeared from the docs.
Still, the docs mention exemples of how to replace with_x with loop. But I'm clueless as to how we're now supposed to loop through a directory of files.
Let's say I need to upload all the files within a given dir, I used to use with_fileglob.
- name: Install local checks
copy:
src: "{{ item }}"
dest: /etc/sensu/plugins/
owner: sensu
group: sensu
mode: 0744
with_fileglob:
- plugins/*
So what's the modern equivalent? Is it even possible? I know I still can use with_fileglob but as I'm writing new roles, I'd better have them future-proof.
The equivalent is
loop: "{{ lookup('fileglob', 'plugins/*', wantlist=True) }}"
Here is the doc.
From the current Ansible loops doc:
Any with_* statement that requires using lookup within a loop should
not be converted to use the loop keyword. For example, instead of
doing:
loop: "{{ lookup('fileglob', '*.txt', wantlist=True) }}"
it’s cleaner to keep:
with_fileglob: '*.txt'
Essentially, I want to be able to handle "wildcard filenames" in Linux using ansible. In essence, this means using the ls command with part of a filename followed by an "*" so that it will list ONLY certain files.
However, I cannot store the output properly in a variable as there will likely be more than one filename returned. Thus, I want to be able to store these results no matter how many there might be in an array during one task. I then want to be able to retrieve all of the results from the array in a later task. Furthermore, since I don't know how many files might be returned, I cannot do a task for each filename, and an array makes more sense.
The reason behind this is that there are files in a random storage location that are changed often, but they always have the same first half. It's their second half of their names that are random, and I don't want to have to hard code that into ansible at all.
I'm not certain at all how to properly implement/manipulate an array in ansible, so the following code is an example of what I'm "trying" to accomplish. Obviously it won't function as intended if more than one filename is returned, which is why I was asking for assistance on this topic:
- hosts: <randomservername>
remote_user: remoteguy
become: yes
become_method: sudo
vars:
aaaa: b
tasks:
- name: Copy over all random file contents from directory on control node to target clients. This is to show how to manipulate wildcard filenames.
copy:
src: /opt/home/remoteguy/copyable-files/testdir/
dest: /tmp/
owner: remoteguy
mode: u=rwx,g=r,o=r
ignore_errors: yes
- name: Determine the current filenames and store in variable for later use, obviously for this exercise we know part of the filenames.
shell: "ls {{item}}"
changed_when: false
register: annoying
with_items: [/tmp/this-name-is-annoying*, /tmp/this-name-is-also*]
- name: Run command to cat each file and then capture that output.
shell: cat {{ annoying }}
register: annoying_words
- debug: msg=Here is the output of the two files. {{annoying_words.stdout_lines }}
- name: Now, remove the wildcard files from each server to clean up.
file:
path: '{{ item }}'
state: absent
with_items:
- "{{ annoying.stdout }}"
I understand the YAML format got a little mussed up, but if it's fixed, this "would" run normally, it just won't give me the output I'm looking for. Thus if there were 50 files, I'd want ansible to be able to manipulate them all, and/or be able to delete them all.. etc etc etc.
If anyone here could let me know how to properly utilize an array in the above test code fragment that would be fantastic!
Ansible stores the output of shell and command action modules in stdout and stdout_lines variables. The latter contains separate lines of the standard output in a form of a list.
To iterate over the elements, use:
with_items:
- "{{ annoying.stdout_lines }}"
You should remember that parsing ls output might cause problems in some cases.
Can you try as below.
- name: Run command to cat each file and then capture that output.
shell: cat {{ item.stdout_lines }}
register: annoying_words
with_items:
- "{{ annoying.results }}"
annoying.stdout_lines is already a list.
From doc of stdout_lines
When stdout is returned, Ansible always provides a list of strings, each containing one item per line from the original output.
To assign the list to another variable do:
..
register: annoying
- set_fact:
varName: "{{annoying.stdout_lines}}"
# print first element on the list
- debug: msg="{{varName | first}}"
I have several files on a server that I need to download from an ansible playbook, but because the connection has good chances of interruption I would like to check their integrity after download.
I'm considering two approaches:
Store the md5 of those files in ansible as vars
Store the md5 of those files on the server as files with the extension .md5. Such a pair would look like: file.extension and file.extension.md5.
The first approach introduces overhead in maintaining the md5s in ansible. So everytime someone adds a new file, he needs to make sure he adds the md5 in the right place.
But as an advantage, there is a solution for this, using the built in check from get_url action in conjunction with checksum=md5. E.g.:
action: get_url: url=http://example.com/path/file.conf dest=/etc/foo.conf checksum=md5:66dffb5228a211e61d6d7ef4a86f5758
The second approach is more elegant and the narrows the responsibility. When someone adds a new file on the server, he will make sure to add the .md5 as well and won't even need to use the ansible playbooks.
Is there a way to use the checksum approach to match the md5 from a file?
If you wish to go with your method of storing the checksum in files on the server, you can definitely use the get_url checksum arg to validate it.
Download the .md5 file and read it into a var:
- set_fact:
md5_value: "{{ lookup('file', '/etc/myfile.md5') }}"
And then when you download the file, pass the contents of md5_value to get_url:
- get_url:
url: http://example.com
dest: /my/dest/file
checksum: "md5:{{ md5_value }}"
force: true
Note that it is vital to specify a path to a file in dest; if you set this to a directory (and have a filename in url), the behavior changes significantly.
Note also that you probably need the force: true. This will cause a new file to download every time you run it. The checksum is only triggered when files are downloaded. If the file already exists on your host it won't bother to validate the sum of the existing file, which might not be desirable.
To avoid the download every time you could stat to see if the file already exists, see what its sum is, and set the force param conditionally.
- stat:
path: /my/dest/file
register: existing_file
- set_fact:
force_new_download: "{{ existing_file.stat.md5 != md5_value }}"
when: existing_file.stat.exists
- get_url:
url: http://example.com
dest: /my/dest/file
checksum: "md5:{{ md5_value }}"
force: "{{ force_new_download | default ('false') }}"
Also, if you are pulling the sums/artifacts from some sort of web server you can actually get the value of the sum right from the url without having to actually download the file to the host. Here is an example using a Nexus server that would host the artifacts and their sums:
- set_fact:
md5_value: "{{ item }}"
with_url: http://my_nexus_server.com:8081/nexus/service/local/artifact/maven/content?g=log4j&a=log4j&v=1.2.9&r=central&e=jar.md5
This could be used in place of using get_url to download the md5 file and then using lookup to read from it.
With the stat module:
- stat:
path: "path/to/your/file"
register: your_file_info
- debug:
var: your_file_info.stat.md5
The elegant solution will be using the below 3 modules provided by ansible itself
http://docs.ansible.com/ansible/stat_module.html
use the stat module to extract the md5 value and register it in a variable
http://docs.ansible.com/ansible/copy_module.html
while using the copy module to copy the file from the server, register the return value of md5 in another variable
http://docs.ansible.com/ansible/playbooks_conditionals.html
use this conditional module to compare the above 2 variables and print the results whether the file is copied properly or not
Another solution is to use url lookup (tested on ansible-2.3.1.0):
- name: Download
get_url:
url: "http://localhost/file"
dest: "/tmp/file"
checksum: "md5:{{ lookup('url', 'http://localhost/file.md5') }}"
Wrote an ansible module with the help of https://pypi.org/project/checksumdir
The module can be found here
Example:
- get_checksum:
path: path/to/directory
checksum_type: sha1/md5/sha256/sha512
register: checksum