dedicated-server-availability-watcher

A simple CLI/daemon tool polling dedicated server availability which optionally notifies.

Featured providers:

• Online.net, now known as "Scaleway Dedibox"
• OVH, now known as "OVH Cloud"
• Scaleway Elastic Metal

Featured notifiers :

• IFTTT WebHooks with json, or values
• And "simple" requests (a custom URL using either GET with query parameters, or POST/PUT with json)

Sample output for each provider

OVH

Inventory (i removed a bunch of line here where "..." are shown) :

Known servers:
1801sk12 (@fr,gra,rbx,sbg) N/A N/A
...
21adv01-mum (@ynm) ram-32g-ecc-3200 softraid-2x4000sa
...
21adv01 (@bhs,fra,gra,lon,rbx,sbg,waw) ram-32g-ecc-3200 softraid-2x6000sa
...
21game01-apac (@sgp) ram-64g-ecc-2400 softraid-2x500nvme
...
21game01 (@bhs,fra,gra,lon,sbg,waw) ram-64g-ecc-2666 softraid-2x500nvme
...
21hci01 (@bhs,fra,gra,lon,rbx,sbg,waw) ram-192g-ecc-2933 softraid-12x3840sas-1x3200nvme
...
22sk030 (@bhs,ca,fr,gra,rbx,sbg) ram-32g-1333 softraid-2x2000sa
...
22skgame01-apac (@sg,sgp) ram-32g-noecc-2133 hybridsoftraid-2x480ssd-1x4000sa
...
23risestorle01 (@bhs,fra,gra,lon,rbx,sbg,waw) ram-32g-ecc-2666 softraid-3x960nvme

Checking for some server type (without notifier) :

$ ... check ovh 22sk010 22sk020 22sk030
22sk030

# NOTE: here, only `22sk030` is **not** out of stock

Online

Inventory:

Known servers:
24006 (Core-2-M-SATA@DC3) 192GB 3x4TB
...
24262 (Core-3-M-SATA@DC3) 192GB 3x6TB
...
24104 (Core-7-M-I@DC2,DC5,AMS1) 192GB 2x1.92TBSSD_NVME
...
23981 (Pro-2-M-SATA@DC3) 32GB 2x2TB
...
24020 (Pro-3-L-SSD-160@DC3) 96GB 2x160GBSSD
...
21329 (Pro-7-M@DC2,DC5,AMS1) 64GB 2x960GBSSD_NVME
24241 (Pro-7-S@DC2,DC5,AMS1) 32GB 2x480GBSSD_NVME
24131 (Start-1-L@DC2,DC3) 16GB 2x1TB
...
23997 (Start-3-S-SSD@DC5) 4GB 1x250GBSSD
24140 (Store-1-L@DC3) 64GB 12x4TB
24250 (Store-1-S@DC2,DC3) 32GB 2x4TB
24244 (Store-2-L@DC3,DC5) 64GB 12x4TB
...
24254 (Store-4-L@DC3) 192GB 5x6TB
24191 (Store-4-M@DC3) 128GB 4x6TB
24011 (Store-4-XL@DC3,DC5) 96GB 24x500GBSSD
24033 (Store-4-XXL@DC3,DC5) 96GB 24x1TBSSD

Checking for some server type (without notifier) :

$ ... check online 21321 23984 23981 24021
23981

# NOTE: only 23981 was **not** is out of stock.

Scaleway

Inventory :

Known servers:
23bc9219-0b3a-459a-9eb6-738ebb64f3ab (EM-T510X-NVME) 1536G 20800G
bd757ca3-a71b-4158-9ef5-39436b6db2a4 (EM-L101X-SATA) 96G 12000G
a5065ba4-dde2-45f3-adec-1ebbb27b766b (EM-B112X-SSD) 192G 2000G
d1e32633-3b8a-488c-b1db-8afcc4cdb216 (EM-T210E-NVME) 2048G 7680G
67ca9c9c-2f4a-447d-8d6d-7d242382a4a3 (EM-B312X-SSD) 256G 2000G
ddaf8ba6-b2b2-4279-8af3-51930fb602f8 (EM-B212X-SSD) 256G 2000G
25dcf38b-c90c-4b18-97a2-6956e9d1e113 (EM-A210R-HDD) 16G 2000G
6ec5bbb2-8267-41cd-aaf6-d43ea1b59372 (EM-A315X-SSD) 64G 2000G
c5853302-63e4-40c7-a711-4a91629565c8 (EM-L105X-SATA) 96G 24000G
a204136d-656b-44b7-9735-88ca2f62cb1f (EM-L110X-SATA) 96G 48000G
5a505e81-5f6a-42bd-acec-0b290be92697 (EM-A410X-SSD) 64G 2000G
8c2cf291-a3d3-4dc5-967f-f498a088411d (EM-B111X-SATA) 192G 16000G
c753f736-fbb4-4689-ae93-623f9d08dce5 (EM-B211X-SATA) 256G 16000G
4635682e-a2ac-4dcd-8071-3deb051e7398 (EM-B311X-SATA) 256G 24000G

Checking for some server type (without notifier) :

$ ... check scaleway a5065ba4-dde2-45f3-adec-1ebbb27b766b 67ca9c9c-2f4a-447d-8d6d-7d242382a4a3
a5065ba4-dde2-45f3-adec-1ebbb27b766b

# NOTE: Here, `67ca9c9c-2f4a-447d-8d6d-7d242382a4a3` is absent because it is out of stock.

See Usage for the actual commands.

Differential notifications using stored hashes

The tool is designed to notify only if something changed when checking. As such, two designs are possible: a memory state and a resident daemon, or a run-once job triggered by cron-like tools, which store their states on disk. I chose the latter, and a writable directory must be provided.

This can be done with the --storage-dir (or -s) option of the check command. Here are some example use of the storage option :

... check AAA BBB CCC
# this writes states to the **working** directory. This means
# the directory which was in use when the binary has been invoked,
# and *not* the directory where the binary is stored.

... check -s /var/cache/dsaw AAA BBB CCC
# will write the state hash files into the /var/cache/dsaw,
# provided that it actually exists **and** is writable by
# the user running the program.
# The program will **not** create the directory by itself,
# nor set or fix permissions.
# At the very least, it verifies on startup that the specified
# directory can be reached and is readable.

... check --storage-dir /tmp
# will store all hash files directly in /tmp, which is crude
# but works, as the files are small and not many, and the
# only downside is that you could get spurious notifications
# on reboot as the /tmp directory is usually cleaned upon boot.

Compilation

Build for release :

cargo build --release

Then you will find the dedicated binary in target/release/

Docker

Build image :

docker build -t dsaw:latest .

The program is not a daemon, it does a single execution then exits, preserving system resources :

docker run -it --rm --name dsaw \
--mount type=volume,src=dsaw,dst=/home/dsaw \
... ADDITIONNAL MOUNT OPTIONS ... \
... ADDITIONNAL ENV VARIABLES ... \
dsaw:latest \
... DSAW COMMAND ....

For example, for OVH provider, using the email-sendmail notifier, and using a working host system's msmtp configuration, and looking for the availability of an inexpensive server, which should not be located in Canada (see OVH section documentation) :

docker run -it --rm --name dsaw \
--mount type=volume,src=dsaw,dst=/home/dsaw \
--mount type=bind,src=/etc/msmtprc,dst=/etc/msmtprc,readonly \
--env EMAIL_TO=your.email@example.org \
--env EMAIL_FROM=a@b.c \
--env OVH_EXCLUDE_DATACENTER=ca,bhs \
dsaw:latest \
provider check --notifier email-sendmail ovh 22sk011

Additional information :

• This creates the named volume dsaw to store the persisted "latest" state.
• This volume will not be removed on exit, so subsequent runs do not notify every time
• There is a very low quantity of information stored in this volume, and only two accesses per run.

Usage

$ dedicated-server-availability-watcher
Check and notify about dedicated servers availability

Usage: dedicated-server-availability-watcher.exe <COMMAND>

Commands:
provider  provider actions
notifier  notifier actions
help      Print this message or the help of the given subcommand(s)

Options:
-h, --help     Print help information
-V, --version  Print version information

Notifiers

Listing available notifiers :

$ dedicated-server-availability-watcher notifier list
Available notifiers:
- ifttt-webhook-json
- ifttt-webhook-values
- simple-get
- simple-post
- simple-put
- email-sendmail

Testing that a notifier works :

$ dedicated-server-availability-watcher notifier test NOTIFIER_NAME
Notification sent

Providers

Listing available providers :

$ dedicated-server-availability-watcher provider list
Available providers:
- online
- ovh
- scaleway

Listing a provider inventory :

$ dedicated-server-availability-watcher provider inventory PROVIDER_NAME [--all]
Working...
Known servers:
...
(list of server info, where first column is the SERVER_ID for the `check` function below)
(if you provide the `--all` option, servers in red color are unavailable)
(without the option, unavailable servers are simply not listed)
...

Checking a provider for a specific server type, with results to stdout :

$ dedicated-server-availability-watcher provider check PROVIDER_NAME SERVER_ID [SERVER_ID...]
...
(one line per available server id)
(no output if none available)
...

You can be notified of the result instead :

$ ... check PROVIDER_NAME SERVER_ID [SERVER_ID...] --notifier=NOTIFIER_NAME

Configuration

Every setting is passed through environment variables, which are described

simple-post

SIMPLE_URL="http://example.org/test.php"

A json payload is sent to the URL :

{
    "provider_name": "dummy_provider",
    "available_servers": [
        "foo_server",
        "bar_server",
        "baz_server"
    ]
}

The above payload is pretty-printed here, but it is sent in a compact form.

simple-put

Identical as simple-post, except a PUT method is used.

simple-get

Uses the same SIMPLE_URL environment variable as above.

Adds the following environment variables for query parameters :

SIMPLE_GET_PARAM_NAME_PROVIDER="provider"
SIMPLE_GET_PARAM_NAME_SERVERS="servers"

This results in GET query for the same test payload (previously shown in `simple-post) :

GET /test.php?servers=foo_server%2Cbar_server%2Cbaz_server&provider=dummy_provider

Here, the server type id are comma separated (, is encoded as %2C).

ifttt-webhook-json

IMPORTANT: an IFTTT account is required.

• Please create one beforehand if you do not already have one,
• Visit the Maker WebHook and click on Documentation,
• Take note of your api key at the top of the page.

Then visit IFTTT applets and :

• create an applet, click if
• select webhooks and Receive a web request with a JSON payload,
• enter an event name and take note of it, then click create,
• click then that
• select notifications for example and click Send a notification from the IFTTT app
• design the message as you want it, adding text ..
• where you want it to appear, click Add ingredient and select JsonPayload
• click create action, then continue then finish

Install the IFTTT smartphone app and login using your user account

Define the environment variables below :

IFTTT_WEBHOOK_EVENT=your_event_name
IFTTT_WEBHOOK_KEY=your_api_key

Test the notifier, you should get a notification.

The provided JsonPayload is the same as the one described in simple-post.

INFO: to delete an applet, visit the difficult-to-find page on IFTTT.

ifttt-webhook-values

Same as above, except that you must :

• choose Receive a web request when choosing webhooks when clicking if
• add Value1 and Value2 when clicking Add ingredient while selecting notifications

scaleway

IMPORTANT: a Scaleway account is required.

• Please create one beforehand if you do not already have one,
• Visit the Console
• Click on your user profile and select API Keys (link),
• Click on Generate API key and take note of it.

Define the environment variables below :

SCALEWAY_SECRET_KEY="your_api_key"
SCALEWAY_BAREMETAL_ZONES="fr-par-1,fr-par-2,nl-ams-1"

INFO: the zones variable is a comma , separated list of identifiers found in the official API documentation

Test the provider by listing its inventory.

email-sendmail

First of all, we use msmtp as sendmail provider. See the documentation for anything related. How to send email using msmtp it outside of the scope of this document and project.

You will first need to :

• to build a system-wide msmtprc yourself
• make sure it works : install msmtp, msmtp-mta, mailutils and test it using mail
• and make sure the PATH the user runs our program has access to sendmail, which often is located in sbin directories (which are not usually in non-root users' PATH) and that is because the library used to send emails only looks for sendmail in the provided PATH

Then you have to provide the required information :

• define an ENV EMAIL_FROM variable (which may be a dummy value like a@b.c as msmtpmay replace it by your account's email)
• define an ENV EMAIL_TO to where you want the email notifications to go

You can finally test it using :

dedicated-server-availability-watcher notifier test email-sendmail

If everything is setup correctly (and your provider does not do stupid antispam stuff) then you should receive a dummy email from your program.

ovh

No environment variable is required to query this particular API endpoint.

Test the provider by listing its inventory.

INFO, you can exclude datacenters from the inventory and the check :

OVH_EXCLUDE_DATACENTER=rbx,fr,ca,bhs

Where each value in the comma separated list will exclude :

• a specific datacenter (rbx, sbg, gra, bhs ...)
• the country of the datacenter (fr, ca, ...)

WARNING: excluding a country does not actually exclude its datacenters, you have to exclude both. That is strange, but that is how their api works. And as i have found no API entrypoint to list datacenters or country, i cannot separate both types to filter them out automatically.

And you can explore the official API and create an account if needed.