[Breaking] Consolidate multiple flags into a few SuperFlags

[karlmcguire]

(This is related to DGRAPH-3026.)

Old Name	Old Type	New Name	New Type	Al	Ze	Bu	Ba	Li	De
		--badger
badger.compression	string	compression	string	🟢		🟢	🟢
		(new) goroutines	int	🟢		🟢	🟢
badger.cache_mb	string	cache-mb	string			🟢
badger.cache_percentage	string	cache-percentage	string			🟢
		--acl
acl_secret_file	string	secret-file	string	🟢
acl_access_ttl	time.Duration	access-ttl	string	🟢
acl_refresh_ttl	time.Duration	refresh-ttl	string	🟢
		--ludicrous
ludicrous_mode	bool	enabled	bool	🟢
ludicrous_concurrency	int	concurrency	int	🟢
		--graphql
graphql_introspection	bool	introspection	bool	🟢
graphql_debug	bool	debug	bool	🟢
graphql_extensions	bool	extensions	bool	🟢
graphql_poll_interval	time.Duration	poll-interval	string	🟢
graphql_lambda_url	string	lambda-url	string	🟢
		--raft
pending_proposals	int	pending-proposals	int	🟢
idx	int	idx	int	🟢	🟢
group	int	group	int	🟢
learner	bool	learner	bool	🟢	🟢
snapshot-after	int	snapshot-after	bool	🟢
		--security
auth_token	string	token	string	🟢
whitelist	string	whitelist	string	🟢
		--limit
query_edge_limit	uint64	query-edge	uint64	🟢
normalize_node_limit	int	normalize-node	int	🟢
mutations_nquad_limit	int	mutations-nquad	int	🟢
		--tls
tls_cacert	string	cacert	string	🟢	🟢	🟢	🟢	🟢
tls_use_system_ca	bool	use-system-ca	bool	🟢	🟢	🟢	🟢	🟢
tls_server_name	string	server-name	string	🟢	🟢	🟢	🟢	🟢
tls_client_auth	string	client-auth	string	🟢	🟢
tls_node_cert	string	node-cert	string	🟢	🟢
tls_node_key	string	node-key	string	🟢	🟢
tls_internal_port_enabled	bool	internal-port-enabled	bool	🟢	🟢	🟢	🟢	🟢
tls_cert	string	cert	string	🟢	🟢	🟢	🟢	🟢
tls_key	string	key	string	🟢	🟢	🟢	🟢	🟢
		--trace
trace	float64	ratio	float64	🟢	🟢
jaeger.collector	string	jaeger	string	🟢	🟢
datadog.collector	string	datadog	string	🟢	🟢
		--vault
vault_addr	string	addr	string	🟢		🟢	🟢	🟢	🟢
vault_roleid_file	string	role-id-file	string	🟢		🟢	🟢	🟢	🟢
vault_secretid_file	string	secret-id-file	string	🟢		🟢	🟢	🟢	🟢
vault_path	string	path	string	🟢		🟢	🟢	🟢	🟢
vault_field	string	field	string	🟢		🟢	🟢	🟢	🟢
vault_format	string	format	string	🟢		🟢	🟢	🟢	🟢

Example

Previously you could use ACL flags like this:

dgraph alpha --acl_secret_file=./secret --acl_access_ttl=21600000000000 --acl_refresh_ttl=2592000000000000

After this PR:

dgraph alpha --acl "secret-file=./secret; access-ttl=6h; refresh-ttl=30d;"

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This change is 

[karlmcguire]

Reviewable status: 5 of 103 files reviewed, 11 unresolved discussions (waiting on @danielmai, @karlmcguire, @manishrjain, @martinmr, @pawanrawal, and @vvbalaji-dgraph)

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dgraph/cmd/alpha/run.go, line 666 at r1 (raw file):

Previously, manishrjain (Manish R Jain) wrote…

ideally, this can just be parsed in the right package instead of here.

Done.

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dgraph/cmd/alpha/run.go, line 714 at r1 (raw file):

Previously, manishrjain (Manish R Jain) wrote…

Ideally, worker options only contains the SuperFlags, and lets the modules do what they need to with them.

Done.

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dgraph/cmd/alpha/run.go, line 235 at r4 (raw file):

Previously, manishrjain (Manish R Jain) wrote…

no need to use backticks if it fits in one line.

Done.

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edgraph/server.go, line 1197 at r4 (raw file):

Previously, manishrjain (Manish R Jain) wrote…

Just ensure that we're not doing this parsing in the critical path.

Done.