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Commit 23b733c3 authored by Pierre Smeyers's avatar Pierre Smeyers
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Merge branch 'feat/env-expand-enhancements' into 'master'

feat: env expand enhancements

See merge request to-be-continuous/kubernetes!88
parents b49d0d53 4023f7f8
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......@@ -144,7 +144,7 @@ Examples (with an application's base name `myapp`):
The Kubernetes template supports three techniques to deploy your code:
1. script-based deployment,
2. template-based deployment using raw Kubernetes manifests (with variables substitution),
2. template-based deployment using raw Kubernetes manifests (with [variables substitution](#variables-substitution-mechanism)),
3. template-based deployment using [Kustomization files](https://kubectl.docs.kubernetes.io/references/kustomize/kustomization/).
#### 1: script-based deployment
......@@ -167,7 +167,7 @@ in your project structure, and let the GitLab CI template [`kubectl apply`](http
The template processes the following steps:
1. _optionally_ executes the `k8s-pre-apply.sh` script in your project to perform specific environment pre-initialization (for e.g. create required services),
2. looks for your Kubernetes deployment file, performs [variables substitution](#using-variables) and [`kubectl apply`](https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#apply) it,
2. looks for your Kubernetes deployment file, performs [variables substitution](#variables-substitution-mechanism) and [`kubectl apply`](https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#apply) it,
1. look for a specific `deployment-$environment_type.yml` in your project (e.g. `deployment-staging.yml` for staging environment),
2. fallbacks to default `deployment.yml`.
3. _optionally_ executes the `k8s-post-apply.sh` script in your project to perform specific environment post-initialization stuff,
......@@ -202,7 +202,7 @@ After deployment (either script-based or template-based), the GitLab CI template
The Kubernetes template supports three techniques to destroy an environment (actually only review environments):
1. script-based deployment,
2. template-based deployment using raw Kubernetes manifests (with variables substitution),
2. template-based deployment using raw Kubernetes manifests (with [variables substitution](#variables-substitution-mechanism)),
3. template-based deployment using [Kustomization files](https://kubectl.docs.kubernetes.io/references/kustomize/kustomization/).
#### 1: script-based cleanup
......@@ -282,20 +282,26 @@ by using available environment variables:
3. any [custom variable](https://docs.gitlab.com/ee/ci/variables/#for-a-project)
(ex: `${SECRET_TOKEN}` that you have set in your project CI/CD variables)
While your scripts may simply use any of those variables, your Kubernetes and Kustomize resources can use **variable substitution**
with the syntax `${VARIABLE_NAME}`.
Each of those patterns will be dynamically replaced in your resources by the template right before using it.
#### Variables substitution mechanism
You can prevent any line from being processed by appending `# nosubst` at the end of the line.
For instance in the following example, `${REMOTE_SERVICE_NAME}` won't be replaced by its environment value during GitLab job execution:
While your scripts may freely use any of the available variables, your Kubernetes and Kustomize
resources can use a **variables substitution** mechanism implemented by the template:
- Using the syntax `${VARIABLE_NAME}` or `%{VARIABLE_NAME}`.\
:warning: Curly braces (`{}`) are mandatory in the expression (`$VARIABLE_NAME` won't be processed).
- Each of those expressions will be **dynamically expanded** in your resource files with the variable value, right before being used.
- Variable substitution expressions **must be contained in double-quoted strings**.
The substitution implementation takes care of escaping characters that need to be (double quote `"`, backslash `\`, tab `\t`, carriage return `\n` and line feed `\r`).
- Variable substitution can be prevented by appending `# nosubst` at the end of any line.\
Ex:
```yaml
apiVersion: v1
kind: ConfigMap
metadata:
# ${environment_name} will be expanded
labels:
app: ${APPLICATION_NAME}
name: ${APPLICATION_NAME}
app: "${environment_name}"
name: "${environment_name}"
data:
application.yml: |
remote:
......@@ -303,21 +309,6 @@ data:
name: '${REMOTE_SERVICE_NAME}' # nosubst
```
> :warning: In order to be properly replaced, curly braces are mandatory (ex: `${MYVAR}` and not `$MYVAR`).
> Moreover, multiline variables must be surrounded by **double quotes** (`"`).
>
> Example:
>
> ```yaml
> [...]
> containers:
> - name: restaurant-app
> env:
> # multiline variable
> - name: MENU
> value: "${APP_MENU}"
> ```
### Environments URL management
The K8S template supports two ways of providing your environments url:
......
......@@ -419,9 +419,78 @@ stages:
echo "$1" | tr '[:lower:]' '[:upper:]' | tr '[:punct:]' '_'
}
function awkenvsubst() {
# performs variables escaping: '&' for gsub + JSON chars ('\' and '"')
awk '!/# *nosubst/{while(match($0,"[$%]{[^}]*}")) {var=substr($0,RSTART+2,RLENGTH-3);val=ENVIRON[var];gsub(/["\\&]/,"\\\\&",val);gsub("[$%]{"var"}",val)}}1'
function tbc_envsubst() {
awk '
BEGIN {
count_replaced_lines = 0
# ASCII codes
for (i=0; i<=255; i++)
char2code[sprintf("%c", i)] = i
}
# determine encoding (from env or from file extension)
function encoding() {
enc = ENVIRON["TBC_ENVSUBST_ENCODING"]
if (enc != "")
return enc
if (match(FILENAME, /\.(json|yaml|yml)$/))
return "jsonstr"
return "raw"
}
# see: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent
function uriencode(str) {
len = length(str)
enc = ""
for (i=1; i<=len; i++) {
c = substr(str, i, 1);
if (index("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.!~*'\''()", c))
enc = enc c
else
enc = enc "%" sprintf("%02X", char2code[c])
}
return enc
}
!/# *nosubst/ {
orig_line = $0
line = $0
count_repl_in_line = 0
# /!\ 3rd arg (match) not supported in BusyBox awk
while (match(line, /[$%]\{([[:alnum:]_]+)\}/)) {
expr_start = RSTART
expr_len = RLENGTH
# get var name
var = substr(line, expr_start+2, expr_len-3)
# get var value (from env)
val = ENVIRON[var]
# check variable is set
if (val == "") {
printf("[\033[1;93mWARN\033[0m] Environment variable \033[33;1m%s\033[0m is not set or empty\n", var) > "/dev/stderr"
} else {
enc = encoding()
if (enc == "jsonstr") {
gsub(/["\\]/, "\\\\&", val)
gsub("\n", "\\n", val)
gsub("\r", "\\r", val)
gsub("\t", "\\t", val)
} else if (enc == "uricomp") {
val = uriencode(val)
} else if (enc == "raw") {
} else {
printf("[\033[1;93mWARN\033[0m] Unsupported encoding \033[33;1m%s\033[0m: ignored\n", enc) > "/dev/stderr"
}
}
# replace expression in line
line = substr(line, 1, expr_start - 1) val substr(line, expr_start + expr_len)
count_repl_in_line++
}
if (count_repl_in_line) {
if (count_replaced_lines == 0)
printf("[\033[1;94mINFO\033[0m] Variable expansion occurred in file \033[33;1m%s\033[0m:\n", FILENAME) > "/dev/stderr"
count_replaced_lines++
printf("> line %s: %s\n", NR, orig_line) > "/dev/stderr"
}
print line
}
' "$@"
}
function exec_hook() {
......@@ -539,8 +608,8 @@ stages:
exit 1
fi
# replace variables (alternative for envsubst which is not present in image)
awkenvsubst < "$deploymentfile" > generated-deployment.yml
# variables substitution
tbc_envsubst "$deploymentfile" > generated-deployment.yml
log_info "--- \\e[32mkubectl $action\\e[0m"
kubectl ${TRACE+-v=5} "$action" -f ./generated-deployment.yml
......@@ -562,7 +631,7 @@ stages:
export appname_ssc=$environment_name_ssc
# variables expansion in $environment_url
environment_url=$(echo "$environment_url" | awkenvsubst)
environment_url=$(echo "$environment_url" | TBC_ENVSUBST_ENCODING=uricomp tbc_envsubst)
export environment_url
# extract hostname from $environment_url
hostname=$(echo "$environment_url" | awk -F[/:] '{print $4}')
......@@ -644,7 +713,7 @@ stages:
export appname_ssc=$environment_name_ssc
# variables expansion in $environment_url
environment_url=$(echo "$environment_url" | awkenvsubst)
environment_url=$(echo "$environment_url" | TBC_ENVSUBST_ENCODING=uricomp tbc_envsubst)
export environment_url
# extract hostname from $environment_url
hostname=$(echo "$environment_url" | awk -F[/:] '{print $4}')
......@@ -755,8 +824,8 @@ stages:
exit 1
fi
# replace variables (alternative for envsubst which is not present in image)
awkenvsubst < "$deploymentfile" > generated-deployment.yml
# variables substitution
tbc_envsubst "$deploymentfile" > generated-deployment.yml
# shellcheck disable=SC2086
/usr/bin/kube-score score $K8S_SCORE_EXTRA_OPTS generated-deployment.yml
......@@ -764,7 +833,7 @@ stages:
}
# export tool functions (might be used in after_script)
export -f log_info log_warn log_error assert_defined rollback awkenvsubst
export -f log_info log_warn log_error assert_defined rollback tbc_envsubst
unscope_variables
eval_all_secrets
......
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