Added StructuredStats method to returned structured stat data #56
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iptables/iptables.go
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| structStats := []Stat{} | ||
| for _, rawStat := range rawStats { | ||
| if len(rawStat) != 10 { |
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Is it possible that this will ever be 11? In other words, could iptables add new stats?
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I don't think this is likely, but it is possible.
I can omit this check and instead leave it to the parsing (mentioned below) to handle returning an error if the datatypes are mismatched or the number of fields is not within the expected range.
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I moved this check into the ParseStat method, but made it a minimum of 10 stats in a row to allow for forward compatibility.
iptables/iptables.go
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| @@ -72,6 +72,20 @@ type IPTables struct { | |||
| mode string // the underlying iptables operating mode, e.g. nf_tables | |||
| } | |||
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| // Stat represents a structured statistic entry. | |||
| type Stat struct { | |||
| Packets string `json:"pkts"` | |||
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Can you parse all numbers accordingly?
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Good catch. I will make this change.
| @@ -263,6 +277,29 @@ func (ipt *IPTables) Stats(table, chain string) ([][]string, error) { | |||
| return rows, nil | |||
| } | |||
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| // StructuredStats returns statistics as structured data which may be further | |||
| // parsed and marshaled. | |||
| func (ipt *IPTables) StructuredStats(table, chain string) ([]Stat, error) { | |||
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I suggest you add a separate ParseStats function that just takes a []string and parses the stats accordingly.
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I originally was going to do exactly that. The only issue I foresee is that exposing a ParseStats method that accepts an arbitrary []string (or [][]string) may be subject to misuse.
Anyway, two questions I'm looking for your feedback on:
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I can make a
ParseStat(stat []string) (Stat, error)and/or aParseStats(stats [][]string) ([]Stat, error). Any preference for either or both? -
Would you like me to remove
StructuredStats(table, chain string) ([]Stat, error)completely?
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BTW, I pushed up a contribution with ParseStat(stat []string) (Stat, error) and left StructuredStats(table, chain string) ([]Stat, error) for now pending feedback.
iptables/iptables.go
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| Opt string `json:"opt"` | ||
| Input string `json:"in"` | ||
| Output string `json:"out"` | ||
| Source string `json:"source"` |
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I forget - can these be hostnames, or do they have to be IP addresses? If they have to be IP addresses, can you parse them accordingly?
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The method Stats(...) uses the -n flag. From the man pages:
--numeric -n numeric output of addresses and ports
This shows the source and destination in CIDR format. Below is some output:
$ iptables --version
iptables v1.4.21
$ iptables -t filter -L INPUT -n -v -x
Chain INPUT (policy ACCEPT 12 packets, 857 bytes)
pkts bytes target prot opt in out source destination
2 128 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:3332
$ iptables -t filter -L INPUT -v -x
Chain INPUT (policy ACCEPT 43 packets, 3073 bytes)
pkts bytes target prot opt in out source destination
2 128 ACCEPT tcp -- any any anywhere anywhere tcp dpt:mcs-mailsvr
From this, we know it will be CIDR notation IP addresses.
We can call this struct NumericalStats to be more accurate. Since it's already granular, I don't think this is necessary.
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FYI, I won't have computer access for a few weeks. So apologies in advance for the radio silence. |
…d Stat struct with data types
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Hi @squeed, just a friendly request to revisit this if appropriate. Thanks! |
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@asilvr sorry, this fell off the stack. Looks good to me! |
This additional method maintains the currently available
Statsmethod while adding aStructuredStatsmethod, which returns structured data instead of a slice of string slices with statistics. This allows the caller to use a defined data structure for accessing fields in a specific statistic.Although a caller could peer into the existing
Statsmethod to determine what each field is, providing this abstraction allows for more portability/usability.