Commit Graph

835 Commits

Author SHA1 Message Date
Harshavardhana 28352f3f5d log: Startup banner should strip standard ports. (#4443)
APIEndpoints list should strip off standard ports
to avoid confusion with clients.
2017-05-31 09:21:28 -07:00
Harshavardhana 975972d57e server: Redirection should use globalMinioPort with host without port. (#4445)
Currently redirection doesn't work in following scenarios

 - server started with port ":80" and TLS is configured
   client requested insecure request on port "80"
   gets redirected to port 443 and fails.
2017-05-31 09:21:02 -07:00
Harshavardhana 458f22f37c log: Fix printing of signature error request headers. (#4444)
The following commit f44f2e341c
fix was incomplete and we still had presigned URLs printing
in query strings in wrong fashion.

This PR fixes this properly. Avoid double encoding
percent encoded strings such as

`s3%!!(MISSING)A(MISSING)`

Print properly as json encoded.

`s3%3AObjectCreated%3A%2A`
2017-05-31 00:11:06 -07:00
Krishna Srinivas 0bba3cc8e3 gateway-azure: Convert S3 metadata to azure metadata (#4384)
fixes #4292
2017-05-30 20:05:41 -07:00
Harshavardhana 072fcf3ba6 fs: Make sure to validate bucket first in PutObject() (#4427)
Currently even when bucket doesn't exist we wrongly
return success, when an object is a directory prefix with
 '/' as suffix and is of size 0.

This PR fixes this behavior.
2017-05-25 09:22:43 -07:00
Harshavardhana b78f6fbcc5 Do not send envVars in ServerInfo() (#4422)
Sending envVars along with access and secret
exposes the entire minio server's sensitive
information. This will be an unexpected
situation for all users.

If at all we need to look for things like if
credentials are set through env, we should
only have access to only this information
not the entire set of system envs.
2017-05-24 21:09:23 -07:00
samkevich 99ca8a2928 fix InvalidAccessKeyId error according to amazon documentation (#4404)
http://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html
2017-05-23 20:07:52 -07:00
poornas 9b3dd44607 Add dotnet library to minio startup message (#4410) 2017-05-23 13:57:27 -07:00
Krishnan Parthasarathi 3c5db69ffd Treat 0.0.0.0 as local address in --address flag (#4386) 2017-05-23 12:07:39 -07:00
Krishna Srinivas 28c26a9e59 Generate random ETag if client does not provide MD5 for PutObjectPart (#4385)
fixes #4289
fixes #4290
2017-05-22 15:48:48 -07:00
luomeiqin 9d98bf1c0f Bucket names can contain hyphen (#4324) 2017-05-19 07:30:00 -07:00
Harshavardhana 1886d94e95 server/mux: Use constants provided by Go http (#4360) 2017-05-17 11:57:52 -07:00
Anis Elleuch 542f7ae42c gateway: Reject endpoint pointing to local gateway (#4310)
Show an error when the user enters an endpoint url pointing
to the gateway server itself.
2017-05-16 21:13:29 -07:00
Harshavardhana 59b3e0b79b auth/rpc: Add RWMutex instead of Mutex for granular locking. (#4352)
Refer https://github.com/minio/minio/issues/4345
2017-05-16 14:34:56 -07:00
Aditya Manthramurthy 8975da4e84 Add new ReadFileWithVerify storage-layer API (#4349)
This is an enhancement to the XL/distributed-XL mode. FS mode is
unaffected.

The ReadFileWithVerify storage-layer call is similar to ReadFile with
the additional functionality of performing bit-rot checking. It
accepts additional parameters for a hashing algorithm to use and the
expected hex-encoded hash string.

This patch provides significant performance improvement because:

1. combines the step of reading the file (during
erasure-decoding/reconstruction) with bit-rot verification;

2. limits the number of file-reads; and

3. avoids transferring the file over the network for bit-rot
verification.

ReadFile API is implemented as ReadFileWithVerify with empty hashing
arguments.

Credits to AB and Harsha for the algorithmic improvement.

Fixes #4236.
2017-05-16 14:21:52 -07:00
Frank cae4683971 Make clearing of stale debug lock info independent of deleting map entry of lock itself. (#4353)
This is believed to address issue #4337 where stale information for debug locks in shown.
2017-05-16 07:19:17 -07:00
Krishna Srinivas 5db1e9f3dd signature: use region from Auth header if server's region not configured (#4329) 2017-05-15 18:17:02 -07:00
Anis Elleuch 465274cd21 server-info: Change Error type to string (#4346)
Golang std error type doesn't marshal/unmarshal with json. So errors
are not actually being sent when a client calls ServerInfo() API.
2017-05-15 07:28:47 -07:00
Harshavardhana 87fb911d38 Rename structs for azure and s3 gateway to be consistent. (#4347) 2017-05-15 00:52:33 -07:00
Harshavardhana 155a90403a fs/erasure: Rename meta 'md5Sum' as 'etag'. (#4319)
This PR also does backend format change to 1.0.1
from 1.0.0.  Backward compatible changes are still
kept to read the 'md5Sum' key. But all new objects
will be stored with the same details under 'etag'.

Fixes #4312
2017-05-14 12:05:51 -07:00
Harshavardhana c63afabc9b build/release: Generate sha256sums also without the release tag. (#4318)
Ref #4306
2017-05-12 21:40:22 -07:00
Anis Elleuch f2ed149714 Add slack channel link to corrupted disk err msg (#4270) 2017-05-11 14:27:32 -07:00
Harshavardhana 5a16dcf4cf Add a graceful msg when CTRL+C is pressed. (#4248) 2017-05-11 14:27:18 -07:00
Krishna Srinivas bb292e4e38 web-handler: Allow anonymous download of zip (#4309)
fixes #4230
2017-05-10 09:54:24 -07:00
Harshavardhana fa3f6d75b6 fs: Verify if parent is an object before i/o. (#4304)
PutObject() needs to verify and fail.

Fixes #4301
2017-05-09 17:46:46 -07:00
Harshavardhana 298b470f69 fs/erasure: Ignore objects with / even for DeleteObject() (#4303)
Additionally GetObject() also returns errFileNotFound similar
to HeadObject().

Fixes #4302
2017-05-09 14:32:24 -07:00
Krishna Srinivas fc774957fe gateway: reject requests with unknown authorization (#4297) 2017-05-09 07:53:31 -07:00
Anis Elleuch 85bc6003e9 gateway-s3: Avoid x2 double quotes in ListParts (#4295)
ListParts response returns doubled double quotes in ETag field.
This commit cleans ETag when receiving it from minio client to
fix the issue.
2017-05-08 14:42:05 -07:00
Harshavardhana 610dbe3479 config: Do not migrate config file if not needed. (#4264)
Also improve the error message returned by `pkg/quick`.

Fixes #4233
2017-05-06 10:16:59 -07:00
Harshavardhana 76f4f20609 fs: Migrate object metadata to objects directory. (#4195)
Fixes #3352
2017-05-05 08:49:09 -07:00
Harshavardhana 99ddd35343 docs: use IEC format such as iB everywhere. (#4247) 2017-05-05 08:28:08 -07:00
Remco Verhoef 01e9adc4b3 Implement anonymous uploads, fixes #4250 (#4259) 2017-05-04 20:03:56 -07:00
Harshavardhana df027a8f51 Webhook endpoints can fail, we must start the server. (#4255)
This PR fixes a regression introduced in #4060
2017-05-04 13:43:54 -07:00
Krishnan Parthasarathi 02910725c5 Make gateway help for s3/azure similar (#4249) 2017-05-04 10:38:48 -07:00
Remco Verhoef 069cf9e8aa Use s3.amazonaws.com as default endpoint, fixes #4240 (#4242) 2017-05-03 22:41:03 -07:00
Aditya Manthramurthy 2121b78ea7 Fix bug in JSON representation of object properties (#4238)
Introduced in #4003
2017-05-03 20:10:00 -07:00
Remco Verhoef 5016649f47 Add s3 backend to help, fixes #4219 (#4221)
* Add s3 backend to help, fixes #4219

* Add samples for Gateway usage with S3
2017-05-03 17:55:30 -07:00
Bala FA 2b78444056 fix: ignore TLS handshake error. (#4227)
Fixes #4200
2017-05-03 03:23:15 -07:00
Karthic Rao 9b58a669e5 tests: Fix rare test crash (#4175)
Fix rare test crash by improving the randomness logic.
2017-05-02 23:54:22 -07:00
Krishna Srinivas e5b2e25caf gateway-s3: vendor-update minio-go (#4220) 2017-05-02 18:46:39 -07:00
Krishna Srinivas 4aa65910e5 gateway: Restore bucket policy functionality for Azure (#4209) 2017-05-02 12:27:25 -07:00
Harshavardhana 8b272a3163 config: Improve config migrate messaging. (#4216)
Previous message

```
Migration from version ‘17’ to ‘18’ completed successfully.
```

For example didn't provide any meaningful insights.

This PR attempts to improve this message as below

```
Configuration file '/home/harsha/.minio/config.json' migrated from version '17' to '18' successfully.
```

Fixes #4199
2017-05-02 11:43:27 -07:00
Harshavardhana f0b5c0ec7c windows: Support all REPARSE_POINT attrib files properly. (#4203)
This change adopts the upstream fix in this regard at
https://go-review.googlesource.com/#/c/41834/ for Minio's
purposes.

Go's current os.Stat() lacks support for lot of strange
windows files such as

 - share symlinks on SMB2
 - symlinks on docker nanoserver
 - de-duplicated files on NTFS de-duplicated volume.

This PR attempts to incorporate the change mentioned here

   https://blogs.msdn.microsoft.com/oldnewthing/20100212-00/?p=14963/

The article suggests to use Windows I/O manager to
dereference the symbolic link.

Fixes #4122
2017-05-02 02:35:27 -07:00
Remco Verhoef 44d53c9c67 cleanup and fix comments (#4212) 2017-05-01 14:44:31 -07:00
Krishna Srinivas 6cf6828a4c gateway: Rename gateway files to have "gateway-" prefix (#4207) 2017-05-01 10:32:18 -07:00
Krishna Srinivas 01f04c717e gateway: reject bad path segments in URL (#4202) 2017-04-28 17:17:18 -07:00
Krishna Srinivas 0d32b22359 gateway: Fix help message for gateway (#4201) 2017-04-28 16:42:16 -07:00
Anis Elleuch d36dd80a8a cors: Set Access-Control-Allow-Credentials to true (#4185)
This allow browsers to send credentials with preflighted requests.
2017-04-27 12:40:22 -07:00
Remco Verhoef 3a539ce660 Implement gateway S3 support (#3940) 2017-04-27 11:26:00 -07:00
Harshavardhana 57c5c75611 web: Simplify and converge common functions in web/obj API. (#4179)
RemoveObject() in webAPI currently re-implements some part
of the code to remove objects combine them for simplicity
and code convergence.
2017-04-26 23:27:48 -07:00
Bala FA cf1fc45142 Improve duration humanization. (#4071) 2017-04-26 03:38:35 -07:00
Harshavardhana 48aa2ac392 server: Validate path for bad components in a handler. (#4170) 2017-04-24 18:13:46 -07:00
Frank 0d1e2ab509 Remove hardcoded min and max limit for erasure coding (#4157) 2017-04-24 10:00:33 -07:00
Anis Elleuch 83abad0b37 admin: ServerInfo() returns info for each node (#4150)
ServerInfo() will gather information from all nodes before returning
it back to the client.
2017-04-21 07:15:53 -07:00
Harshavardhana df346753e1 api: Fix registering of s3 endpoint peers properly (#4159)
We need to have local peer initialized properly
for listen bucket to work, current code did initialize
properly but the resulting code was initializing
peer on a wrong target v/s what listen bucket expected
it to be.

This regression came in de204a0a52

Fixes #4158
2017-04-20 15:28:29 -07:00
Harshavardhana 5a3c5aec31 server/mux: Fix serverMux to set deadlines based on UTC time. (#4146)
Avoid using `time.Now()` instead rely on UTC time
for the final deadline, this is to be consistent with
all our internal functions.

Reduce the default read timeout to 15 seconds
in lieu with a newly discovered issue
   - https://github.com/minio/minio/issues/4139

Additionally also change the Read() conn wrapper
to set deadline only upon successful Reads().
2017-04-19 13:16:06 -07:00
Aditya Manthramurthy a4305742e8 Add key for Kafka messages (fixes #4143) (#4151) 2017-04-19 11:26:35 -07:00
Harshavardhana 640ebb2f79 lock: Fix missing formatting directives while printing. (#4147)
Current log prints in this form

```
ERRO[8150] Lock maintenance failed to remove entry for write
lock (should never happen)%!!(MISSING)(EXTRA ....
```

Fix this by using proper formatting directive.
2017-04-19 10:37:56 -07:00
Harshavardhana f4dac979a2 server: Fix message when corrupted or unsupported format is found. (#4142)
Refer https://github.com/minio/minio/issues/4140

This is a fix to provide a little more elaborate message.
2017-04-18 10:35:17 -07:00
Krishnan Parthasarathi 3032f0f505 Remove duration field from lock instrumentation (#4111)
Duration for which a lock was held can be computed from the `Since`
field of `OpsLockState`. It is the difference between current time and
time at which the namespace lock was held. This change avoids
superfluous instrumentation.
2017-04-15 11:40:01 -07:00
Harshavardhana 7765081db7 cache: Increasing caching GC percent from 20 to 50. (#4041)
Previous value was set to avoid large cache value build
up but we can clearly see this can cause lots of GC
pauses which can lead to significant drop in performance.

Change this value to 50% and decrease the value to 25%
once the 75% cache size is used. To have a larger
window for GC pauses.

Another change is to only allow caching if a server has
more than 24GB of RAM instead of 8GB.
2017-04-15 02:16:49 -07:00
Anis Elleuch 14f0047295 fs: Remove fs meta lock when PutObject() fails (#4114)
Removing the fs meta lock file when PutObject() encounters any error
during its execution, such as upload getting permatuerly cancelled
by the client.
2017-04-14 12:06:24 -07:00
Krishna Srinivas e6b2253da9 gateway: Fix help message for custom Azure Blob Storage endpoint. (#4113) 2017-04-14 11:02:43 -07:00
Krishnan Parthasarathi ca64b86112 Return possible states a heal operation (#4045) 2017-04-14 10:28:35 -07:00
Karthic Rao 5f065e2a96 server: Fix CI build complaints (#4119)
- Ineffassign fixes.
- Spell check correction.
2017-04-14 08:00:04 -07:00
Harshavardhana a7afa469e2 xl: Add stat calls to keep track of ignored errors. (#4117)
Such that in a situation where all errors were
ignored we need to reduce the errors using
readQuorum to get a consistent error value.

Without this change errors generated will
never be consistent with for an expected scenario.

For example in a 6 disk setup 1 disk is missing
and 5 do not have the volume (testbucket)

Without this change Stat() would result in different
errors depending on which disk died. Can cause
confusion to S3 client application.

This change addresses need to track type of
errors we ignored and bring readQuorum to
choose the maximally occuring as the value
of truth.
2017-04-14 01:46:16 -07:00
Bala FA d103d5fb7c server: Error out if loopback addr is used for Distributed Erasure (#4105) 2017-04-12 20:27:24 -07:00
Harshavardhana 6683247080 tests: Fix the sopradic test failure in TestListObjectPartsDiskNotFound (#4107)
getBucketInfo() should keep track errors ignored,
such that in a situation where all errors were
ignored we need to reduce the errors using readQuorum
to get a consistent error value.

This is the problem we see with DiskNotFound test
disks are randomly removed.

Fixes #4095
2017-04-12 15:38:35 -07:00
Anis Elleuch e4bd882f11 handlers: Ignore malformatted datetime type header (#4097)
Ignore headers, such as If-Modified-Since, If-Unmodified-Since, etc.. when they
are received with a format other than HTTP date.
2017-04-12 12:34:57 -07:00
Harshavardhana 952c618441 server: Fix a regression in printing startup banner. (#4100)
Octect based sorting was lost in the previous commit

de204a0a52

This PR fixes a regression - fixes #4099
2017-04-12 09:22:35 -07:00
Krishna Srinivas c5249c35d3 gateway: Support for custom endpoint. (#4086) 2017-04-11 17:44:26 -07:00
Bala FA de204a0a52 Add extensive endpoints validation (#4019) 2017-04-11 15:44:27 -07:00
Harshavardhana 1b1b9e4801 lock/rpc: change rpcPath to be called serviceEndpoint. (#4088)
This is a cleanup to ensure proper naming.
2017-04-11 10:25:21 -07:00
Karthic Rao 929a13f33f Fix for writes from Apache Spark. (#4074)
- Due to usage of amazon SDK, spark expects md5sum of empty string to be
  returned when it does PUT on a directory.
- The fix returns md5sum of a empty string for the above mentioned case.
- This fixes the issue of Apache Spark not being able to write into Minio.
2017-04-10 19:51:23 -07:00
Krishna Srinivas a4209c10ea signature-v4: Use sha256("") for calculating canonical request (#4064) 2017-04-10 09:58:08 -07:00
Harshavardhana b927523223 server: Introduce a new env MINIO_REGION. (#4078)
This is implemented to be able to override region
through command line just like how access and
secret keys are provided.
2017-04-09 10:44:10 -07:00
Aditya Manthramurthy 604417baf4 Allow cluster to start when only n/2 servers are up (#4066)
Fixes #3234.

Relaxes the quorum requirement to start the object layer, and skips
quick-healing at start-up (as no write quorum is present).
2017-04-09 00:28:27 -07:00
Harshavardhana 0497d5c342 api: SourceInfo should be populated in GET/HEAD notification. (#4073)
Refer https://github.com/minio/mc/issues/2073
2017-04-08 01:39:20 -07:00
Harshavardhana 6b4f368dfe notify: Webhook endpoints can fail, but we must start the server. (#4060)
Ignore any network errors when registering a webhook
notifier during Minio startup sequence. This way server
can be started even if the webhook endpoint is not available
and unreachable.
2017-04-08 01:13:55 -07:00
Harshavardhana f44f2e341c log: Dump signature request properly. (#4063)
Currently percent encoded strings are not properly encoded.

`s3%!!(MISSING)A(MISSING)`

Print properly as json encoded.

`s3%3AObjectCreated%3A%2A`
2017-04-07 14:37:32 -07:00
Harshavardhana 27749c2124 admin/info: Add HTTPStats value as part of serverInfo() struct. (#4049)
Remove our counter implementation instead use atomic external
package which supports more types and methods.
2017-04-06 23:08:33 -07:00
Krishna Srinivas 1d99a560e3 refactor: extractSignedHeaders() handles headers removed by Go http server (#4054)
* refactor: extractSignedHeaders() handles headers removed by Go http server.
* Cleanup extractSignedHeaders() TestExtractSignedHeaders()
2017-04-05 17:00:24 -07:00
Krishna Srinivas af82d27018 signature-v4: Support for transfer-encoding request header (#4053) 2017-04-05 15:08:33 -07:00
Harshavardhana 4747adfcb4 fs: Enable returning ETag along with ListObjects() (#4042)
This is to comply with S3 behavior, we previously removed
reading `fs.json` for optimization reasons but we have a
reason to believe that providing ETag and using gjson
provides needed benefit of not having to deal with
unmarshalling overhead of golang stdlib.

Fixes #4028
2017-04-04 09:14:03 -07:00
Anis Elleuch 52d8f564bf sigv2: Unespace canonicalized resources values (#4034)
Values of canonicalized query resources should be unescaped before calculating
the signature. This bug is not noticed before because partNumber and uploadID
values in Minio doesn't have characters that need to be escaped.
2017-04-03 17:55:14 -07:00
Harshavardhana 3fe33e7b15 handler: simplify parsing valid location constraint. (#4040)
Separate out validating v/s parsing logic in
isValidLocationConstraint() into parseLocationConstraint()
and isValidLocation()

Additionally also set `X-Amz-Bucket-Region` as part of the
common headers for the clients to fallback on in-case of any
region related errors.
2017-04-03 14:50:09 -07:00
Krishnan Parthasarathi 4041e5f20d Provide mc-admin-heal command on start-up (#4031)
Healing of buckets, objects and incomplete uploads are implemented and
available via admin REST APIs. Additionally, it is available via mc admin 
sub-command. The warning is no longer relevant.

Fixes #4030
2017-04-03 14:24:25 -07:00
Harshavardhana 4de6b15fca vet: Fix all the go vet complaints (#4029)
```
go tool vet -atomic -bool -copylocks -nilfunc \
   -printf -shadow -rangeloops -unreachable \
   -unsafeptr -unusedresult cmd/
```
2017-04-01 01:06:06 -07:00
Krishnan Parthasarathi 2bd694dbc8 Add disksUnavailable healStatus const (#3990)
`disksUnavailable` healStatus constant indicates that a given object
needs healing but one or more of disks requiring heal are offline. This
can be used by admin heal API consumers to distinguish between a
successful heal and a no-op since the outdated disks were offline.
2017-03-31 17:55:15 -07:00
Aditya Manthramurthy a2a8d54bb6 Add `access` format support for Elasticsearch notification target (#4006)
This change adds `access` format support for notifications to a
Elasticsearch server, and it refactors `namespace` format support.

In the case of `access` format, for each event in Minio, a JSON
document is inserted into Elasticsearch with its timestamp set to the
event's timestamp, and with the ID generated automatically by
elasticsearch. No events are modified or deleted in this mode.

In the case of `namespace` format, for each event in Minio, a JSON
document is keyed together by the bucket and object name is updated in
Elasticsearch. In the case of an object being created or over-written
in Minio, a new document or an existing document is inserted into the
Elasticsearch index. If an object is deleted in Minio, the
corresponding document is deleted from the Elasticsearch index.

Additionally, this change upgrades Elasticsearch support to the 5.x
series. This is a breaking change, and users of previous elasticsearch
versions should upgrade.

Also updates documentation on Elasticsearch notification target usage
and has a link to an elasticsearch upgrade guide.

This is the last patch that finally resolves #3928.
2017-03-31 14:11:27 -07:00
Harshavardhana 2040d32ef8 server/tls: Do not rely on a specific cipher suite (#4021)
Do not rely on a specific cipher suite instead let the
go choose the type of cipher needed, if the connection
is coming from clients which do not support forward
secrecy let the go tls handle this automatically based
on tls1.2 specifications.

Fixes #4017
2017-03-31 13:28:45 -07:00
Harshavardhana f1015a5096 notifiers: Stop using url.Parse in validating address format. (#4011)
url.Parse() wrongly parses an address of format "address:port"
which is fixed in go1.8.  This inculcates a breaking change
on our end. We should fix this wrong usage everywhere so that
migrating to go1.8 eventually becomes smoother.
2017-03-31 04:47:40 -07:00
Aditya Manthramurthy 096427f973 Add `deliveryMode` parameter for AMQP notfication target (#4008)
Configuration migration was done.

Also adds documentation about AMQP configuration parameters.

Fixes #3982
2017-03-31 03:34:26 -07:00
Bala FA 6e9c91f43a fix: use its own lock in serverConfigV17 (#4014)
Previously serverConfigV17 used a global lock that made any instance of
serverConfigV17 depended on single global serverConfigMu.

This patch fixes by having individual lock per instances.
2017-03-30 22:26:24 -07:00
Bala FA 2df8160f6a server: handle command line and env variables at one place. (#3975) 2017-03-30 11:21:19 -07:00
Harshavardhana 28c5a887de event: Set contentType as well under NotificationEvent. (#4003)
This is an enhancement change to to cater support all
the data fields present on the object. Currently
we only send a subset of data which object info
provides us.

It also helps us keep a full namespace mirror on
notification targets for efficient query.
2017-03-30 08:58:14 -07:00
Anis Elleuch fbe8b3259d webhook: Add support of custom CAs (#4000) 2017-03-29 13:42:55 -07:00
Anis Elleuch e2aba9196f obj-handlers: Rewrite src & dst path cmp in Copy() (#3998)
CopyObjectHandler() was incorrectly performing comparison
between destination and source object paths, which sometimes
leads to a lock race. This PR simplifies comparaison and add
one test case.
2017-03-29 09:21:38 -07:00
Aditya Manthramurthy 61b08137b0 Add `access` format support for Redis notification target (#3989)
This change adds `access` format support for notifications to a Redis
server, and it refactors `namespace` format support.

In the case of `access` format, a list is used to store Minio
operations in Redis. Each entry in the list is a JSON encoded list of
two items - the first is the Minio server timestamp of the event, and
the second is an object describing the operation that created/replaced
the object in the server.

In the case of `namespace` format, a hash is used. Entries in the hash
may be updated or removed if objects in Minio are updated or deleted
respectively. The field values in the Redis hash are JSON encoded.

Also updates documentation on Redis notification target usage.

Towards resolving #3928
2017-03-29 08:55:53 -07:00
Harshavardhana 1caad902cb config/path: Figure out absolute paths properly on windows. (#3996)
The following form of arguments such as

```
minio.exe -C some_dir server dir
```

has stopped working because of lack of handling of
absolute paths for config directory. Always calculate
absolute path for any relative paths on any operating
system.

The following fix converts all config directory relative
paths into absolute paths.

Fixes #3991
2017-03-29 08:55:33 -07:00