I must also add that I've got a central group_vars/all file from which I
pull all the variables like region, instance types, environment specific
load balancer names, etc.
On Wednesday, 29 October 2014 04:02:19 UTC-5, Sankalp Khare wrote:
>
> Hi Renaud,
>
> I totally get what you are looking to achieve. Perhaps you've achieved it
> already in the past year. Assuming that you are happy with specifying a start
> index = x and a count = N to produce machines with names containing x,
> x+1, x+2, ... x+N, I think the following playbook example will be
> instructive. I had the same requirement and this is what I was able to
> produce:
>
> # ansible-playbook create-web.yml --extra-vars "count=n startindex=x
> env=production"
> # provisions n web servers in prod env with indices x, x+1, x+2, ... x+n
>
> ---
> - name: "create and provision web servers in {{ env }} environment"
> hosts: localhost
> gather_facts: False
> tasks:
> - name: launch instances
> local_action:
> module: ec2
> key_name: "{{ launch_key.ec2_classic }}"
> instance_type: "{{ instance.web[env] }}"
> volumes:
> - device_name: /dev/sda1
> volume_size: 512
> delete_on_termination: true
> - device_name: "{{ ephemeral[0] }}"
> ephemeral: ephemeral0
> - device_name: "{{ ephemeral[1] }}"
> ephemeral: ephemeral1
> # ephemerals are deleted by default on termination
> region: "{{ region }}"
> image: "{{ os.amazon.ami_id }}"
> wait: yes
> group: "web-{{ env }}"
> count: "{{ count }}"
> wait_timeout: 1000
> register: created
> tags:
> - create
>
> - name: write instance ids and public dns of the instances to local
> hosts file
> local_action:
> module: lineinfile
> dest: ./hosts
> line: "{{ item.id }} {{ item.public_dns_name }}"
> create: yes
> with_items: created.instances
> tags:
> - create
>
> - name: create identifier sequence for tagging
> debug: msg="{{ item }}"
> with_sequence: start="{{ startindex }}" count="{{ count }}"
> format=%02d
> no_log: true # mute output
> register: sequence
> tags:
> - tag
>
> - name: tag instances
> no_log: true
> local_action: >-
> ec2_tag
> resource={{ item.0.id }}
> region={{ region }}
> args:
> tags:
> Name: "Web {{ env|title }} {{ item.1.msg }}"
> Env: "{{ env }}"
> Type: server
> Function: web
> OS: "{{ os.amazon.name }}"
> Region: "{{ region }}"
> ID: "{{ item.1.msg }}"
> with_together:
> - created.instances
> - sequence.results
> tags:
> - tag
>
> - name: update dns records
> route53: >-
> command=create
> zone=yoursite.com
> record=web.{{ item.1.msg }}.{{ env }}.server.yoursite.com
> type=CNAME
> ttl=300
> value={{ item.0.public_dns_name }}
> overwrite=true
> with_together:
> - created.instances
> - sequence.results
> tags:
> - deploy
>
> - name: register instances with load balancers
> local_action: ec2_elb
> args:
> instance_id: "{{ item.id }}"
> ec2_elbs: "{{ elb_names.web[env] }}"
> region: "{{ region }}"
> state: present
> wait: no
> with_items: created.instances
> tags:
> - deploy
>
> - name: add instances to an in-memory group
> no_log: true
> local_action: add_host hostname="{{ item.public_dns_name }}"
> groupname=fresh
> with_items: created.instances
> tags:
> - create
>
> - name: wait for ssh to come up
> local_action: wait_for host="{{ item.public_dns_name }}" port=22
> delay=60 timeout=320 state=started
> with_items: created.instances
> tags:
> - create
>
> - name: provision the instances
> hosts: fresh
> user: "{{ os.amazon.user }}"
> vars:
> user: "{{ os.amazon.user }}"
> roles:
> - common
> - swap
> - python
> tags:
> - configure
>
> - name: summary of created instances
> hosts: fresh
> gather_facts: false
> sudo: no
> tasks:
> - name: Get instance ec2 facts
> action: ec2_facts
> no_log: true # mute output
> register: ec2_facts
> - name: Get resource tags from ec2 facts
> sudo: false
> no_log: true # mute output
> local_action: >-
> ec2_tag
> resource={{ ec2_facts.ansible_facts.ansible_ec2_instance_id }}
> region={{ region }}
> state=list
> register: ec2_tags
> - debug: msg="{{ ec2_facts.ansible_facts.ansible_ec2_instance_id }}
> | {{ ec2_facts.ansible_facts.ansible_ec2_instance_type }} | {{
> ec2_tags.tags.Name }} | {{
> ec2_facts.ansible_facts.ansible_ec2_public_hostname }}"
> tags:
> - create
>
>
> Yes, parts of it are *very* contrived, but it gets the job done the way I
> want it to.
>
> @Others: Yes, the cattle model is the way to go, but while we're getting
> there, ansible must still do what we want. And thus continue our Sisyphian
> labours ;)
>
> On Wednesday, 27 November 2013 11:36:12 UTC-6, Renaud Guerin wrote:
>
> Nice tool !
>
> But your ssh example shows how a unique name is still unavoidable
> sometimes, be it Tags or DNS based.
>
> If I left instances with their EC2 birth names, I couldn’t just make up «
> ansible-ec2 ssh --name web1 » when I need to log into a web server, I’d
> have to « ansible-ec2 list » first with a raw group name to find web
> servers, then pick one and ssh into it.
>
> Also, some tools just rely on a nice hostname being set (the New Relic
> server dashboard would be unreadable with ec2-xxxx host names all mixed up)
> RabbitMQ for instance, names its task queues after the current hostname
> and warns against changing it. I know it’s bad practice and not autoscaling
> friendly, but it’s just how it is in some occasions.
>
> So, I’ll forget about CNAMEs in Route53 but I think my original feature
> request is still relevant : being able to pass a list of names to the EC2
> module to be added to the Name tag of each created instance.
> If I submitted such a patch, would you guys merge it ?
>
>
> On 27 novembre 2013 at 16:38:31, Peter Sankauskas ([email protected])
> wrote:
>
> Actually yes. You can tag AWS resources and find them using tags. For
> example, an Amazon Linux instance with tag Name=foo could be SSHed into
> using
>
> ansible-ec2 ssh --name foo -u ec2-user
>
>
> You can find the code here:
>
> https://github.com/pas256/ansible-ec2
>
>
> It uses Ansible's EC2 inventory plugin to do the lookup of public DNS name
> (or whatever you configure it to).
>
> One further tip. In a distributed environment, debugging can be tough
> because you don't know which server is causing issues. Get all of the
> logging out of the instances and into some central and searchable location.
> There are plenty of SaaS providers (Loggly, Splunk, Sumologic, Papertrail)
> and open source (logstash, etc) options available.
>
> --
> Kind regards,
> Peter Sankauskas
> Answers for AWS <http://answersforaws.com>
>
>
>
> On Wednesday, November 27, 2013 6:48:35 AM UTC-8, Renaud Guerin wrote:
>
> Hi Peter,
>
> Very interesting talk and this is probably the better approach, thanks.
>
> You do need to address individual servers from time to time though :
> ssh’ing into them to debug something, for instance.
>
> In this case, finding and copying the public_dns_name for a box sounds
> like a pain, and a big usability regression from a human-readable naming
> convention and DNS CNAMEs.
>
> Am I missing a clever way to use ansible to provide « vagrant ssh »
> functionality basically ?
> Or do you know of any wrapper tools to do something similar ?
>
> Just to belabor the point:
>
> https://www.youtube.com/watch?v=lQUdjPBJX5c
>
>
>
> On Sunday, November 24, 2013 10:34:39 AM UTC-8, Peter Sankauskas wrote:
>
> Hi Renaud,
>
> People that have been using AWS for a while don't really use it this way,
> or at least, they shouldn't. Treat servers like cattle, not pets.
>
> If you haven't yet, take a look at AutoScaling Groups:
>
> http://aws.amazon.com/autoscaling/
> <http://www.google.com/url?q=http%3A%2F%2Faws.amazon.com%2Fautoscaling%2F&sa=D&sntz=1&usg=AFQjCNHbyMw92ut0c-QkheWMVy34vCXxgw>
>
> ... and think about how to architect your application to run on dynamic
> infrastructure.
>
> --
> Kind regards,
> Peter Sankauskas
> Answers for AWS
> <http://www.google.com/url?q=http%3A%2F%2Fanswersforaws.com&sa=D&sntz=1&usg=AFQjCNFQbg6M0Bmr2rMpccgv3xl_aiQukg>
>
>
>
>
>
> On Saturday, November 23, 2013 8:55:34 AM UTC-8, Renaud Guerin wrote:
>
> Thanks Michael,
>
> I know (and mentioned) I’ll need to use the route53 module, that’s not
> the difficulty here.
> I did some more research and it looks like ‘with_together' is what I was
> looking for.
>
> If anyone is looking to do the same (it's a quite common provisioning
> pattern) :
>
> - provide an « instances_names » list
> - create the required number of instances using the ec2 module, register
> the result.
> - Use ec2_tag, add_host and route53 for, respectively: setting the AWS
> Name tag, adding the host to the inventory with its desired hostname (not
> the default EC2 name), adding a CNAME DNS entry for hostname -> EC2
> public_dns_name
> -For each of the modules above, use « with_together » to iterate
> through both the created instances list (returned by the EC2 module), and
> the hostnames list you provided.
>
> This would be slightly easier if the ec2 module would take an optional
> « instances_names » list as a parameter; and used it to set different EC2
> Name tags for each of the created instances.
> I can look at adding this functionality if it’s likely to be accepted and
> merged in. What do you think ?
>
>
> On 23 novembre 2013 at 16:38:27, Michael DeHaan ([email protected])
> wrote:
>
> http://ansibleworks.com/docs/modules.html#route53
> <http://www.google.com/url?q=http%3A%2F%2Fansibleworks.com%2Fdocs%2Fmodules.html%23route53&sa=D&sntz=1&usg=AFQjCNFTh6HnQAujtPzc-rzPWZkkzhvrKw>
>
>
> On Thu, Nov 21, 2013 at 2:14 PM, Renaud Guérin <[email protected]>
> wrote:
>
> On 21 novembre 2013 at 18:47:46, James Tanner ([email protected]) wrote:
>
> > The EC2 module's docs show how to create several instances at once
> > using the "count" variable, and register the results into another
> > variable ("ec2").
> >
> > You can then iterate on the created instances and do stuff (like add
> > them to an inventory group) using "with_items: ec2.instances"
> >
> > However, I can't figure out how to do the following :
> >
> > 1) Have the user provide a "names" list ( { "web1", "web2", "web3" }
> > ). Or better yet, a naming prefix ("web"), a count (3) and a start
> > index (1).
> > 2) Create them using the ec2 module, register results into "ec2" to
> > keep precious info like ec2.instances.public_dns_name.
> > 3) Here's the tricky bit : add a route53 DNS entry that CNAMEs
> > together each entry in the "names" list with the public_dns_name
> > values in "ec2.instances".
>
> Can you give an example for what you are trying to convey here? I'm a
> bit confused.
>
> Thanks for replying James,
>
> I’m trying to create a fleet of (for instance) web servers on EC2, and
> would like to give them meaningful ansible hostnames (web1, web2, etc)
> instead of the AWS generated public DNS names (
> ec2-xxxxx.compute-1.amazonaws.com
> <http://www.google.com/url?q=http%3A%2F%2Fec2-xxxxx.compute-1.amazonaws.com&sa=D&sntz=1&usg=AFQjCNFQ3DgG9MKPa_vN9SR9cR3eHWeSTA>
> )
>
> I’d also like to create a CNAME DNS record (using the route53 module)
> pointing their chosen name (web1, web2, etc) to the EC2 DNS record (
> ec2-xxxxx.compute-1.amazonaws.com
> <http://www.google.com/url?q=http%3A%2F%2Fec2-xxxxx.compute-1.amazonaws.com&sa=D&sntz=1&usg=AFQjCNFQ3DgG9MKPa_vN9SR9cR3eHWeSTA>).
>
> The latter is accessible in the « instances.public_dns_name »
>
> Ideally, I would just need to provide the ec2 module with a list of
> hostnames for the instances it’s going to create (internally it just needs
> to set the « Name » EC2 tag), and I’d get back the « item.hostname »
> (web1,web2) alongside each « item.public_dns_name » (
> ec2-xxxxx.compute-1.amazonaws.com
> <http://www.google.com/url?q=http%3A%2F%2Fec2-xxxxx.compute-1.amazonaws.com&sa=D&sntz=1&usg=AFQjCNFQ3DgG9MKPa_vN9SR9cR3eHWeSTA>)
>
> when using "with_items: ec2"
>
> The more I think of it, the more it sounds like just a few changes are
> needed in the ec2 module. I can try and have a go at it, but I’d like to
> know if there’s something similar already.
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