* .---. ,---. ,---. .-. .-. ,--, ,---. *
/.\ ( .-._)| .-.\ | .-.\ | | | |.' .') | .-' /.\
/..'\ (_) \ | |-' )| `-'/ | | | || |(_) | `-. /..'\
/'.'\ _ \ \ | |--' | ( | | | |\ \ | .-' /'.'\
/.''.'\ ( `-' ) | | | |\ \ | `-')| \ `-. | `--. /.''.'\
/.'.'.\ `----' /( |_| \)\`---(_) \____\/( __.' /.'.'.\
"'""""/'.''.'.\""'"'""""""(__)""""""""(__)"""""""""""""(__)""'""""/'.''.'.\""'"'"
^^^[_]^^^ ^^^[_]^^^
Questions? Pop in our slack channel!
spruce
is a domain-specific YAML merging tool, for generating BOSH manifests.
It was written with the goal of being the most intuitive solution for merging BOSH templates. As such, it pulls in a few semantics that may seem familiar to those used to merging with the other merging tool, but there are a few key differences.
Spruce is now available via Homebrew, just brew tap starkandwayne/cf; brew install spruce
Alternatively, you can download a prebuilt binaries for 64-bit Linux, or Mac OS X,
or you can install via go get
(provided you have installed go):
go get github.com/geofffranks/spruce/...
Merging in spruce
is designed to be pretty intuitive. Files to merge are listed
in-order on the command line. The first file serves as the base to the file structure,
and subsequent files are merged on top, adding when keys are new, replacing when keys
exist. This differs slightly in mentality from spiff, but hopefully the results are
more predictable.
meta
was a convention used quite often in templates merged with spiff. This convention
is not necessary with spruce. If you want to merge two hashes together, simply include
the new keys in the file merged on top of the original.
Arrays can be modified in multiple ways: prepending data, appending data, inserting data, merging data onto the existing data, or completely replacing data.
-
To append data to an existing array, ensure that the first element in the new array is
- (( append ))
-
To prepend the data to an existing array, ensure that the first element in the new array is
- (( prepend ))
-
To insert new elements either after or before a specific position of an existing array, you can use
insert
with a hint to the respective insertion point in the target listjobs: - name: consul instances: 1 - name: nats instances: 2 - name: ccdb instances: 2 - name: uaadb instances: 2 - name: dea instances: 8 - name: api instances: 2
jobs: - (( insert after "dea" )) - name: dea_v2 instances: 2
or
- (( insert after <key> "<name>" )) - <key>: new-kid-on-the-block
The firstinsert
is usingname
as the default key to determine the target position in the target array. The second is used to customize which key to use. In any case, instead ofafter
, you can also usebefore
. This will prepend the entries (relative to the specified insertion point). -
Similar to the
insert
operation, you can also use a(( delete ... ))
operation multiple times in a list. Thedelete
will remove a map from the listjobs: - (( delete "dea" )) - (( delete "api" ))
or
- (( delete <key> "<name>" ))
The array modification operations(( append ))
,(( prepend ))
,(( delete ... ))
, and(( insert ... ))
can be used multiple times in one list. Entries that follow(( append ))
,(( prepend ))
, and(( insert ... ))
belong to the same operation. This however does not apply to(( delete ... ))
, which always stands alone. -
To replace the first array with the second, ensure that the first element in the new array is
- (( replace ))
-
To merge two arrays by way of their index, just make the first element
- (( inline ))
-
To merge two arrays of maps together (using a specific key for identifying like objects), ensure that the first element in the new array is either
- (( merge ))
or- (( merge on <key> ))
The first merges usingname
as the key to determine like objects in the array elements. The second is used to customize which key to use. -
If you don't specify a specific merge strategy, the array will be merged automatically; using keys if they exist (i.e.
(( merge ))
, and array indices otherwise ((( inline ))
).
Do you want to learn about array modifications in more detail? See modifying arrays for examples and explanations.
To prune a map key from the final output, you can either use the --prune
flag:
spruce merge --prune key.1.to.prune --prune key.2.to.prune file1.yml file2.yml
or you can use the (( prune ))
operator:
key_to_prune: (( prune ))
If you actually want to prune everything but one or two paths from your YAML, you can use the --cherry-pick
flag to only select what you want to have in the end:
spruce merge --cherry-pick jobs --cherry-pick properties file1.yml file2.yml
The --cherry-pick
flag can be used in combination with the --prune
flag as long as you do not prune the exact path you are about to cherry-pick.
Need to reference existing data in your datastructure? No problem! spruce
will wait until
all the data is merged together before dereferencing anything, but to handle this, you can
use the (( grab <thing> ))
syntax:
data:
color: blue
pen:
color: (( grab data.color ))
You can even reference multiple values at once, getting back an array of their data, for things like getting all IPs of multi-AZ jobs in a BOSH manifest, just do it like so:
(( grab jobs.myJob_z1.networks.myNet1.static_ips jobs.myJob_z2.networks.myNet2.static_ips ))
You can also provide alternatives to your grab
operation, by
using the ||
(or) operator:
key: (( grab site.key || nil ))
domain: (( grab global.domain || "example.com" ))
protocol: (( grab site.protocol || global.protocol || "http" ))
In these examples, if the referenced key does not exist, the next reference is attempted, or the literal value (nil, numbers or strings) is used. Spruce recognizes the following keywords and uses the appropriate literal value:
nil
,null
and~
map to the YAML null valuetrue
is the YAML boolean value for truthfalse
is the YAML boolean value for non-truth
Other types of literals include double-quoted strings (with embedded double quotes escaped with a single backslash - \), integer literals (a string of digits) and floating point literals (a string of digits, a period, and another string of digits). Scientific notation is not currently supported.
Want to pull in secret credentials from your environment? No problem!
secrets:
aws:
access_key: (( grab $AWS_ACCESS_KEY ))
secret_key: (( grab $AWS_SECRET_KEY ))
spruce
will try to pull the named environment variables value
from the environment, and fail if the value is not set, or is
empty. You can use the ||
syntax to provide defaults, á la:
meta:
environment: (( grab $ENV_NAME || "default-env" ))
In some cases you may want to merge 2 or more Spruce files into one so that you can apply their logic with a single file. In other to do that, you can make use of the option --no-eval
in merge.
Check out the no-eval example
spruce
supports that too! Just use the same (( static_ips(x, y, z) ))
syntax
that you're used to with spiff,
to specify the offsets in the static IP range for a job's network.
Behind the scenes, there are a couple behavior improvements upon spiff. First,
since all the merging is done first, then post-processing, there's no need
to worry about getting the instances + networks defined before (( static_ips() ))
is merged in. Second, the error messaging output should be a lot better to aid in
tracking down why static_ips()
calls fail.
Check out the static_ips() example
This is also possible with spruce
. You can use the (( calc ... ))
operator to
specify a mathematical expression. Inside these expressions you can reference
other values using the same path syntax like grab
. The mathematical expression
needs to be put in quotes since it can contain parenthesis and white spaces
between your operators, references, or numbers.
meta:
offset: 2
jobs:
- name: one
instances: (( calc "meta.offset + 4" ))
If you have more sophisticated calculations in mind, you can use these built-in
functions inside your expressions: max
, min
, mod
, pow
, sqrt
, floor
, and ceil
.
Maybe you want to calculate instance counts based on given target value.
meta:
target_mem: 144
jobs:
- name: big_ones
instances: (( calc "floor(meta.target_mem / 32)" ))
- name: small_ones
instances: (( calc "floor((meta.target_mem - jobs.big_ones.instances * 32) / 16)" ))
Yeah, spruce
can do that!
env: production
cluster:
name: mjolnir
ident: (( concat cluster.name "//" env ))
Which will give you an ident:
key of "mjolnir/production"
But what if I have a list of strings that I want as a single line? Like a users list, authorities, or similar.
Do I have to concat
that piece by piece? No, you can use join
to concatenate a list into one entry.
meta:
authorities:
- password.write
- clients.write
- clients.read
- scim.write
properties:
uaa:
clients:
admin:
authorities: (( join "," meta.authorities ))
This will give you a concatenated list for authorities
:
properties:
uaa:
clients:
admin:
authorities: password.write,clients.write,clients.read,scim.write
Here's a pretty broad example, that should cover all the functionality of spruce, to be used as a reference.
If I start with this data:
# examples/basic/main.yml
top:
orig_key: This is a string attached to a key
number: 50
array1:
- first element
- second element
- third element
map:
key1: v1
key2: v2
key3:
subkey1: vv1
subkey2: vv2
subkey3:
- nested element 1
- nested element 2
1: 430.0
2: this starts as a string
array2:
- 1
- 2
- 3
- 4
inline_array_merge:
- will be overwritten
- this: will
be: merged
And want to merge in this:
# examples/basic/merge.yml
top:
new_key: this is added
orig_key: this is replaced
map:
key4: added key
key1: replaced key
key2: ~
key3:
subkey3:
- (( append ))
- nested element 3
array1:
- (( prepend ))
- prepend this
array2:
- over
- ridden
- array
1: You can change types too
2:
even: drastically
to: from scalars to maps/lists
inline_array_merge:
- (( inline ))
- this has been overwritten
- be: overwritten
merging: success!
othertop: you can add new top level keys too
I would use spruce
like this:
$ spruce merge main.yml merge.yml
othertop: you can add new top level keys too
top:
1: You can change types too
2:
even: drastically
to: from scalars to maps/lists
array1:
- prepend this
- first element
- second element
- third element
array2:
- over
- ridden
- array
- 4
inline_array_merge:
- this has been overwritten
- be: overwritten
merging: success!
this: will
map:
key1: replaced key
key2: null
key3:
subkey1: vv1
subkey2: vv2
subkey3:
- nested element 1
- nested element 2
- nested element 3
key4: added key
new_key: this is added
number: 50
orig_key: this is replaced
One of spiff's quirks was that it quite easily allowed you to completely replace an
entire map, with new data (rather than merging by default). That result is still
possible with spruce
, but it takes a little bit more work, since the primary
use case is to merge two maps together:
We start with this yaml:
# examples/map-replacement/original.yml
untouched:
map: stays
the: same
map_to_replace:
has: upstream
data: that
we: do
not: want
Next, create a YAML file to clear out the map:
# examples/map-replacement/delete.yml
map_to_replace: ~
Now, create a YAML file to insert the data you want in the end:
# examples/map-replacement/insert.yml
map_to_replace:
my: special
data: here
And finally, merge it all together:
$ spruce merge original.yml delete.yml insert.yml
map_to_replace:
my: special
data: here
untouched:
map: stays
the: same
<a name-"ex-key-removal">
How about deleting keys outright? Use the --prune flag to the merge command:
# examples/key-removal/original.yml
deleteme:
thing:
foo: 1
bar: 2
# examples/key-removal/things.yml
things:
- name: first-thing
foo: (( grab deleteme.thing.foo ))
- name: second-thing
bar: (( grab deleteme.thing.bar ))
$ spruce merge --prune deleteme original.yml things.yml
The deleteme
key is only useful for holding a temporary value,
so we'd really rather not see it in the final output. --prune
drops it.
Let's say you have a list of maps that you would like to merge into another list of maps, while preserving as much data as possible.
Given this original.yml
:
# examples/list-of-maps/original.yml
jobs:
- name: concatenator_z1
instances: 5
resource_pool: small
properties:
spruce: is cool
- name: oldjob_z1
instances: 4
resource_pool: small
properties:
this: will show up in the end
And this new.yml
:
# examples/list-of-maps/new.yml
jobs:
- name: newjob_z1
instances: 3
resource_pool: small
properties:
this: is a job defined solely in new.yml
- name: concatenator_z1
properties:
this: is a new property added to an existing job
You would get this when merged:
$ spruce merge original.yml new.yml
jobs:
- instances: 5
name: concatenator_z1
properties:
spruce: is cool
this: is a new property added to an existing job
resource_pool: small
- instances: 4
name: oldjob_z1
properties:
this: will show up in the end
resource_pool: small
- instances: 3
name: newjob_z1
properties:
this: is a job defined solely in new.yml
resource_pool: small
Pretty sweet, huh?
Lets define our jobs.yml
:
# examples/static-ips/jobs.yml
jobs:
- name: staticIP_z1
instances: 3
networks:
- name: net1
static_ips: (( static_ips(0, 2, 4) ))
- name: api_z1
instances: 3
networks:
- name: net1
static_ips: (( static_ips(1, 3, 5) ))
Next, we'll define our properties.yml
:
# examples/static-ips/properties.yml
properties:
staticIP_servers: (( grab jobs.staticIP_z1.networks.net1.static_ips ))
api_servers: (( grab jobs.api_z1.networks.net1.static_ips ))
And lastly, define our networks.yml
:
# examples/static-ips/networks.yml
networks:
- name: net1
subnets:
- cloud_properties: random
static:
- 192.168.0.2 - 192.168.0.10
Merge it all together, and see what we get:
$ spruce merge jobs.yml properties.yml networks.yml
jobs:
- instances: 3
name: staticIP_z1
networks:
- name: net1
static_ips:
- 192.168.0.2
- 192.168.0.4
- 192.168.0.6
- instances: 3
name: api_z1
networks:
- name: net1
static_ips:
- 192.168.0.3
- 192.168.0.5
- 192.168.0.7
networks:
- name: net1
subnets:
- cloud_properties: random
static:
- 192.168.0.2 - 192.168.0.10
properties:
api_servers:
- 192.168.0.3
- 192.168.0.5
- 192.168.0.7
staticIP_servers:
- 192.168.0.2
- 192.168.0.4
- 192.168.0.6
Lets define our jobs.yml
:
# examples/availability-zones/jobs.yml
instance_groups:
- name: staticIP
instances: 3
azs: [z1,z2]
networks:
- name: net1
static_ips: (( static_ips(0, "z2:2", "z1:3") ))
- name: api
instances: 3
azs: [z1]
networks:
- name: net1
static_ips: (( static_ips(1, "z1:4", 5) ))
- name: web
instances: 3
networks:
- name: net1
static_ips: (( static_ips(9, 10, 11) ))
Next, we'll define our properties.yml
:
# examples/availability-zones/properties.yml
properties:
staticIP_servers: (( grab instance_groups.staticIP.networks.net1.static_ips ))
api_servers: (( grab instance_groups.api.networks.net1.static_ips ))
web_servers: (( grab instance_groups.web.networks.net1.static_ips ))
And lastly, define our networks.yml
:
# examples/availability-zones/networks.yml
networks:
- name: net1
subnets:
- cloud_properties: random
az: z1
static:
- 192.168.0.1 - 192.168.0.10
- cloud_properties: random
az: z2
static:
- 192.168.2.1 - 192.168.2.10
Merge it all together, and see what we get:
$ spruce merge jobs.yml properties.yml networks.yml
instance_groups:
- name: staticIP
instances: 3
azs: [z1,z2]
networks:
- name: net1
static_ips:
- 192.168.0.1
- 192.168.2.3
- 192.168.0.4
- name: api
instances: 3
azs: [z1]
networks:
- name: net1
static_ips:
- 192.168.0.2
- 192.168.0.5
- 192.168.0.6
- name: web
instances: 3
networks:
- name: net1
static_ips:
- 192.168.0.10
- 192.168.2.1
- 192.168.2.2
networks:
- name: net1
subnets:
- cloud_properties: random
az: z1
static:
- 192.168.0.1 - 192.168.0.10
- cloud_properties: random
az: z2
static:
- 192.168.2.1 - 192.168.2.10
properties:
api_servers:
- 192.168.0.2
- 192.168.0.5
- 192.168.0.6
staticIP_servers:
- 192.168.0.1
- 192.168.2.3
- 192.168.0.4
web_servers:
- 192.168.0.10
- 192.168.2.1
- 192.168.2.2
One of the great things about YAML is the oft-overlooked <<
inject operator, which lets you start with a copy of another part
of the YAML tree and override keys, like this:
# examples/inject/all-in-one.yml
meta:
template: &template
color: blue
size: small
green:
<<: *template
color: green
Here, $.green.size
will be small
, but $.green.color
stays as
green
:
$ spruce merge --prune meta all-in-one.yml
green:
color: green
size: small
That works great if you are in the same file, but what if you want to inject data from a different file into your current map and then override some things?
That's where (( inject ... ))
really shines.
# examples/inject/templates.yml
meta:
template:
color: blue
size: small
# examples/inject/green.yml
green:
woot: (( inject meta.template ))
color: green
$ spruce merge --prune meta templates.yml green.yml
green:
color: green
size: small
Note: The key used for the (( inject ... ))
call (in this
case, woot
) is removed from the final tree as part of the
injection operator.
This option can be used to merge several stubs without evaluating the spruce logic inside such as (( grab ))
or (( concat ))
. For instance, if you have the following two files:
$ cat first.yml
jobs:
- name: cell
templates:
- name: garden
$ cat second.yml
jobs:
- name: cc_bridge
- name: router
- name: cell
templates:
- (( prepend ))
- name: metron_agent
properties:
diego: (( grab meta.diego_enabled ))
You could merge them simply running:
$ spruce merge --skip-eval first.yml second.yml
jobs:
- name: cell
templates:
- name: metron_agent
- name: garden
- name: cc_bridge
- name: router
properties:
diego: (( grab meta.diego_enabled ))
Sometimes you need to include large blocks of text in your YAML, such as the body of a configuration file, or a script block. However, the indentation can cause issues when that block needs to be edited later, and there's no easy way to use tools to validate the block.
Using the (( file ... ))
operator allows you to keep the block in its
natural state to allow for easy viewing, editing and processing, but then add
it to YAML file as needed. It supports specifying the file either by a string
literal or a reference.
The relative path to the file is based on where spruce is run from.
Alternatively, you can set the SPRUCE_FILE_BASE_PATH
environment variable to
the desired root that your YAML file uses as the reference to the relative
file paths specified. You can also specify an absolute path in the YAML
$ SPRUCE_FILE_BASE_PATH=$HOME/myproj/configs
--- # Source file
server:
nginx:
name: nginx.conf
config_file: (( file server.nginx.name ))
haproxy:
name: haproxy.cfg
config_file: (( file "/haproxy/haproxy.cfg" ))
The server.nginx.config_file
will contain the contents of
$HOME/myproj/configs/nginx.conf
, while the server.haproxy.config_file
will
contain the contents of /haproxy/haproxy.cfg
Sometimes, you may want to start with a good starting-point template, but require other YAML files to provide certain values. Parameters to the rescue!
# examples/params/global.yml
disks:
small: 4096
medium: 8192
large: 102400
networks: (( param "please define the networks" ))
os:
- ubuntu
- centos
- fedora
And then combine that with these local definitions:
# examples/params/local.yml
disks:
medium: 16384
networks:
- name: public
range: 10.40.0.0/24
- name: inside
range: 10.60.0.0/16
This works, but if local.yml
forgot to specify the top-level
networks key, or an error should be emitted.
Written By Geoff Franks and James Hunt, inspired by spiff
Thanks to Long Nguyen for breaking it repeatedly in the interest of improvement and quality assurance.
Licensed under the MIT License