Warning added while creating the distributed pool (#317)

```
$ kadalu pool create pool1 replica 3             \
    server1:/data1 server2:/data2 server3:/data3 \
    server4:/data4 server5:/data5 server6:/data6
Using a distributed pool for small-volume claims may degrade
the performance of the volume. Consider creating multiple
Storage pools without distribution enabled if it suits your needs.

Are you sure you want to create a distributed pool? [y/N]:
```

Use `--mode=script` or `--distribute` flag to disable this
warning.

Signed-off-by: Aravinda Vishwanathapura <[email protected]>

mgr/src/cmds/pools.cr

@@ -4,7 +4,7 @@ require "./gluster_volume_parser"
 
 struct PoolArgs
   property status = false, detail = false, name = "", pool_id = "", no_start = false,
-    auto_add_nodes = false,
+    auto_add_nodes = false, distribute = false,
     node_maps = Hash(String, String).new, volfiles_separator = " "
 end
 
@@ -23,6 +23,9 @@ command "pool.create", "Kadalu Storage Pool Create" do |parser, args|
   parser.on("--auto-add-nodes", "Automatically add nodes to the pool") do
     args.pool_args.auto_add_nodes = true
   end
+  parser.on("--distribute", "Create a distributed pool") do
+    args.pool_args.distribute = true
+  end
   parser.on("--node-map=NODEMAP", "Provide node mapping while importing.\nExample: --node-map=\"server1.example.com=node1.example.com\"") do |node|
     old_name, new_name = node.split("=")
     args.pool_args.node_maps[old_name] = new_name
@@ -47,6 +50,16 @@ handler "pool.create" do |args|
       req.pool_id = args.pool_args.pool_id
     end
 
+    if req.distribute_groups.size > 1 && !args.pool_args.distribute
+      next unless (args.script_mode || yes(<<-YES_MSG))
+         Using a distributed pool for small-volume claims may degrade
+         the performance of the volume. Consider creating multiple
+         Storage pools without distribution enabled if it suits your needs.
+
+         Are you sure you want to create a distributed pool? [y/N]
+         YES_MSG
+    end
+
     req.no_start = args.pool_args.no_start
     req.auto_add_nodes = args.pool_args.auto_add_nodes
     api_call(args, "Failed to create pool") do |client|

tests/all/node_proxy_tests.t

@@ -33,7 +33,7 @@ USE_NODE nodes[1]
 puts TEST "kadalu user login admin --password=kadalu"
 
 # Distribute
-TEST "kadalu pool create vol1 server1:/exports/vol1/s1 server2:/exports/vol1/s2 server3:/exports/vol1/s3"
+TEST "kadalu pool create vol1 server1:/exports/vol1/s1 server2:/exports/vol1/s2 server3:/exports/vol1/s3 --distribute"
 
 nodes.each do |node|
   USE_NODE node

tests/all/pools.t

@@ -49,7 +49,7 @@ end
 
 USE_NODE nodes[0]
 # Distribute
-TEST "kadalu pool create pool1 server1:/exports/pool1/s1 server2:/exports/pool1/s2 server3:/exports/pool1/s3"
+TEST "kadalu pool create pool1 --distribute server1:/exports/pool1/s1 server2:/exports/pool1/s2 server3:/exports/pool1/s3"
 
 # Replicate
 TEST "kadalu pool create pool2 replica server1:/exports/pool2/s1 server2:/exports/pool2/s2 server3:/exports/pool2/s3"
@@ -58,7 +58,7 @@ TEST "kadalu pool create pool2 replica server1:/exports/pool2/s1 server2:/export
 TEST "kadalu pool create pool3 data server1:/exports/pool3/s1 server2:/exports/pool3/s2 redundancy server3:/exports/pool3/s3"
 
 # Distributed Replicate
-TEST "kadalu pool create pool4 replica server1:/exports/pool4/s1 server2:/exports/pool4/s2 server3:/exports/pool4/s3 replica server1:/exports/pool4/s4 server2:/exports/pool4/s5 server3:/exports/pool4/s6"
+TEST "kadalu pool create pool4 --distribute replica server1:/exports/pool4/s1 server2:/exports/pool4/s2 server3:/exports/pool4/s3 replica server1:/exports/pool4/s4 server2:/exports/pool4/s5 server3:/exports/pool4/s6"
 
 puts TEST "kadalu pool list --json"
 
@@ -101,7 +101,7 @@ nodes.each do |node|
 end
 
 USE_NODE nodes[0]
-TEST "kadalu pool create pool5 server1:/exports/pool5/s1 server2:/exports/pool5/s2 server3:/exports/pool5/s3 --auto-add-nodes"
+TEST "kadalu pool create pool5 server1:/exports/pool5/s1 server2:/exports/pool5/s2 server3:/exports/pool5/s3 --auto-add-nodes --distribute"
 TEST "kadalu pool stop pool5 --mode=script"
 TEST "kadalu pool delete pool5 --mode=script"
 
@@ -117,16 +117,16 @@ end
 # Case 1
 # Create pool6 & delete it. Reuse the same path with --pool-id for pool7.
 USE_NODE nodes[0]
-pool_id = create_pool_and_get_id("kadalu pool create pool6 server1:/exports/pool6/s1 server2:/exports/pool6/s2 server3:/exports/pool6/s3 --no-start")
+pool_id = create_pool_and_get_id("kadalu pool create pool6 server1:/exports/pool6/s1 server2:/exports/pool6/s2 server3:/exports/pool6/s3 --no-start --distribute")
 TEST "kadalu pool delete pool6 --mode=script"
-new_pool_id = create_pool_and_get_id("kadalu pool create pool7 server1:/exports/pool6/s1 server2:/exports/pool6/s2 server3:/exports/pool6/s3 --no-start --pool-id=#{pool_id}")
+new_pool_id = create_pool_and_get_id("kadalu pool create pool7 server1:/exports/pool6/s1 server2:/exports/pool6/s2 server3:/exports/pool6/s3 --no-start --pool-id=#{pool_id} --distribute")
 EQUAL pool_id, new_pool_id, "Checking if pool-id are equal after pool6 is reused with --pool-id in pool7"
 TEST "kadalu pool delete pool7 --mode=script"
 
 # Case 2
 # Create pool8. Create pool9 with --pool-id of active pool8.
-pool_id = create_pool_and_get_id("kadalu pool create pool8 server1:/exports/pool8/s1 server2:/exports/pool8/s2 server3:/exports/pool8/s3 --no-start")
-TEST 1, "kadalu pool create pool9 server1:/exports/pool9/s1 server2:/exports/pool9/s2 server3:/exports/pool9/s3 --no-start --pool-id=#{pool_id}"
+pool_id = create_pool_and_get_id("kadalu pool create pool8 server1:/exports/pool8/s1 server2:/exports/pool8/s2 server3:/exports/pool8/s3 --no-start --distribute")
+TEST 1, "kadalu pool create pool9 server1:/exports/pool9/s1 server2:/exports/pool9/s2 server3:/exports/pool9/s3 --no-start --pool-id=#{pool_id} --distribute"
 TEST "kadalu pool delete pool8 --mode=script"
 
 # Case 3
@@ -136,17 +136,17 @@ TEST "kadalu pool delete pool10 --mode=script"
 
 # Case 4 [Negation of Case1]
 # Create pool11 & delete it. Create pool12 with same path of unactive pool11 without --pool-id.
-TEST "kadalu pool create pool11 server1:/exports/pool11/s1 server2:/exports/pool11/s2 server3:/exports/pool11/s3 --no-start"
+TEST "kadalu pool create pool11 server1:/exports/pool11/s1 server2:/exports/pool11/s2 server3:/exports/pool11/s3 --no-start --distribute"
 TEST "kadalu pool delete pool11 --mode=script"
-TEST 1, "kadalu pool create pool12 server1:/exports/pool11/s1 server2:/exports/pool11/s2 server3:/exports/pool11/s3 --no-start"
+TEST 1, "kadalu pool create pool12 server1:/exports/pool11/s1 server2:/exports/pool11/s2 server3:/exports/pool11/s3 --no-start --distribute"
 
 # Case 5
 # Create pool13 with fresh path & no xattrs using --pool-id with wrong format. [Check for matching format of pool-id with uuid]
-TEST 1, "kadalu pool create pool13 server1:/exports/pool12/s1 server2:/exports/pool12/s2 server3:/exports/pool12/s3 --no-start --pool-id=123-456-789"
+TEST 1, "kadalu pool create pool13 server1:/exports/pool12/s1 server2:/exports/pool12/s2 server3:/exports/pool12/s3 --no-start --pool-id=123-456-789 --distribute"
 
 
 # Tests for restarting of all services on node-reboot
-TEST "kadalu pool create pool14 server1:/exports/pool14/s1 server2:/exports/pool14/s2 server3:/exports/pool14/s3"
+TEST "kadalu pool create pool14 server1:/exports/pool14/s1 server2:/exports/pool14/s2 server3:/exports/pool14/s3 --distribute"
 nodes.each do |node|
   USE_NODE node
   puts TEST "ps aux | grep 'glusterfsd'"
@@ -220,7 +220,7 @@ TEST "kadalu pool stop pool_volfile --mode=script"
 TEST "kadalu pool delete pool_volfile --mode=script"
 
 # Tests for Backup & Restore
-TEST "kadalu pool create pool19 server1:/exports/pool19/s1 server2:/exports/pool19/s2 server3:/exports/pool19/s3"
+TEST "kadalu pool create pool19 server1:/exports/pool19/s1 server2:/exports/pool19/s2 server3:/exports/pool19/s3 --distribute"
 USE_NODE nodes[0]
 TEST "kadalu config-snapshot create snap1"
 puts TEST "kadalu config-snapshot list"
@@ -237,7 +237,7 @@ TEST "kadalu pool delete pool19 --mode=script"
 
 # Tests for pool expansion
 # Distribute
-TEST "kadalu pool create pool15 server1:/exports/pool15/s1 server2:/exports/pool15/s2 server3:/exports/pool15/s3"
+TEST "kadalu pool create pool15 server1:/exports/pool15/s1 server2:/exports/pool15/s2 server3:/exports/pool15/s3 --distribute"
 TEST "mkdir -p /mnt/pool15"
 puts TEST "kadalu mount pool15 /mnt/pool15"
 puts TEST "df /mnt/pool15"
@@ -336,7 +336,7 @@ TEST "kadalu pool stop pool16 --mode=script"
 TEST "kadalu pool delete pool16 --mode=script"
 
 # Distributed Replicate
-TEST "kadalu pool create pool17 replica server1:/exports/pool17/s1 server2:/exports/pool17/s2 server3:/exports/pool17/s3 replica server1:/exports/pool17/s4 server2:/exports/pool17/s5 server3:/exports/pool17/s6"
+TEST "kadalu pool create pool17 --distribute replica server1:/exports/pool17/s1 server2:/exports/pool17/s2 server3:/exports/pool17/s3 replica server1:/exports/pool17/s4 server2:/exports/pool17/s5 server3:/exports/pool17/s6"
 TEST "mkdir -p /mnt/pool17"
 puts TEST "kadalu mount pool17 /mnt/pool17"
 puts TEST "df /mnt/pool17"
@@ -482,7 +482,7 @@ puts TEST "kadalu config-snapshot list"
 # Tests for renaming of pool
 USE_NODE nodes[0]
 TEST "kadalu pool create pool20a server1:/exports/pool20a/s1 --no-start"
-TEST "kadalu pool create pool20b server1:/exports/pool20b/s1 server2:/exports/pool20b/s2 server3:/exports/pool20b/s3 --no-start"
+TEST "kadalu pool create pool20b server1:/exports/pool20b/s1 server2:/exports/pool20b/s2 server3:/exports/pool20b/s3 --no-start --distribute"
 TEST 1, "kadalu pool rename pool20b pool20b"
 
 TEST "kadalu pool delete pool20a --mode=script"