terribleplan/cfha
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

initial commit

Browse source
This commit is contained in:
Kegan Myers 2015-08-21 12:27:26 -05:00
commit 619bb2e023
16 changed files with 1067 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
.gitignore vendored Normal file
View file

@ -0,0 +1,2 @@
config.json
main

13
LICENSE Normal file
View file

@ -0,0 +1,13 @@
Copyright (c) 2015, Kegan Myers <kegan@keganmyers.com>
Permission to use, copy, modify, and/or distribute this software for any purpose
with or without fee is hereby granted, provided that the above copyright notice
and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
THIS SOFTWARE.

53
README.md Normal file
View file

@ -0,0 +1,53 @@
CFHA
====
CloudFlare High Availability monitor
CFHA is a simple daemon that will continually monitor servers you specify and
add/remove them from a shared "A" record in cloudflare.
Configuration
=============
Configuring CFHA is done through a JSON file, which should be named config.json,
and placed in whatever directory you will run CFHA from.
Example configuration file:
```js
{
"hosts": [ //an array of hosts to check
{
"host": "192.168.1.1", //the IP address of the host
"type": "http", //the type of check to run, can be either http or https
"options": {} //optional additional parameters to the check module
},
{
"host": "192.168.1.2",
"type": "https",
"options": {
"hostname": "lb-check-hostname" //this is the only currently supported parameter, and will be sent as the "host" header of an http(s) request
}
}
],
"cloudflare": { //cloudflare configuration
"email": "cfemail@example.com",
"apiKey": "CF_API_KEY", //get this from your cloudflare profile
"domain": "example.com", //the domain in cloudflare you will be operating on
"name": "lb.example.com", //the full dns record you wish to edit
"ttl": "1" //1 is automatic, otherwise see the cloudflare documentation on TTL
},
"interval": 1 //how often (in seconds) to ping the server, note that this is a number, not a string
}
```
Limitations
===========
CFHA is limited in a few ways, due both to the author, and due to limitations in cloudflare's API / how DNS works.
1. CFHA can only operate on `A` records since it is invalid to have multiple values for CNAME records.
2. You must specify each host by IP address because CFHA does not resolve names to IP addresses yet. (And we need to have IP addresses for A records). An interesting feature of implementing this is that you could create a pool A record and CFHA would monitor all of those via a single host entry pointing to that record, but it would require a lot more logic.
3. CFHA does not operate on IPv6. This is something that is possible (and maybe even simple) to implement, but has not yet been worked on.
4. CFHA is meant to operate on load balancers, and as such only checks for a 200 exit status on a host. You should add a name-based virtual host to nginx that returns 200 on each monitored server, and set the hostname in the check options.
License
=======
CFHA is made available under an ISC license. Anyone is welcome to make contributions with the understanding that they will be released under that same license.

362
cloudflare/LICENSE Normal file
View file

@ -0,0 +1,362 @@
Mozilla Public License, version 2.0
1. Definitions
1.1. "Contributor"
means each individual or legal entity that creates, contributes to the
creation of, or owns Covered Software.
1.2. "Contributor Version"
means the combination of the Contributions of others (if any) used by a
Contributor and that particular Contributor's Contribution.
1.3. "Contribution"
means Covered Software of a particular Contributor.
1.4. "Covered Software"
means Source Code Form to which the initial Contributor has attached the
notice in Exhibit A, the Executable Form of such Source Code Form, and
Modifications of such Source Code Form, in each case including portions
thereof.
1.5. "Incompatible With Secondary Licenses"
means
a. that the initial Contributor has attached the notice described in
Exhibit B to the Covered Software; or
b. that the Covered Software was made available under the terms of
version 1.1 or earlier of the License, but not also under the terms of
a Secondary License.
1.6. "Executable Form"
means any form of the work other than Source Code Form.
1.7. "Larger Work"
means a work that combines Covered Software with other material, in a
separate file or files, that is not Covered Software.
1.8. "License"
means this document.
1.9. "Licensable"
means having the right to grant, to the maximum extent possible, whether
at the time of the initial grant or subsequently, any and all of the
rights conveyed by this License.
1.10. "Modifications"
means any of the following:
a. any file in Source Code Form that results from an addition to,
deletion from, or modification of the contents of Covered Software; or
b. any new file in Source Code Form that contains any Covered Software.
1.11. "Patent Claims" of a Contributor
means any patent claim(s), including without limitation, method,
process, and apparatus claims, in any patent Licensable by such
Contributor that would be infringed, but for the grant of the License,
by the making, using, selling, offering for sale, having made, import,
or transfer of either its Contributions or its Contributor Version.
1.12. "Secondary License"
means either the GNU General Public License, Version 2.0, the GNU Lesser
General Public License, Version 2.1, the GNU Affero General Public
License, Version 3.0, or any later versions of those licenses.
1.13. "Source Code Form"
means the form of the work preferred for making modifications.
1.14. "You" (or "Your")
means an individual or a legal entity exercising rights under this
License. For legal entities, "You" includes any entity that controls, is
controlled by, or is under common control with You. For purposes of this
definition, "control" means (a) the power, direct or indirect, to cause
the direction or management of such entity, whether by contract or
otherwise, or (b) ownership of more than fifty percent (50%) of the
outstanding shares or beneficial ownership of such entity.
2. License Grants and Conditions
2.1. Grants
Each Contributor hereby grants You a world-wide, royalty-free,
non-exclusive license:
a. under intellectual property rights (other than patent or trademark)
Licensable by such Contributor to use, reproduce, make available,
modify, display, perform, distribute, and otherwise exploit its
Contributions, either on an unmodified basis, with Modifications, or
as part of a Larger Work; and
b. under Patent Claims of such Contributor to make, use, sell, offer for
sale, have made, import, and otherwise transfer either its
Contributions or its Contributor Version.
2.2. Effective Date
The licenses granted in Section 2.1 with respect to any Contribution
become effective for each Contribution on the date the Contributor first
distributes such Contribution.
2.3. Limitations on Grant Scope
The licenses granted in this Section 2 are the only rights granted under
this License. No additional rights or licenses will be implied from the
distribution or licensing of Covered Software under this License.
Notwithstanding Section 2.1(b) above, no patent license is granted by a
Contributor:
a. for any code that a Contributor has removed from Covered Software; or
b. for infringements caused by: (i) Your and any other third party's
modifications of Covered Software, or (ii) the combination of its
Contributions with other software (except as part of its Contributor
Version); or
c. under Patent Claims infringed by Covered Software in the absence of
its Contributions.
This License does not grant any rights in the trademarks, service marks,
or logos of any Contributor (except as may be necessary to comply with
the notice requirements in Section 3.4).
2.4. Subsequent Licenses
No Contributor makes additional grants as a result of Your choice to
distribute the Covered Software under a subsequent version of this
License (see Section 10.2) or under the terms of a Secondary License (if
permitted under the terms of Section 3.3).
2.5. Representation
Each Contributor represents that the Contributor believes its
Contributions are its original creation(s) or it has sufficient rights to
grant the rights to its Contributions conveyed by this License.
2.6. Fair Use
This License is not intended to limit any rights You have under
applicable copyright doctrines of fair use, fair dealing, or other
equivalents.
2.7. Conditions
Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
Section 2.1.
3. Responsibilities
3.1. Distribution of Source Form
All distribution of Covered Software in Source Code Form, including any
Modifications that You create or to which You contribute, must be under
the terms of this License. You must inform recipients that the Source
Code Form of the Covered Software is governed by the terms of this
License, and how they can obtain a copy of this License. You may not
attempt to alter or restrict the recipients' rights in the Source Code
Form.
3.2. Distribution of Executable Form
If You distribute Covered Software in Executable Form then:
a. such Covered Software must also be made available in Source Code Form,
as described in Section 3.1, and You must inform recipients of the
Executable Form how they can obtain a copy of such Source Code Form by
reasonable means in a timely manner, at a charge no more than the cost
of distribution to the recipient; and
b. You may distribute such Executable Form under the terms of this
License, or sublicense it under different terms, provided that the
license for the Executable Form does not attempt to limit or alter the
recipients' rights in the Source Code Form under this License.
3.3. Distribution of a Larger Work
You may create and distribute a Larger Work under terms of Your choice,
provided that You also comply with the requirements of this License for
the Covered Software. If the Larger Work is a combination of Covered
Software with a work governed by one or more Secondary Licenses, and the
Covered Software is not Incompatible With Secondary Licenses, this
License permits You to additionally distribute such Covered Software
under the terms of such Secondary License(s), so that the recipient of
the Larger Work may, at their option, further distribute the Covered
Software under the terms of either this License or such Secondary
License(s).
3.4. Notices
You may not remove or alter the substance of any license notices
(including copyright notices, patent notices, disclaimers of warranty, or
limitations of liability) contained within the Source Code Form of the
Covered Software, except that You may alter any license notices to the
extent required to remedy known factual inaccuracies.
3.5. Application of Additional Terms
You may choose to offer, and to charge a fee for, warranty, support,
indemnity or liability obligations to one or more recipients of Covered
Software. However, You may do so only on Your own behalf, and not on
behalf of any Contributor. You must make it absolutely clear that any
such warranty, support, indemnity, or liability obligation is offered by
You alone, and You hereby agree to indemnify every Contributor for any
liability incurred by such Contributor as a result of warranty, support,
indemnity or liability terms You offer. You may include additional
disclaimers of warranty and limitations of liability specific to any
jurisdiction.
4. Inability to Comply Due to Statute or Regulation
If it is impossible for You to comply with any of the terms of this License
with respect to some or all of the Covered Software due to statute,
judicial order, or regulation then You must: (a) comply with the terms of
this License to the maximum extent possible; and (b) describe the
limitations and the code they affect. Such description must be placed in a
text file included with all distributions of the Covered Software under
this License. Except to the extent prohibited by statute or regulation,
such description must be sufficiently detailed for a recipient of ordinary
skill to be able to understand it.
5. Termination
5.1. The rights granted under this License will terminate automatically if You
fail to comply with any of its terms. However, if You become compliant,
then the rights granted under this License from a particular Contributor
are reinstated (a) provisionally, unless and until such Contributor
explicitly and finally terminates Your grants, and (b) on an ongoing
basis, if such Contributor fails to notify You of the non-compliance by
some reasonable means prior to 60 days after You have come back into
compliance. Moreover, Your grants from a particular Contributor are
reinstated on an ongoing basis if such Contributor notifies You of the
non-compliance by some reasonable means, this is the first time You have
received notice of non-compliance with this License from such
Contributor, and You become compliant prior to 30 days after Your receipt
of the notice.
5.2. If You initiate litigation against any entity by asserting a patent
infringement claim (excluding declaratory judgment actions,
counter-claims, and cross-claims) alleging that a Contributor Version
directly or indirectly infringes any patent, then the rights granted to
You by any and all Contributors for the Covered Software under Section
2.1 of this License shall terminate.
5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
license agreements (excluding distributors and resellers) which have been
validly granted by You or Your distributors under this License prior to
termination shall survive termination.
6. Disclaimer of Warranty
Covered Software is provided under this License on an "as is" basis,
without warranty of any kind, either expressed, implied, or statutory,
including, without limitation, warranties that the Covered Software is free
of defects, merchantable, fit for a particular purpose or non-infringing.
The entire risk as to the quality and performance of the Covered Software
is with You. Should any Covered Software prove defective in any respect,
You (not any Contributor) assume the cost of any necessary servicing,
repair, or correction. This disclaimer of warranty constitutes an essential
part of this License. No use of any Covered Software is authorized under
this License except under this disclaimer.
7. Limitation of Liability
Under no circumstances and under no legal theory, whether tort (including
negligence), contract, or otherwise, shall any Contributor, or anyone who
distributes Covered Software as permitted above, be liable to You for any
direct, indirect, special, incidental, or consequential damages of any
character including, without limitation, damages for lost profits, loss of
goodwill, work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses, even if such party shall have been
informed of the possibility of such damages. This limitation of liability
shall not apply to liability for death or personal injury resulting from
such party's negligence to the extent applicable law prohibits such
limitation. Some jurisdictions do not allow the exclusion or limitation of
incidental or consequential damages, so this exclusion and limitation may
not apply to You.
8. Litigation
Any litigation relating to this License may be brought only in the courts
of a jurisdiction where the defendant maintains its principal place of
business and such litigation shall be governed by laws of that
jurisdiction, without reference to its conflict-of-law provisions. Nothing
in this Section shall prevent a party's ability to bring cross-claims or
counter-claims.
9. Miscellaneous
This License represents the complete agreement concerning the subject
matter hereof. If any provision of this License is held to be
unenforceable, such provision shall be reformed only to the extent
necessary to make it enforceable. Any law or regulation which provides that
the language of a contract shall be construed against the drafter shall not
be used to construe this License against a Contributor.
10. Versions of the License
10.1. New Versions
Mozilla Foundation is the license steward. Except as provided in Section
10.3, no one other than the license steward has the right to modify or
publish new versions of this License. Each version will be given a
distinguishing version number.
10.2. Effect of New Versions
You may distribute the Covered Software under the terms of the version
of the License under which You originally received the Covered Software,
or under the terms of any subsequent version published by the license
steward.
10.3. Modified Versions
If you create software not governed by this License, and you want to
create a new license for such software, you may create and use a
modified version of this License if you rename the license and remove
any references to the name of the license steward (except to note that
such modified license differs from this License).
10.4. Distributing Source Code Form that is Incompatible With Secondary
Licenses If You choose to distribute Source Code Form that is
Incompatible With Secondary Licenses under the terms of this version of
the License, the notice described in Exhibit B of this License must be
attached.
Exhibit A - Source Code Form License Notice
This Source Code Form is subject to the
terms of the Mozilla Public License, v.
2.0. If a copy of the MPL was not
distributed with this file, You can
obtain one at
http://mozilla.org/MPL/2.0/.
If it is not possible or desirable to put the notice in a particular file,
then You may include the notice in a location (such as a LICENSE file in a
relevant directory) where a recipient would be likely to look for such a
notice.
You may add additional accurate notices of copyright ownership.
Exhibit B - "Incompatible With Secondary Licenses" Notice
This Source Code Form is "Incompatible
With Secondary Licenses", as defined by
the Mozilla Public License, v. 2.0.

19
cloudflare/README.md Normal file
View file

@ -0,0 +1,19 @@
# Note
This is a modification of the original `github.com/pearkes/cloudflare` package, and has changes
that align with the goals of the `cfha` project. Don't
## cloudflare
This package provides the `cloudflare` package which offers
an interface to the CloudFlare gAPI.
It's intentionally designed to make heavy use of built-ins and strings
in place of custom data structures and proper types. It also only implements
specific endpoints, and doesn't have full API coverage.
**For those reasons, I recommend looking elsewhere if you just need
a standard CloudFlare API client.**
### Documentation
The full documentation is available on [Godoc](http://godoc.org/github.com/pearkes/cloudflare)

109
cloudflare/api.go Normal file
View file

@ -0,0 +1,109 @@
package cloudflare
import (
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"net/url"
)
// Client provides a client to the CloudflAre API
type Client struct {
// Access Token
Token string
// User Email
Email string
// URL to the DO API to use
URL string
// HttpClient is the client to use. Default will be
// used if not provided.
Http *http.Client
}
// NewClient returns a new cloudflare client,
// requires an authorization token. You can generate
// an OAuth token by visiting the Apps & API section
// of the CloudflAre control panel for your account.
//-Can't return an error
func NewClient(email string, token string) (*Client) {
//-Removed environment grabbing
client := Client{
Token: token,
Email: email,
URL: "https://www.cloudflare.com/api_json.html",
Http: http.DefaultClient,
}
return &client
}
// Creates a new request with the params
func (c *Client) NewRequest(params map[string]string, method string, action string) (*http.Request, error) {
p := url.Values{}
u, err := url.Parse(c.URL)
if err != nil {
return nil, err
}
// Build up our request parameters
for k, v := range params {
p.Add(k, v)
}
// Add authentication details
p.Add("tkn", c.Token)
p.Add("email", c.Email)
// The "action" to take against the API
p.Add("a", action)
// Add the params to our URL
u.RawQuery = p.Encode()
// Build the request
req, err := http.NewRequest(method, u.String(), nil)
if err != nil {
return nil, err
}
return req, nil
}
// decodeBody is used to JSON decode a body
func decodeBody(resp *http.Response, out interface{}) error {
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return err
}
if err = json.Unmarshal(body, &out); err != nil {
return err
}
return nil
}
// checkResp wraps http.Client.Do() and verifies that the
// request was successful. A non-200 request returns an error
// formatted to included any validation problems or otherwise
func checkResp(resp *http.Response, err error) (*http.Response, error) {
// If the err is already there, there was an error higher
// up the chain, so just return that
if err != nil {
return resp, err
}
switch i := resp.StatusCode; {
case i == 200:
return resp, nil
default:
return nil, fmt.Errorf("API Error: %s", resp.Status)
}
}

189
cloudflare/record.go Normal file
View file

@ -0,0 +1,189 @@
package cloudflare
import (
"fmt"
)
//~Return the actual error when possible
type RecordsResponse struct {
Response struct {
Recs struct {
Records []Record `json:"objs"`
} `json:"recs"`
} `json:"response"`
Result string `json:"result"`
Message string `json:"msg"`
}
//-Removed wildcard option
func (r *RecordsResponse) FindRecordByName(name string) ([]Record, error) {
if r.Result == "error" {
return nil, fmt.Errorf("API Error: %s", r.Message)
}
objs := r.Response.Recs.Records
var recs []Record
//-Removed errror on no results
//-Removed wildcard checking
//~Checking against FullName, not just name
for _, v := range objs {
if v.FullName == name {
recs = append(recs, v)
}
}
return recs, nil
}
type RecordResponse struct {
Response struct {
Rec struct {
Record Record `json:"obj"`
} `json:"rec"`
} `json:"response"`
Result string `json:"result"`
Message string `json:"msg"`
}
func (r *RecordResponse) GetRecord() (*Record, error) {
if r.Result == "error" {
return nil, fmt.Errorf("API Error: %s", r.Message)
}
return &r.Response.Rec.Record, nil
}
// Record is used to represent a retrieved Record. All properties
// are set as strings.
type Record struct {
Id string `json:"rec_id"`
Domain string `json:"zone_name"`
Name string `json:"display_name"`
FullName string `json:"name"`
Value string `json:"content"`
Type string `json:"type"`
Priority string `json:"prio"`
Ttl string `json:"ttl"`
}
// CreateRecord contains the request parameters to create a new
// record.
type CreateRecord struct {
Type string
Name string
Content string
Ttl string
Priority string
}
// CreateRecord creates a record from the parameters specified and
// returns an error if it fails. If no error and the name is returned,
// the Record was succesfully created.
func (c *Client) CreateRecord(domain string, opts *CreateRecord) (*Record, error) {
// Make the request parameters
params := make(map[string]string)
//-No option checking, we set them all ourselves
params["z"] = domain
params["type"] = opts.Type
params["name"] = opts.Name
params["content"] = opts.Content
params["prio"] = opts.Priority
params["ttl"] = "1"
req, err := c.NewRequest(params, "POST", "rec_new")
if err != nil {
return nil, err
}
resp, err := checkResp(c.Http.Do(req))
if err != nil {
return nil, err
}
recordResp := new(RecordResponse)
err = decodeBody(resp, &recordResp)
if err != nil {
return nil, err
}
record, err := recordResp.GetRecord()
if err != nil {
return nil, err
}
// The request was successful
return record, nil
}
// DestroyRecord destroys a record by the ID specified and
// returns an error if it fails. If no error is returned,
// the Record was succesfully destroyed.
func (c *Client) DestroyRecord(domain string, id string) error {
params := make(map[string]string)
params["z"] = domain
params["id"] = id
req, err := c.NewRequest(params, "POST", "rec_delete")
if err != nil {
return err
}
resp, err := checkResp(c.Http.Do(req))
if err != nil {
return err
}
recordResp := new(RecordResponse)
err = decodeBody(resp, &recordResp)
if err != nil {
return err
}
_, err = recordResp.GetRecord()
if err != nil {
return err
}
// The request was successful
return nil
}
func (c *Client) RetrieveRecordsByName(domain string, name string) ([]Record, error) {
params := make(map[string]string)
params["z"] = domain
req, err := c.NewRequest(params, "GET", "rec_load_all")
if err != nil {
return nil, err
}
resp, err := checkResp(c.Http.Do(req))
if err != nil {
return nil, err
}
records := new(RecordsResponse)
err = decodeBody(resp, records)
if err != nil {
return nil, err
}
record, err := records.FindRecordByName(name)
if err != nil {
return nil, err
}
// The request was successful
return record, nil
}

31
main.go Normal file
View file

@ -0,0 +1,31 @@
package main
import (
"log"
"fmt"
"io/ioutil"
"encoding/json"
"./monitor"
)
func main() {
file, err := ioutil.ReadFile("./config.json")
if err != nil {
log.Fatal(fmt.Sprintf("%v\n", err))
}
c := monitor.Config{}
json.Unmarshal(file, &c)
handlers := make([]monitor.GenericHandler, 2)
handlers[0] = monitor.NewLogHandler()
handlers[1] = monitor.NewCloudflareHandler(c.Cloudflare)
engine := monitor.CreateEngine(handlers)
for _, endpoint := range c.Hosts {
monitor.CreateCheck(c.Interval, engine, endpoint)
}
select{}
}

75
monitor/cloudflare.go Normal file
View file

@ -0,0 +1,75 @@
package monitor
import (
"../cloudflare"
"log"
"fmt"
)
func NewCloudflareHandler(config CloudflareConfig) GenericHandler {
return runHandler(make(chan Transition, 5), &cloudflareHandler{
config,
cloudflare.NewClient(config.Email, config.ApiKey),
make(map[string]bool),
})
}
type cloudflareHandler struct{
config CloudflareConfig
client *cloudflare.Client
actuallyDownHosts map[string]bool
}
func (this *cloudflareHandler) handle(transition Transition) {
switch transition.To {
case Down:
log.Print(fmt.Sprintf(
"Removed cloudflare record for `%s`: `%v`\n",
transition.RecordValue,
removeCloudflareRecord(this.client, this.config, transition.RecordValue)))
case Up:
log.Print(fmt.Sprintf(
"Added cloudflare record for `%s`: `%v`\n",
transition.RecordValue,
addCloudflareRecord(this.client, this.config, transition.RecordValue)))
case Unknown: //just leave it how it was, going up/down is idempotent anyways
}
}
func removeCloudflareRecord(client *cloudflare.Client, config CloudflareConfig, recordValue string) bool {
records, err := client.RetrieveRecordsByName(config.Domain, config.Name)
if err != nil {
return false
}
exitStatus := true
for _, record := range records {
if record.Value != recordValue {
continue
}
exitStatus = exitStatus && client.DestroyRecord(config.Domain, record.Id) == nil
}
return exitStatus
}
func addCloudflareRecord(client *cloudflare.Client, config CloudflareConfig, recordValue string) bool {
opts := cloudflare.CreateRecord{
"A",
config.Name,
recordValue,
"1",
"0",
}
_, err := client.CreateRecord(config.Domain, &opts)
if err != nil {
return fmt.Sprintf("%s", err) == "API Error: The record already exists."
}
return true
}

21
monitor/config.go Normal file
View file

@ -0,0 +1,21 @@
package monitor
type HostConfig struct {
Host string
Type string
Options map[string]string
}
type CloudflareConfig struct {
Email string
ApiKey string
Domain string
Name string
Ttl string
}
type Config struct {
Cloudflare CloudflareConfig
Hosts []HostConfig
Interval uint16
}

70
monitor/createCheck.go Normal file
View file

@ -0,0 +1,70 @@
package monitor
import (
"net/http"
"time"
"log"
"fmt"
)
type checkConfig struct {
engine *Engine
interval time.Duration
host HostConfig
}
type httpChecker struct {
client *http.Client
config checkConfig
endpoint string
}
func (this *httpChecker) run() {
log.Print(fmt.Sprintf("Starting: %v\n", this.config.host))
for true {
this.config.engine.Input<- Result{
this.config.host.Host,
this.check(),
}
time.Sleep(this.config.interval)
}
}
func (this *httpChecker) check() Status {
req, err := http.NewRequest("GET", this.endpoint, nil)
if err != nil {
log.Print(fmt.Sprintf("Stopping: %v due to http NewRequest error\n", this.config.host))
return Unknown
}
req.Header.Set("Host", this.config.host.Options["hostname"])
return this.determineHttpCheckStatus(this.client.Do(req))
}
func (this *httpChecker) determineHttpCheckStatus(res *http.Response, err error) Status {
if err != nil || res.StatusCode != 200 {
return Down
}
return Up
}
func newHttpChecker(config checkConfig) *httpChecker {
checker := httpChecker{
&http.Client{},
config,
config.host.Type + "://" + config.host.Host + "/",
}
go checker.run()
return &checker
}
func CreateCheck(interval uint16, engine *Engine, host HostConfig) {
config := checkConfig{
engine,
time.Duration(int64(interval)) * time.Second,
host,
}
switch host.Type {
case "http", "https":
newHttpChecker(config)
}
}

51
monitor/engine.go Normal file
View file

@ -0,0 +1,51 @@
package monitor
import (
)
type Engine struct {
Input chan Result
output []GenericHandler
}
func CreateEngine(handlers []GenericHandler) *Engine {
input := make(chan Result)
engine := Engine{
input,
handlers,
}
e := &engine
go e.startProcessor()
return e
}
func (this *Engine) startProcessor() {
statuses := make(map[string]Status)
for true {
result := <-this.Input
//No transition if we don't exist
if result.Status == statuses[result.RecordValue] {
continue
}
//Create a record with to, from
change := Transition{
result.Status,
statuses[result.RecordValue],
result.RecordValue,
}
//Send the record to everyone who cares
for _, relay := range this.output {
relay.channel<- change
}
//And set our new status
statuses[result.RecordValue] = result.Status
}
}

20
monitor/handler.go Normal file
View file

@ -0,0 +1,20 @@
package monitor
type handler interface{
handle(transition Transition)
}
type GenericHandler struct {
channel chan Transition
}
func runHandler(input chan Transition, handler handler) GenericHandler {
go func() {
for true {
handler.handle(<-input)
}
}()
return GenericHandler{
input,
}
}

19
monitor/log.go Normal file
View file

@ -0,0 +1,19 @@
package monitor
import (
"fmt"
"log"
)
func NewLogHandler() GenericHandler {
return runHandler(make(chan Transition), &logHandler{})
}
type logHandler struct{}
func (this *logHandler) handle(transition Transition) {
log.Print(fmt.Sprintf(
"`%s` has become `%d` - `%s`",
transition.RecordValue, transition.To,
transition.To.String()))
}

6
monitor/result.go Normal file
View file

@ -0,0 +1,6 @@
package monitor
type Result struct {
RecordValue string
Status Status
}

27
monitor/transition.go Normal file
View file

@ -0,0 +1,27 @@
package monitor
type Status int
const (
Unknown Status = iota
Up Status = iota
Down Status = iota
)
func (t Status) String() string {
if t == Unknown {
return "Unknown"
} else if t == Up {
return "Up"
} else if t == Down {
return "Down"
}
return ""
}
type Transition struct {
To Status
From Status
RecordValue string
}